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	2022-12-14: How Can Matter Be BOTH Liquid AND Gas? 03:45: To start with, both are fluids - they flow. 14:26: ... to think of it, let’s not review all the states of matter, because I’m starting to think there may be no end to the weird ways that matter can ... 16:31: Let’s start with quasiparticles. 14:26: ... to think of it, let’s not review all the states of matter, because I’m starting to think there may be no end to the weird ways that matter can ...
	2022-12-08: How Are Quasiparticles Different From Particles? 00:44: Let’s start our discussion of quasiparticles by talking about the particular quasiparticle that lets me talk to you about quasiparticles right now.
	2022-11-23: How To See Black Holes By Catching Neutrinos 04:17: ... are not slowed down, so the electron or muon that it creates also start out with a speed faster than the reduced speed of light in the ... 05:01: A grid of over 5000 photomultiplies spans a cubic kilometer of the glacier, starting at a depth of 1.5km. 11:09: So that means we can finally start doing real neutrino astrophysics. 15:40: And by the way kids - if you start seeing mysterious flashes, you might be one of those lucky few, but you should talk to your doctor anyway. 05:01: A grid of over 5000 photomultiplies spans a cubic kilometer of the glacier, starting at a depth of 1.5km.
	2022-11-16: Are there Undiscovered Elements Beyond The Periodic Table? 01:17: To understand the possibility of new artificial elements let's start with the story of the first artificial element. 01:38: ... time you add a proton to the nucleus, until the shell fills and you start over, filling the next shell ... 18:57: ... times on early, except for the fact that once one incident of life got started and made progress, it would be very difficult for it to happen a second ...
	2022-11-09: What If Humanity Is Among The First Spacefaring Civilizations? 03:32: ... start with a function called the appearance rate, which tells us how ... 04:05: ... figure out the appearance rate function, the researchers start with what we know about when habitable worlds formed in the past or when ...
	2022-10-26: Why Did Quantum Entanglement Win the Nobel Prize in Physics? 01:22: Let’s start with a simple thought experiment. 16:01: Let’s start with the solar gravitational lens. 18:21: The idea here was to give you a taste of its contents, and perhaps a starting point for further investigation.
	2022-10-19: The Equation That Explains (Nearly) Everything! 01:02: ... Standard Model. We finally have what we need to bring it together. Let’s start by recalling how the standard model itself got started. One of the most ...
	2022-10-12: The REAL Possibility of Mapping Alien Planets! 01:25: ... But if we can get a telescope into the “SGLF”,   then we could start making detailed desk globes of alien worlds. Let’s talk about how ... 09:31: ... spacecraft starts out by launching  backwards compared to Earth’s orbital ... 10:07: ... the Sun’s gravitational field creates a focal line, starting at 550 astronomical units,   and extending indefinitely, with ... 01:25: ... But if we can get a telescope into the “SGLF”,   then we could start making detailed desk globes of alien worlds. Let’s talk about how we ... 10:07: ... the Sun’s gravitational field creates a focal line, starting at 550 astronomical units,   and extending indefinitely, with ... 07:45: ... the Sun. To reach   the speeds we need, our spacecraft can’t start their outward journey from the Earth - they   needs to get closer to ... 09:31: ... spacecraft starts out by launching  backwards compared to Earth’s orbital ...
	2022-09-28: Why Is 1/137 One of the Greatest Unsolved Problems In Physics? 03:54: ... splitting of spectral lines it would be just a fun oddity, except this started to show up ... 06:37: So it’s starting to make sense why the fine structure constant appears in all of these formulas that depend on the electromagnetic force. 11:03: Let’s start by thinking about the similarly prolific constants of nature - the ones that actually have units. 03:54: ... splitting of spectral lines it would be just a fun oddity, except this started to show up ... 01:34: As with much of quantum mechanics, it started  with us watching the light produced as electrons flicked between energy levels in atoms. 06:37: So it’s starting to make sense why the fine structure constant appears in all of these formulas that depend on the electromagnetic force.
	2022-09-21: Science of the James Webb Telescope Explained! 01:52: ... planning picked up over the 90s, and pretty quickly core properties started to crystalize for what was then the “Next Generation Space Telescope” ... 05:52: Let’s start by looking at how most working astrophysicists hope to use JWST. 10:41: How could YOU get started doing something with this telescope? 12:34: Let’s start with the strong force. 14:20: Quantum chromodynamics actually started to explain was going on, so it suplanted hadronic string theory. 14:45: ... still failing to produce a slam-dunk testable prediciton, people are starting to take the prodigious math developed for the theory and apply it to ... 01:52: ... planning picked up over the 90s, and pretty quickly core properties started to crystalize for what was then the “Next Generation Space Telescope” ... 10:41: How could YOU get started doing something with this telescope? 14:20: Quantum chromodynamics actually started to explain was going on, so it suplanted hadronic string theory. 14:45: ... the theory and apply it to other places - including back to where it all started - gluon ...
	2022-09-14: Could the Higgs Boson Lead Us to Dark Matter? 02:05: Let’s start by looking at how we detect new particles in general.
	2022-08-24: What Makes The Strong Force Strong? 01:29: ... came in the 1940s when we switched on our first particle colliders and started to detect a veritable zoo of new ... 16:52: Starting with Lattice QCD, although the questions are more generally about particle physics. 01:29: ... came in the 1940s when we switched on our first particle colliders and started to detect a veritable zoo of new ... 16:52: Starting with Lattice QCD, although the questions are more generally about particle physics.
	2022-08-17: What If Dark Energy is a New Quantum Field? 03:33: ... but also the positive gravity of all other matter. And it’s only getting started. As the universe gets bigger and galaxies get further and further apart, ... 10:55: ... the density of matter. And it only becomes dark-energy-like when matter starts to thin out. That provides a natural explanation for why dark energy ... 03:33: ... but also the positive gravity of all other matter. And it’s only getting started. As the universe gets bigger and galaxies get further and further apart, ... 10:55: ... the density of matter. And it only becomes dark-energy-like when matter starts to thin out. That provides a natural explanation for why dark energy ...
	2022-08-03: What Happens Inside a Proton? 00:00: ... we ever want to simulate a universe, we should probably start by learning to simulate even a   single atomic nucleus. But ... 06:37: ... even with computers. Now Before any particle physicists start shouting at me,   I’ll quickly add the caveat that there are ... 07:53: ... need to account for all possible paths between   the starting and final field configuration to  get the probability of that ... 10:18: ... number of ways that the field can move   from the starting to final configuration.  And because these configurations are ... 10:43: ... configurations of a pixelated space   that get us from the start to  the end of our interaction.   But these can’t be ... 06:37: ... even with computers. Now Before any particle physicists start shouting at me,   I’ll quickly add the caveat that there are ... 10:43: ... configurations of a pixelated space   that get us from the start to  the end of our interaction.   But these can’t be totally ... 07:53: ... need to account for all possible paths between   the starting and final field configuration to  get the probability of that ... 10:18: ... number of ways that the field can move   from the starting to final configuration.  And because these configurations are ...
	2022-07-27: How Many States Of Matter Are There? 04:55: Let’s start our search for some new states of matter by exploring in the direction we started. 09:30: ... how those grains of sand interact with each other, and the sand will start acting like a ... 10:21: It starts behaving like a liquid. 09:30: ... how those grains of sand interact with each other, and the sand will start acting like a ... 04:55: Let’s start our search for some new states of matter by exploring in the direction we started. 10:21: It starts behaving like a liquid.
	2022-07-20: What If We Live in a Superdeterministic Universe? 08:28: Alice and Bob start out together, acquire their entangled electrons, and then move sideways in space and up in time. 08:56: Now let’s look at the case where the electrons start out with defined spins.
	2022-06-30: Could We Decode Alien Physics? 00:00: ... - I mean, we live in the same universe after all.   We start by noticing that the alien technology seems to use good ol’ ... 10:41: ... - appears to bring our equations   back to where they started. This is CP symmetry. A mirror-reflected, antimatter universe has ...
	2022-06-22: Is Interstellar Travel Impossible? 07:38: They start to burn up almost as soon as they enter its upper layers, where the air is only a millionth the density of sea-level.
	2022-06-15: Can Wormholes Solve The Black Hole Information Paradox? 05:20: ... radiation is produced,   but then at some point the entropy starts to  drop again because the information from past   ...
	2022-06-01: What If Physics IS NOT Describing Reality? 01:41: ... a recent episode we started talking  about informational interpretations   of quantum ... 04:56: ... simplest way to start is to look at a  quantum system where the answer to a ... 05:53: ... rotating  the Stern Gerlach apparatus 90 degrees.   You started out with one bit of knowledge  about the particle’s up-down ... 01:41: ... a recent episode we started talking  about informational interpretations   of quantum ... 05:53: ... rotating  the Stern Gerlach apparatus 90 degrees.   You started out with one bit of knowledge  about the particle’s up-down ... 01:41: ... a recent episode we started talking  about informational interpretations   of quantum mechanics. ...
	2022-05-25: The Evolution of the Modern Milky Way Galaxy 14:38: ... bound systems like the Milky Way.   Let's start with the habitable zone: In that episode I said that parts of the ... 16:41: ... of heavy elements - which was  perhaps necessary for life to get started.   The late heavy bombardment was a massive  meteor shower that lasted ... 14:08: ... work. There’s   a link in the description, so everyone can start  exploring Search.pbsspacetime.com right ... 14:38: ... giants form when   a large enough rocky or icy core forms to start  holding on to hydrogen and helium atmospheres.   That needs to ... 14:08: ... work. There’s   a link in the description, so everyone can start  exploring Search.pbsspacetime.com right ... 14:38: ... giants form when   a large enough rocky or icy core forms to start  holding on to hydrogen and helium atmospheres.   That needs to happen ...
	2022-05-18: What If the Galactic Habitable Zone LIMITS Intelligent Life? 04:32: ... surface. So it sounds like the galaxy should  be full of potential starting points for life,   even if we assume that life can  only ... 06:56: ... the universe after the Big Bang. As  it cooled, our local lump started to pull itself   together under its own gravity. Fragments ... 10:48: ... Galactic habitable zone. It emerged around 8  billion years ago, starting out as a band between   around 20 and 30 thousand light years ... 11:12: ... on the Milky Way’s formation history, our  starting intuition seems right: the Sun and solar   system are NOT ... 13:03: ... probes. But it seems that most earth-analogs have   a head start of a billion years - more than  enough time to establish galactic ... 06:56: ... the universe after the Big Bang. As  it cooled, our local lump started to pull itself   together under its own gravity. Fragments ... 11:12: ... systems accounting for all the stuff we talked  about. They started with the Milky Way’s history   of star formation and folded in ... 06:56: ... systems could have formed in the first place. Our galaxies started   like all galaxies - as a slightly overdense spot  in the near ... 04:32: ... surface. So it sounds like the galaxy should  be full of potential starting points for life,   even if we assume that life can  only ... 10:48: ... Galactic habitable zone. It emerged around 8  billion years ago, starting out as a band between   around 20 and 30 thousand light years ... 11:12: ... on the Milky Way’s formation history, our  starting intuition seems right: the Sun and solar   system are NOT ... 04:32: ... surface. So it sounds like the galaxy should  be full of potential starting points for life,   even if we assume that life can  only form on ...
	2022-05-04: Space DOES NOT Expand Everywhere 09:16: ... general relativity, space can be infinitely divided. That means we can start with a universe that’s small and grid it up and watch it expand. The ... 09:38: ... one of those points traces a path back to the big bang. We can make the starting grid as fine as we like and get the same result. Every point in the ... 14:34: ... logical inference in the style of Descartes. They felt it dishonest to start their train of reasoning with statements about external factors that ... 09:38: ... one of those points traces a path back to the big bang. We can make the starting grid as fine as we like and get the same result. Every point in the ...
	2022-04-27: How the Higgs Mechanism Give Things Mass 05:38: ... and they end up all aligning.  The equations of magnetism don’t start out with a   preferred orientation, but in certain conditions ... 06:43: ... middle.   The system is still symmetric, but if the  ball starts at the top of the hill it will   randomly roll down into one ...
	2022-04-20: Does the Universe Create Itself? 01:59: ... to explain the universe, let’s review some quantum weirdness. We’ll start with the good ol’ Schrodinger’s cat thought experiment, devised by ... 04:14: ... satisfied with any of the proposed quantum interpretations. Although he started out as a pure realist, he came to believe that the observer must in some ...
	2022-03-30: Could The Universe Be Inside A Black Hole? 05:19: ... outside universe. So the black hole and the big bang singularities are starting to look more alike. With the difference being, their residence in the ... 06:28: That’s starting to look like our universe - a past, space-like singularity and an event horizon that can’t be crossed from the outside. 10:40: OK, so we need one last ingredient to be able to answer “maybe” to the question we started with: Are we in a black hole? 05:19: ... outside universe. So the black hole and the big bang singularities are starting to look more alike. With the difference being, their residence in the ... 06:28: That’s starting to look like our universe - a past, space-like singularity and an event horizon that can’t be crossed from the outside.
	2022-03-23: Where Is The Center of The Universe? 02:55: As with much, it starts with Einstein. 06:21: In the case of the closed universe, that means it started out as a very, very tiny hypersphere surface and got bigger. 09:40: ... - if all geodesics emerged from that point - does that mean the universe started out ... 10:16: So did the universe start out pointlike at t=0 and then suddenly become infinite in size? 14:27: ... starts out explaining relativity in terms of boats passing by each other on a ... 14:58: Starting with Proxima. 15:27: But even if life didn’t start in tidal pools on Earth, who’s to say it couldn’t have happened that way elsewhere? 16:11: A hot interior may also have been essential for abiogenesis - if life really did first start around geothermal vents or hot springs. 06:21: In the case of the closed universe, that means it started out as a very, very tiny hypersphere surface and got bigger. 09:40: ... - if all geodesics emerged from that point - does that mean the universe started out ... 14:58: Starting with Proxima. 02:55: As with much, it starts with Einstein. 14:27: ... starts out explaining relativity in terms of boats passing by each other on a ...
	2022-03-16: What If Charge is NOT Fundamental? 03:23: By introducing this new conserved quantity,  Heisenberg started to make  sense of the relationship between protons and neutrons. 08:03: Starting with experiments at the Stanford Linear Accelerator Center in 1968, the reality of quarks quickly became conclusive. 09:32: ... to connect all of this back to quantum spin, which is sort of where we started. ... 03:23: By introducing this new conserved quantity,  Heisenberg started to make  sense of the relationship between protons and neutrons. 09:32: ... to connect all of this back to quantum spin, which is sort of where we started. ... 08:03: Starting with experiments at the Stanford Linear Accelerator Center in 1968, the reality of quarks quickly became conclusive.
	2022-03-08: Is the Proxima System Our Best Hope For Another Earth? 00:46: ... Almagest,   more than a millennium and a half passed before we started to realize its incredible ... 02:00: Dreams of an interstellar humanity started with the twins at the centaur’s foot. 16:27: ... it’s yours to do with it as you wish - name it, claim lordship over it, start your galactic empire there, or just use it for weekend ... 00:46: ... Almagest,   more than a millennium and a half passed before we started to realize its incredible ... 02:00: Dreams of an interstellar humanity started with the twins at the centaur’s foot.
	2022-02-23: Are Cosmic Strings Cracks in the Universe? 00:00: ... from a single surface. If the crystallization  process starts from multiple nucleation points   then there’ll be ... 04:51: ... Here and there across   the universe, the Higgs field started falling  towards the new vacuum state - we call this ... 08:50: ... these things are long. They started as long  as light can travel between the nucleation ... 04:51: ... Here and there across   the universe, the Higgs field started falling  towards the new vacuum state - we call this ... 08:50: ... these things are long. They started as long  as light can travel between the nucleation ... 04:51: ... Here and there across   the universe, the Higgs field started falling  towards the new vacuum state - we call this vacuum   decay. ... 10:09: ... do. Now, how do we  find them, assuming they exist? Well let’s start   with these gravitational waves. That radiation  should be emitted ... 00:00: ... from a single surface. If the crystallization  process starts from multiple nucleation points   then there’ll be ...
	2022-02-16: Is The Wave Function The Building Block of Reality? 04:17: ... story starts in 1986 when three Italian physicists, Giancarlo Ghirardi, Alberto ...
	2022-02-10: The Nature of Space and Time AMA 00:03: ... the day is the nature of space and the nature of time now i should start out by pointing out that no one knows what the nature of space and ...
	2022-01-27: How Does Gravity Escape A Black Hole? 03:25: Starting with good old fashioned general relativity. 13:25: Starting with the quantum, manonthedollar asks - given the incredible amount of power required to simulate quantum interactions... 14:21: We said that in density function theory you start with a make-believe system of non-interacting electrons. 03:25: Starting with good old fashioned general relativity. 13:25: Starting with the quantum, manonthedollar asks - given the incredible amount of power required to simulate quantum interactions...
	2022-01-19: How To Build The Universe in a Computer 02:04: ... the simulation went like this: Holmberg started with a pair of these light-bulb-galaxies next to each other, with the ... 02:33: Then, from that new configuration he’d start the process again. 06:16: It works like this: you start with a volume full of particles, each with its starting position and velocity. 07:52: The universe started as an ocean of gas a few hundred thousand years after the Big Bang. 09:34: ... don’t get me started about the complexity  of including magnetic fields, or of ... 02:04: ... the simulation went like this: Holmberg started with a pair of these light-bulb-galaxies next to each other, with the ... 07:52: The universe started as an ocean of gas a few hundred thousand years after the Big Bang. 09:34: ... don’t get me started about the complexity  of including magnetic fields, or of ... 06:16: It works like this: you start with a volume full of particles, each with its starting position and velocity.
	2022-01-12: How To Simulate The Universe With DFT 02:39: But it’s where we start learning quantum mechanics, and it works for a lot of simple cases. 05:52: ... the impossible case of many interacting quantum particles, we should start by thinking about the completely solvable case of many non-quantum or ... 10:42: ... we start with a bad guess at the ground state charge distribution and then ... 11:37: ... according to the theorem that we started with, that ground state charge distribution is unique - it corresponds ... 02:39: But it’s where we start learning quantum mechanics, and it works for a lot of simple cases. 11:37: ... according to the theorem that we started with, that ground state charge distribution is unique - it corresponds ...
	2021-12-29: How to Find ALIEN Dyson Spheres 04:54: Surveys started to find many, many objects that fit the description. 10:28: The team started by looking for stars that were a little too faint for their visible-light color - below the main sequence. 13:31: But some very serious scientists - starting with Freeman Dyson and Carl Sagan - take the question very seriously. 04:54: Surveys started to find many, many objects that fit the description. 10:28: The team started by looking for stars that were a little too faint for their visible-light color - below the main sequence. 13:31: But some very serious scientists - starting with Freeman Dyson and Carl Sagan - take the question very seriously.
	2021-12-20: What Happens If A Black Hole Hits Earth? 06:35: ... black hole’s intense gravity. Try to feed a black hole too fast and it starts to blast away its own food. The bigger the black hole the faster it can ... 00:29: ... holes to pass through our solar system - and even the planet - with startling frequency. In fact it may have already ... 06:35: ... black hole’s intense gravity. Try to feed a black hole too fast and it starts to blast away its own food. The bigger the black hole the faster it can ...
	2021-12-10: 2021 End of Year AMA! 00:02: ... we're gonna spend about 30 minutes so without further ado i will get started first question uh let's start by making this all about me because ...
	2021-11-17: Are Black Holes Actually Fuzzballs? 05:09: ... gravity starts to get quantum even above the event horizon, then it may be possible to ... 06:12: Lose that pesky infinite density and we can start making sense of physics again. 11:07: But if you approach the fuzzball you start to see this surface of stringy material with a thickness of about a Planck length. 14:10: ... starts out explaining relativity in terms of boats passing each other on a ... 06:12: Lose that pesky infinite density and we can start making sense of physics again. 05:09: ... gravity starts to get quantum even above the event horizon, then it may be possible to ... 14:10: ... starts out explaining relativity in terms of boats passing each other on a ...
	2021-11-10: What If Our Understanding of Gravity Is Wrong? 03:44: In MOND, force or acceleration drop off with distance squared until, at very low values they start to plateau out. 08:50: ... it was a good start - the resulting  “AQuaL - for “a quadratic Lagrangian” gave the ...
	2021-11-02: Is ACTION The Most Fundamental Property in Physics? 02:21: ... ball starts out moving fast - it has a lot of kinetic energy, which it trades for ... 05:52: ... start with Einstein’s General Theory of Relativity, which, as we’ve discussed ... 07:09: ... valid even in the shifting frames of Einstein’s relativity. And we also start to learn something about the nature of the Action. Once we apply the ... 08:39: ... start with the famous double slit experiment, as we so often do when talking ... 11:59: ... Dirac started to guess, particles tend to end up near the stationary points of the ... 13:46: ... remember, this all started with Heron of Alexandria studying light two thousand years ago. He found ... 15:27: ... that constructor theory really offers anything new. And honestly, I started out wondering the same and it took me a lot of time to get an inkling ... 11:59: ... Dirac started to guess, particles tend to end up near the stationary points of the ... 13:46: ... remember, this all started with Heron of Alexandria studying light two thousand years ago. He found ... 15:27: ... that constructor theory really offers anything new. And honestly, I started out wondering the same and it took me a lot of time to get an inkling ... 02:21: ... ball starts out moving fast - it has a lot of kinetic energy, which it trades for ...
	2021-10-20: Will Constructor Theory REWRITE Physics? 00:51: Based on some initial state - a starting set of these numbers predict how the system will evolve at all future times Step 4. 02:10: Some are starting to wonder if we need to rethink how we do physics at the fundamental level. 04:55: ... mechanistic philosophy that dominates physics really started with Isaac Newton, so it’s appropriate to start with the falling apple ... 14:00: ... a tunneling event be considered travel at   all. Does it just start existing on the other side  of the barrier without crossing the ... 14:48: ... These comments are telling me that you  lot are really starting to get a sense   of how far our perception of  reality is ... 14:00: ... a tunneling event be considered travel at   all. Does it just start existing on the other side  of the barrier without crossing the ... 04:55: ... mechanistic philosophy that dominates physics really started with Isaac Newton, so it’s appropriate to start with the falling apple ... 00:51: Based on some initial state - a starting set of these numbers predict how the system will evolve at all future times Step 4. 02:10: Some are starting to wonder if we need to rethink how we do physics at the fundamental level. 14:48: ... These comments are telling me that you  lot are really starting to get a sense   of how far our perception of  reality is ... 00:51: Based on some initial state - a starting set of these numbers predict how the system will evolve at all future times Step 4.
	2021-10-13: New Results in Quantum Tunneling vs. The Speed of Light 05:48: If the position of the tunneling particle isn’t perfectly known, how do we know when to start and stop our tunneling stopwatch? 05:56: It seems natural to define those times as whenever the center of the wavefunction passes the start and end points. 06:45: It’s hard to measure the travel time of a quantum train OR a quantum wavefunction because it’s hard to define the start and end points. 07:01: Launch a particle through empty space with a well defined starting position, and it’s position wavefunction will spread out before the finish line. 13:06: ... starts out explaining relativity in terms of boats passing by each other on a ... 07:01: Launch a particle through empty space with a well defined starting position, and it’s position wavefunction will spread out before the finish line. 13:06: ... starts out explaining relativity in terms of boats passing by each other on a ...
	2021-10-05: Why Magnetic Monopoles SHOULD Exist 06:00: ... you start with a dipole magnetic field, you can approximate a monopole by moving ...
	2021-09-21: How Electron Spin Makes Matter Possible 00:26: ... to turn an electron around twice - 720 degrees - to get it back to its starting position. They are, we say, spin-½ - because one normal rotation only ... 01:13: ... the much more sensible case of a single 360 degrees rotation back to the starting point. Integer-spin particles are bosons, and they are the force ... 02:59: ... that fermions have, and has this property that it returns to its starting state with a 720 degree rotation, not ... 06:49: ... 360 degree rotation puts a spinor perfectly out of phase compared to its starting point. So a 360 rotation introduces a negative sign to the spinor ... 00:26: ... to turn an electron around twice - 720 degrees - to get it back to its starting position. They are, we say, spin-½ - because one normal rotation only ... 01:13: ... the much more sensible case of a single 360 degrees rotation back to the starting point. Integer-spin particles are bosons, and they are the force ... 02:59: ... that fermions have, and has this property that it returns to its starting state with a 720 degree rotation, not ... 06:49: ... 360 degree rotation puts a spinor perfectly out of phase compared to its starting point. So a 360 rotation introduces a negative sign to the spinor ... 01:13: ... the much more sensible case of a single 360 degrees rotation back to the starting point. Integer-spin particles are bosons, and they are the force carrying ... 06:49: ... 360 degree rotation puts a spinor perfectly out of phase compared to its starting point. So a 360 rotation introduces a negative sign to the spinor ... 01:13: ... the much more sensible case of a single 360 degrees rotation back to the starting point. Integer-spin particles are bosons, and they are the force carrying particles like ... 00:26: ... to turn an electron around twice - 720 degrees - to get it back to its starting position. They are, we say, spin-½ - because one normal rotation only gets you ... 02:59: ... that fermions have, and has this property that it returns to its starting state with a 720 degree rotation, not ...
	2021-09-15: Neutron Stars: The Most Extreme Objects in the Universe 02:35: ... Similar to Earth’s atmosphere,   this layer of haze starts out  very tenuous - almost a vacuum,   and then gets ... 04:04: ... we start to encounter the first truly strange states of matter. See, the ... 05:48: ... the real journey can begin as we  start to tunnel into the star’s interior.   We enter the outer crust ... 07:43: ... due to the electron capture process.   In fact the neutron gas starts to take over the role of the electrons. Neutrons are also ... 08:15: ... down the nuclei themselves  start to get fuzzy as protons are   outnumbered by neutrons 5 to 1. ... 12:23: ... of the  neutron star and even the protons and   neutrons start to lose structure and mush  together. This is all highly ... 05:48: ... high enough to drive some very exotic nuclear reactions. Electrons start to   be driven into the iron nuclei in a process called electron ... 13:06: ... above us on   the surface. It seems our neutron star has started accreting matter from a binary partner star.   Its mass is growing and ... 07:06: ... for the inner crust, our nuclei become so neutron-rich that they start   to fall apart. We call this “neutron drip” -  neutrons leak from ... 02:35: ... Similar to Earth’s atmosphere,   this layer of haze starts out  very tenuous - almost a vacuum,   and then gets ... 07:43: ... due to the electron capture process.   In fact the neutron gas starts to take over the role of the electrons. Neutrons are also ... 02:35: ... Similar to Earth’s atmosphere,   this layer of haze starts out  very tenuous - almost a vacuum,   and then gets denser as we ...
	2021-09-07: First Detection of Light from Behind a Black Hole 04:57: This gas starts to glow in a different way - not from heat, but from the motion of electrons between their atomic energy levels. 09:23: OK, it’s time we got back to the discovery that started our little journey - the light that was detected from behind a black hole. 11:47: After decades of practice, and inventing better and better telescopes, we’re starting to get good at this game. 09:23: OK, it’s time we got back to the discovery that started our little journey - the light that was detected from behind a black hole. 11:47: After decades of practice, and inventing better and better telescopes, we’re starting to get good at this game. 04:57: This gas starts to glow in a different way - not from heat, but from the motion of electrons between their atomic energy levels.
	2021-08-18: How Vacuum Decay Would Destroy The Universe 04:00: ... that's where the trouble starts. The Higgs field may have yet another weird property.   It ... 07:01: ... phase transition to water vapor - that   phase transition also starts in small bubbles that grow into its surroundings. The formation ... 11:34: ... or sufficiently large universe then vacuum decay has definitely started somewhere.   But as long as we’re far enough away we’re ... 04:00: ... that's where the trouble starts. The Higgs field may have yet another weird property.   It ... 07:01: ... phase transition to water vapor - that   phase transition also starts in small bubbles that grow into its surroundings. The formation ... 11:34: ... as long as we’re far enough away we’re safe. If the vacuum decay starts beyond several billion   light years, the accelerating ...
	2021-08-10: How to Communicate Across the Quantum Multiverse 09:23: ... he was only getting started. He follows up by finding a way to write one non-linear Schrodinger ... 17:12: ... I started that episode with a mangled quote - scientific progress is accompanied ... 09:23: ... he was only getting started. He follows up by finding a way to write one non-linear Schrodinger ... 17:12: ... I started that episode with a mangled quote - scientific progress is accompanied ...
	2021-08-03: How An Extreme New Star Could Change All Cosmology 06:21: ... collapse is the fact that if it got any smaller, its electrons would start to overlap - they’d have to occupy the same energy states. But that’s ... 09:51: ... like this could well produce the sort of turbulent motion to jump start a dynamo powerful enough to produce the observed magnetic ... 12:50: ... into protons, which would turn those protons into neutrons. If that starts to happen then you get a chain reaction of so-called electron capture ...
	2021-07-21: How Magnetism Shapes The Universe 00:02: As far as the north magnetic pole, where the needle starts spinning wildly? 09:10: These amplify what starts out as a very weak and disordered field into the ordered and powerful field that surrounds the Earth. 00:02: As far as the north magnetic pole, where the needle starts spinning wildly? 09:10: These amplify what starts out as a very weak and disordered field into the ordered and powerful field that surrounds the Earth. 00:02: As far as the north magnetic pole, where the needle starts spinning wildly?
	2021-07-13: Where Are The Worlds In Many Worlds? 10:38: And, I don’t know, maybe next to the love of your life, who convinces you to leave research and start a small bed and breakfast in Argentina.
	2021-07-07: Electrons DO NOT Spin 00:47: ... thread and switch on a vertical magnetic field. The cylinder immediately starts rotating with a constant speed. At first glance this appears to violate ... 08:50: ... familiar  objects, a rotation of 360 degrees gets it back to its starting point. That’s also true of vectors - which are just arrows pointing in ... 09:30: ... If we rotate the cube by 360 degrees, the cube itself is back to the starting point, but the ribbons have a twist compared to how they started.  ... 09:59: ... angle - and a 360 rotation pulls it out of  phase compared to its starting ... 16:27: ... point, asking if  the conditions of the Big Bang meant everything started out entangled. You’d think so - but  that’s not necessarily the ... 17:20: In other words, the universe - or our patch of it - may have started out unentangled and at low entropy, even if it was at thermal equilibrium. 16:27: ... point, asking if  the conditions of the Big Bang meant everything started out entangled. You’d think so - but  that’s not necessarily the ... 17:20: In other words, the universe - or our patch of it - may have started out unentangled and at low entropy, even if it was at thermal equilibrium. 09:30: ... to the starting point, but the ribbons have a twist compared to how they started.  Amazingly, if we rotate another 360 - not backwards but in the same ... 08:50: ... familiar  objects, a rotation of 360 degrees gets it back to its starting point. That’s also true of vectors - which are just arrows pointing in ... 09:30: ... If we rotate the cube by 360 degrees, the cube itself is back to the starting point, but the ribbons have a twist compared to how they started.  ... 09:59: ... angle - and a 360 rotation pulls it out of  phase compared to its starting ... 08:50: ... familiar  objects, a rotation of 360 degrees gets it back to its starting point. That’s also true of vectors - which are just arrows pointing in some ... 09:30: ... If we rotate the cube by 360 degrees, the cube itself is back to the starting point, but the ribbons have a twist compared to how they started.  ... 09:59: ... angle - and a 360 rotation pulls it out of  phase compared to its starting point. ... 08:50: ... you need to  rotate it twice - or 720 degrees - to get back to its starting state. ... 00:47: ... thread and switch on a vertical magnetic field. The cylinder immediately starts rotating with a constant speed. At first glance this appears to violate ...
	2021-06-23: How Quantum Entanglement Creates Entropy 02:48: ... the more common configurations. Hence, entropy increases. Here we can start to see the connection between entropy and information.   ... 04:50: ... As the (perhaps apocryphal) origin story goes, he only started calling his invention “entropy”   after talking to the great ...
	2021-06-16: Can Space Be Infinitely Divided? 03:14: ... start, let’s say you’re trying to measure the distance to an object. You ... 06:02: ... and momentum. As we crank up the energy   even further we start to notice something. The photon is starting to produce an ...
	2021-06-09: Are We Running Out of Space Above Earth? 12:47: Or we could start taking more care right now. 14:49: ... within that range then perhaps it would be absorbed and the relic would start to ...
	2021-05-25: What If (Tiny) Black Holes Are Everywhere? 05:45: But as the black hole gets very small, the allowed vibrational modes start to get restricted. 07:04: ... let me start by saying that we know for sure that general relativity doesn’t work on ...
	2021-05-19: Breaking The Heisenberg Uncertainty Principle 00:47: ... measurements have become so precise that we’re starting to run up against the absolute quantum limit - the limit defined by the ...
	2021-05-11: How To Know If It's Aliens 01:55: ... start - or rather continue with our quest to find evidence of primitive life ...
	2021-04-21: The NEW Warp Drive Possibilities 06:44: We’ll start with the paper entitled Introducing Physical Warp Drives by Alexey Bobrick and Gianni Martire. 07:16: All of them, including Alcubierre’s, move with whatever velocity they started at. 08:02: A superluminal warp bubble has to have started out superluminal. 14:04: We’ll start with the muon g-2 result, which revealed a possible a crack in the standard model of particle physics. 07:16: All of them, including Alcubierre’s, move with whatever velocity they started at. 08:02: A superluminal warp bubble has to have started out superluminal.
	2021-04-13: What If Dark Matter Is Just Black Holes? 03:06: ... before we start eliminating specific black holes masses, let’s rule out an entire class ... 05:36: OK, let’s get started. 03:06: ... before we start eliminating specific black holes masses, let’s rule out an entire class of black ... 05:36: OK, let’s get started.
	2021-04-07: Why the Muon g-2 Results Are So Exciting! 02:44: Starting in 20 years ago, experimental measurements of the Muon g-factor did not agree with the QED calculation. 03:01: Let's start by talking about quantum spin. 02:44: Starting in 20 years ago, experimental measurements of the Muon g-factor did not agree with the QED calculation.
	2021-03-23: Zeno's Paradox & The Quantum Zeno Effect 02:04: In this case let’s say our quantum arrow’s position is quantized - it can exist only at the start and end of its path, but not in between. 02:13: In order to travel from start to end, it has to flick between these states without occupying intervening space. 02:32: That means it can be at the start and end of its path simultaneously. 02:58: ... amplitudes of its position; its wavefunction is spread between the start and end of the ... 03:36: ... begins in the pure state of being entirely at the start of its journey, but then it enters a superposition of states - mostly at ... 03:47: ... you observe the arrow now, most likely it’ll “collapse” to the starting position, but there’s a small chance it would suddenly appear at the ... 03:58: ... no observation the wavefunction evolves - less and less amplitude at the starting state and more and more at the end state - until it finally enters the ... 04:28: Every observation you make of the arrow collapses its wavefunction into one of its possible positions - start or end. 04:34: But because you start watching it close to the beginning of its journey, there’s very little probability of it collapsing to the end. 04:41: ... observation resets the trajectory to the start, at which point the wavefunction has to start evolving from scratch - but ... 07:15: To test this, the researchers start the atoms all in state one, and then hit them with a series of very rapid laser pulses. 08:54: Let’s start with measurement. 09:11: ... a way that the electron had an increased chance to jiggle back to its starting ... 10:32: In fact, as argued by Ballentine, you can force a quantum system back to its starting state without true decoherence. 11:18: But in this case, you’re not forcing the wavefunction to collapse back to its starting position through the power of observation. 11:42: If you do it right you’ll produce more “worlds” in which the system goes back to its starting state. 11:48: And then you enter the world of of the possible outcome states - again, most likely the starting position. 11:54: But if your observation wasn’t perfect, there’ll be some worlds in which the final state is chosen rather than the starting state. 13:13: To learn more, check out TheGreatCoursesPlus.com/spacetimepbs or click on the link in the description below to start your trial today. 15:56: I said at the start of the episode that it's exciting for scientists to be proven wrong. 04:41: ... the trajectory to the start, at which point the wavefunction has to start evolving from scratch - but you keep observing it and keep resetting it back ... 04:34: But because you start watching it close to the beginning of its journey, there’s very little probability of it collapsing to the end. 03:47: ... you observe the arrow now, most likely it’ll “collapse” to the starting position, but there’s a small chance it would suddenly appear at the ... 03:58: ... no observation the wavefunction evolves - less and less amplitude at the starting state and more and more at the end state - until it finally enters the ... 09:11: ... a way that the electron had an increased chance to jiggle back to its starting ... 10:32: In fact, as argued by Ballentine, you can force a quantum system back to its starting state without true decoherence. 11:18: But in this case, you’re not forcing the wavefunction to collapse back to its starting position through the power of observation. 11:42: If you do it right you’ll produce more “worlds” in which the system goes back to its starting state. 11:48: And then you enter the world of of the possible outcome states - again, most likely the starting position. 11:54: But if your observation wasn’t perfect, there’ll be some worlds in which the final state is chosen rather than the starting state. 09:11: ... a way that the electron had an increased chance to jiggle back to its starting location. ... 03:47: ... you observe the arrow now, most likely it’ll “collapse” to the starting position, but there’s a small chance it would suddenly appear at the final state - ... 11:18: But in this case, you’re not forcing the wavefunction to collapse back to its starting position through the power of observation. 11:48: And then you enter the world of of the possible outcome states - again, most likely the starting position. 03:58: ... no observation the wavefunction evolves - less and less amplitude at the starting state and more and more at the end state - until it finally enters the pure ... 10:32: In fact, as argued by Ballentine, you can force a quantum system back to its starting state without true decoherence. 11:42: If you do it right you’ll produce more “worlds” in which the system goes back to its starting state. 11:54: But if your observation wasn’t perfect, there’ll be some worlds in which the final state is chosen rather than the starting state.
	2021-03-16: The NEW Crisis in Cosmology 00:22: ... be   wrong. So it’s no wonder that many cosmologists are starting to get excited by what has become   known as the Hubble ... 08:03: ... that are close enough for   parallax measurements. Things started to get better when we put telescopes in space - above   ... 09:50: ... we start jumping up and  down and yelling about new physics,   ... 08:03: ... that are close enough for   parallax measurements. Things started to get better when we put telescopes in space - above   ... 00:22: ... be   wrong. So it’s no wonder that many cosmologists are starting to get excited by what has become   known as the Hubble ...
	2021-03-09: How Does Gravity Affect Light? 02:09: In general relativity, the best place to start is always the equivalence principle. 05:13: Let’s start with the good-old equivalence principle again, and a spaceship attacked by giant alien spiders.
	2021-02-24: Does Time Cause Gravity? 01:48: Let’s start with … a teapot. 01:56: Absent a gravitational field or any forces, if the teapot starts motionless it stays that way. 04:47: All individual 4-velocities start out being purely in time, but the sum is rotated partially into space. 01:56: Absent a gravitational field or any forces, if the teapot starts motionless it stays that way.
	2021-02-10: How Does Gravity Warp the Flow of Time? 01:13: Einstein had his happy thought in 1907, a couple of years after he started his scientific revolution with the special theory of relativity. 03:07: ... going to start out by me totally convincing you that time must run slow in a ... 01:13: Einstein had his happy thought in 1907, a couple of years after he started his scientific revolution with the special theory of relativity.
	2021-01-19: Can We Break the Universe? 00:09: ... back in 1905, when Einstein was just getting started - he was already rocking our understanding of the universe with his ... 00:17: ... theory started with the simple assumption that the speed of light was the fastest speed ... 02:33: ... back on itself, so by traveling far enough you can get back to where you started. ... 03:21: Let’s start with the twin paradox. 09:04: If the ladder didn’t fit in the barn to start with, it most certainly doesn’t fit now. 10:03: ... spatial direction - initially longer than the barn, but when the ladder starts moving it shortens so that it neatly fits inside the barn before ... 13:17: We'll start with the latter. 00:09: ... back in 1905, when Einstein was just getting started - he was already rocking our understanding of the universe with his ... 00:17: ... theory started with the simple assumption that the speed of light was the fastest speed ... 02:33: ... back on itself, so by traveling far enough you can get back to where you started. ... 00:09: ... back in 1905, when Einstein was just getting started - he was already rocking our understanding of the universe with his ... 10:03: ... spatial direction - initially longer than the barn, but when the ladder starts moving it shortens so that it neatly fits inside the barn before ...
	2021-01-12: What Happens During a Quantum Jump? 01:12: ... all started back in 1913, when the great Danish physicist Niels Bohr set about to ... 07:52: Then, after a period of time, the electron decays and fluorescence starts again. 10:02: But just prior to each jump the system started to shift in a way that enabled the researchers to predict the oncoming jump. 12:06: ... a century after Bohr and Schrodinger started the argument, we may be on the verge of the next quantum leap - to ... 01:12: ... all started back in 1913, when the great Danish physicist Niels Bohr set about to ... 10:02: But just prior to each jump the system started to shift in a way that enabled the researchers to predict the oncoming jump. 12:06: ... a century after Bohr and Schrodinger started the argument, we may be on the verge of the next quantum leap - to ... 07:52: Then, after a period of time, the electron decays and fluorescence starts again.
	2020-12-22: Navigating with Quantum Entanglement 15:57: Easy, start by imagining 10^31998 years and then do THAT 10 times.
	2020-12-15: The Supernova At The End of Time 01:24: Let’s actually start our story at the end. 06:39: Not a bad start to graduate school - showing up on your professor’s doorstep having already improved one of your prof’s major life achievements. 06:54: They start out hot and bright, but with no capacity to generate new energy, they slowly radiate away the heat of their youth.
	2020-12-08: Why Do You Remember The Past But Not The Future? 07:18: It’s fully formed but hasn’t started to decay yet. 09:54: ... universe started in a state of extremely low entropy - spatially separated regions were ... 10:53: ... in one direction and not the other is because the early universe started out with this incredibly rich resource of correlation-lite states, which ... 07:18: It’s fully formed but hasn’t started to decay yet. 09:54: ... universe started in a state of extremely low entropy - spatially separated regions were ... 10:53: ... in one direction and not the other is because the early universe started out with this incredibly rich resource of correlation-lite states, which ...
	2020-11-18: The Arrow of Time and How to Reverse It 04:13: ... if you start from a situation where energy is not perfectly randomly spread out, then ... 05:10: ... start with a handful of particles with low entropy. You can do low entropy by ... 06:19: ... if you live on either side of the starting, low-entropy point, you perceive an asymmetry in time - particles ... 04:13: ... entropy must increase over time - which just means that a system that starts out in a very specific, non-random state will tend to become more ...
	2020-11-11: Can Free Will be Saved in a Deterministic Universe? 03:21: These may transform and become entangled with each other, but if quantum information is conserved, a thread can never vanish nor start out of nothing. 05:28: Let's start with one and two. 06:21: Think about a new thread of quantum information starting from nothing, let's say emerging from a packet of space time where no information enters.
	2020-11-04: Electroweak Theory and the Origin of the Fundamental Forces 00:57: Let’s start with the mysterious and often misunderstood weak interaction. 10:13: However, if we cool the material down, the interactions between magnetic particles can start to come into play. 14:51: ... showed that at least some light rays - null geodesics - that start parallel from any trapped surface must converge in any positively curved ... 15:24: Start at Specialist Relativity and work your way up. 14:51: ... showed that at least some light rays - null geodesics - that start parallel from any trapped surface must converge in any positively curved ...
	2020-10-27: How The Penrose Singularity Theorem Predicts The End of Space Time 07:05: ... extending one of those paths just a little. The distance from the starting point   to the end of that extension is still the  same ... 10:36: ... beyond this point - which suggested that time really started at the Big Bang. Hawking and   Penrose further developed these ... 08:11: ... you reached the end   of north - maxed your northness - and started traveling south again. Well, in a black hole you   don’t reach the end ... 07:05: ... extending one of those paths just a little. The distance from the starting point   to the end of that extension is still the  same ...
	2020-10-20: Is The Future Predetermined By Quantum Mechanics? 05:39: Let's start with Copenhagen.
	2020-10-13: Do the Past and Future Exist? 00:22: ... we’re starting a deep dive into the nature of time - and down that rabbit hole we’ll ... 08:44: Start moving forward and your slice of “now” will skew. 00:22: ... we’re starting a deep dive into the nature of time - and down that rabbit hole we’ll ...
	2020-09-28: Solving Quantum Cryptography 03:23: Let’s start with a more visual example.
	2020-09-08: The Truth About Beauty in Physics 13:42: In fact let's start with the stars. 15:22: The Belle II experiment that just started taking data on Japan's superKEKB electron-positron collider.
	2020-09-01: How Do We Know What Stars Are Made Of? 00:39: A hundred years ago, we were starting to plumb the deepest mysteries of the universe with Einstein’s relativity and with quantum theory. 07:00: ... long before Celilia Payne started her research, Indian astrophysicist Meghdad Saha had used early ideas in ... 00:39: A hundred years ago, we were starting to plumb the deepest mysteries of the universe with Einstein’s relativity and with quantum theory.
	2020-08-24: Can Future Colliders Break the Standard Model? 03:40: Graduating from electrons and positrons, in 1971 physicists started smashing protons together at CERN’s Intersecting Storage Rings facility. 07:57: Let’s start with better before we move to bigger. 09:11: ... the FCC will be smashing protons like the LHC does, but to start with it’ll collide electrons and positrons with the express intention of ... 11:34: ... if it does happen it’ll be at Brookhaven National Labs on Long Island, starting in around 10 ... 15:16: They start separate, and the event horizons move towards each other as they join, and at some point the event horizons touch and then merge. 03:40: Graduating from electrons and positrons, in 1971 physicists started smashing protons together at CERN’s Intersecting Storage Rings facility. 11:34: ... if it does happen it’ll be at Brookhaven National Labs on Long Island, starting in around 10 ...
	2020-08-17: How Stars Destroy Each Other 04:13: After which they start the whole process all over again. 07:09: ... start, you need to know that when you look at our galaxy in gamma rays - the ... 08:10: In this case the companion didn’t start out as a brown dwarf - it became one after losing most of its mass to its ravenous partner. 10:25: As you know, at the start of the pandemic we all had to quarantine on Earth to avoid contaminating space with the virus.
	2020-08-10: Theory of Everything Controversies: Livestream 00:00: ... had james beach and stefan alexander and i think we really you know started to converge on on some some useful thoughts uh i really encourage you ...
	2020-07-28: What is a Theory of Everything: Livestream 00:00: ... nature and the inner workings of the universe and be a really good starting point perhaps to kick off many more great discussions uh this year in ...
	2020-07-20: The Boundary Between Black Holes & Neutron Stars 03:04: Unfortunately, there are countless galaxies in a region that size, so to start with we have no idea in which galaxy the merger happened.
	2020-07-08: Does Antimatter Explain Why There's Something Rather Than Nothing? 01:25: ... most likely answer seems to be that the universe started out with a little more matter compared to anti-matter. If there were ...
	2020-06-30: Dissolving an Event Horizon 07:42: By the time the gas reaches the black hole it has lost much of the angular momentum it started with. 12:25: ... a 3-D space, but travel around the tube and you’d get back to where you started. ... 07:42: By the time the gas reaches the black hole it has lost much of the angular momentum it started with. 12:25: ... a 3-D space, but travel around the tube and you’d get back to where you started. ...
	2020-06-22: Building Black Holes in a Lab 01:29: ... it turns out we don’t need to make a real black hole to at least get started with the lab work. We can instead study analog black holes - and by ... 01:54: ... whole idea of analog black holes was started in 1972 by Bill Unruh - most known for his Unruh radiation, which we’ve ... 01:29: ... it turns out we don’t need to make a real black hole to at least get started with the lab work. We can instead study analog black holes - and by ... 01:54: ... whole idea of analog black holes was started in 1972 by Bill Unruh - most known for his Unruh radiation, which we’ve ...
	2020-06-15: What Happens After the Universe Ends? 11:39: If entropy can only rise over time, per the second law of thermodynamics, how did it get so low at the start?
	2020-06-08: Can Viruses Travel Between Planets? 01:08: I’m going to start with this absolute statement, because you know how the internet can be.
	2020-05-18: Mapping the Multiverse 00:09: ... can be traced out again but you do not end up in the universe that you started ... 04:06: But now as we fall the outward pressure due to the black hole’s rotation starts to win against that inward flow. 05:53: ... field is according to the geodesics of objects in freefall that start motionless relative to the gravitational ... 08:13: There are trajectories in this torus that lead you back to your starting location - in both space AND time. 10:37: ... universe either - here, the laws of physics are the same as where you started - at least as far as general relativity is ... 05:53: ... field is according to the geodesics of objects in freefall that start motionless relative to the gravitational ... 00:09: ... can be traced out again but you do not end up in the universe that you started ... 10:37: ... universe either - here, the laws of physics are the same as where you started - at least as far as general relativity is ... 08:13: There are trajectories in this torus that lead you back to your starting location - in both space AND time. 04:06: But now as we fall the outward pressure due to the black hole’s rotation starts to win against that inward flow.
	2020-05-11: How Luminiferous Aether Led to Relativity 09:26: ... say you set up the interferometer and see your interference pattern. To start with you wouldn’t know whether the arms were exactly equal lengths or ... 11:42: ... published 8 years after the Michelson-Morley experiment. Now Einstein’s starting motivation seems to have been the fact that the Maxwell equations are ... 13:18: ... his deathbed in 1931 Michelson's daughter begged Einstein “not get him started on the subject of the aether.” Michelson may have mourned the death of ... 14:06: ... is infinite in size" and "the universe has a finite age" if the universe started from a singularity. How do you go from infinitessimally small to ... 13:18: ... his deathbed in 1931 Michelson's daughter begged Einstein “not get him started on the subject of the aether.” Michelson may have mourned the death of ... 14:06: ... is infinite in size" and "the universe has a finite age" if the universe started from a singularity. How do you go from infinitessimally small to ... 11:42: ... published 8 years after the Michelson-Morley experiment. Now Einstein’s starting motivation seems to have been the fact that the Maxwell equations are ...
	2020-05-04: How We Know The Universe is Ancient 11:07: ... discovered the anti-gravitational effect of dark energy, and had to start adding that into their equations also. But that’s a story for another ...
	2020-04-28: Space Time Livestream: Ask Matt Anything 00:00: ... lots of types of questions we could we could go through I'm gonna just start by talking about the show and we'll get into some science and we'll ...
	2020-04-14: Was the Milky Way a Quasar? 02:19: ... start in 2010, when a team of astronomers from the Harvard-Smithsonian Centre ... 05:59: Let’s start with “when” - it’s a bit more straightforward. 15:12: ... of the Universe state that, if it was created at all and didn't just start, as it were, unofficially, it came into being between ten and twenty ...
	2020-04-07: How We Know The Earth Is Ancient 01:48: ... his result in 1778. It was ingenious really. He assumed the Earth started as a ball of molten rock, which subsequently cooled down to its current ... 07:17: ... to decay. In principle, if you know how much of the stuff there was to start with you can figure out how long the radioactive material has been ... 09:33: ... can figure out how much uranium a given sample had to start with by looking at the proportion of uranium to lead. This only works if ... 11:02: ... back Earth’s age further and further. But beyond a few billion years it starts to get tricky. There aren’t many patches of land left from way back ... 01:48: ... his result in 1778. It was ingenious really. He assumed the Earth started as a ball of molten rock, which subsequently cooled down to its current ... 11:02: ... back Earth’s age further and further. But beyond a few billion years it starts to get tricky. There aren’t many patches of land left from way back ...
	2020-03-24: How Black Holes Spin Space Time 03:54: ... start by talking about what is actually rotating in a Kerr black hole. It’s ...
	2020-03-16: How Do Quantum States Manifest In The Classical World? 02:39: ... quantum darwinism - and you’ll see why. To get there we need to start by talking about quantum ... 04:28: ... superposition of states - measured in the vertical basis, each particle starts in a state of both up AND down, while in the horizontal each is left AND ... 07:37: ... so, we put this atom along the up path of our device, and we start it out in the off state. If our electron takes the up path it flips the ... 15:22: To learn more www.thegreatcoursesplus.com/spacetime or click on the link in the description to start your trial today. 04:28: ... superposition of states - measured in the vertical basis, each particle starts in a state of both up AND down, while in the horizontal each is left AND ...
	2020-03-03: Does Quantum Immortality Save Schrödinger's Cat? 08:03: So more likely near the middle of our species existence rather than right at the start or right at the end.
	2020-02-24: How Decoherence Splits The Quantum Multiverse 00:35: ... last week’s episode we started down this rabbit hole exploring the measurement problem - the question ... 13:47: In fact the details have been worked out with mathematical rigor - starting with H. Dieter Zeh’s foundational paper in 1970. 00:35: ... last week’s episode we started down this rabbit hole exploring the measurement problem - the question ... 13:47: In fact the details have been worked out with mathematical rigor - starting with H. Dieter Zeh’s foundational paper in 1970.
	2020-02-18: Does Consciousness Influence Quantum Mechanics? 01:32: ... start, we're going to need to go back to one of the earliest interpretations of ... 08:09: ... perhaps the first to assert the connection, and his influence may have started the development of the Copenhagen interpretation - later attributed ...
	2020-02-11: Are Axions Dark Matter? 15:20: ... Let's say 10^10^60-ish times the diameter of our universe until things start to repeat ...
	2020-02-03: Are there Infinite Versions of You? 01:08: To start with we need though we need some monkeys. 03:13: Perhaps you can start to see how this applies to there being infinite yous in an infinite universe. 03:19: ... a perfectly deterministic universe, the starting conditions in any given region - like positions, velocities, etc of all ... 05:24: If there are infinite possible starting configurations for any one region of the universe, then there can be infinite regions without any doubling up. 05:32: But if there are finite starting points then at least SOME of those starting configurations have to be repeated infinite times. 05:54: So if there really are finite possible starting conditions then this region is probably repeated. 06:02: So what does it mean for two regions of the universe to have the same starting conditions? 06:31: In such a chaotic system, even tiny differences in the starting conditions will lead to massive divergences in that future history. 06:39: ... there is an allowable level of ridiculously tiny deviation in the starting conditions between two regions that would still lead near-identical 13.5 ... 06:53: We can’t tune the starting conditions to an infinite degree and still get different results - and that’s the key point. 07:01: It seems there must be finite possible starting configurations. 07:12: I should also note that it’s not just the particles that define starting conditions, there’s also the laws of physics themselves. 08:40: For example, you could argue that fundamental quantum randomness will cause even identical starting configurations to produce different results. 09:00: In fact, quantum randomness could allow different starting conditions to evolve into a universe that looks like this one. 11:59: Honestly, I was dismissive of the idea before I started writing this script. 14:37: Well to start with, there is a causal order for the incoming and outgoing particles - the former cause the latter, and so they must come first. 11:59: Honestly, I was dismissive of the idea before I started writing this script. 03:19: ... a perfectly deterministic universe, the starting conditions in any given region - like positions, velocities, etc of all ... 05:24: If there are infinite possible starting configurations for any one region of the universe, then there can be infinite regions without any doubling up. 05:32: But if there are finite starting points then at least SOME of those starting configurations have to be repeated infinite times. 05:54: So if there really are finite possible starting conditions then this region is probably repeated. 06:02: So what does it mean for two regions of the universe to have the same starting conditions? 06:31: In such a chaotic system, even tiny differences in the starting conditions will lead to massive divergences in that future history. 06:39: ... there is an allowable level of ridiculously tiny deviation in the starting conditions between two regions that would still lead near-identical 13.5 ... 06:53: We can’t tune the starting conditions to an infinite degree and still get different results - and that’s the key point. 07:01: It seems there must be finite possible starting configurations. 07:12: I should also note that it’s not just the particles that define starting conditions, there’s also the laws of physics themselves. 08:40: For example, you could argue that fundamental quantum randomness will cause even identical starting configurations to produce different results. 09:00: In fact, quantum randomness could allow different starting conditions to evolve into a universe that looks like this one. 03:19: ... a perfectly deterministic universe, the starting conditions in any given region - like positions, velocities, etc of all particles - ... 05:54: So if there really are finite possible starting conditions then this region is probably repeated. 06:02: So what does it mean for two regions of the universe to have the same starting conditions? 06:31: In such a chaotic system, even tiny differences in the starting conditions will lead to massive divergences in that future history. 06:39: ... there is an allowable level of ridiculously tiny deviation in the starting conditions between two regions that would still lead near-identical 13.5 billion ... 06:53: We can’t tune the starting conditions to an infinite degree and still get different results - and that’s the key point. 07:12: I should also note that it’s not just the particles that define starting conditions, there’s also the laws of physics themselves. 09:00: In fact, quantum randomness could allow different starting conditions to evolve into a universe that looks like this one. 05:24: If there are infinite possible starting configurations for any one region of the universe, then there can be infinite regions without any doubling up. 05:32: But if there are finite starting points then at least SOME of those starting configurations have to be repeated infinite times. 07:01: It seems there must be finite possible starting configurations. 08:40: For example, you could argue that fundamental quantum randomness will cause even identical starting configurations to produce different results. 05:32: But if there are finite starting points then at least SOME of those starting configurations have to be repeated infinite times.
	2020-01-27: Hacking the Nature of Reality 01:30: ... it, insisting that matters are the observables - the measurable start and end points of an ... 03:10: But problems returned when we started to peer into the atomic nucleus. 09:11: ... up by the bootstraps” - the idea of raising yourself up without concrete starting point to push off ... 03:10: But problems returned when we started to peer into the atomic nucleus. 09:11: ... up by the bootstraps” - the idea of raising yourself up without concrete starting point to push off ... 06:04: At the time, nuclear scattering experiments were producing a startling variety of different particles.
	2020-01-20: Solving the Three Body Problem 01:24: ... Plug numbers into that equation and its solved. Those numbers are the starting positions and velocities of your gravitating bodies, plus a value for ... 03:18: ... reality of the three-body problem is that the evolution of almost all starting configurations is dominated by chaotic dynamics. Future states are ... 07:56: ... motion - they evolve - sometimes in complex ways - back to their starting configuration. In the 70s, Michel Henon and Roger Broucke found a family ... 15:31: ... we hadn’t met before we started filming, we are kindred spirits, interested both in cutting edge science ... 01:24: ... Plug numbers into that equation and its solved. Those numbers are the starting positions and velocities of your gravitating bodies, plus a value for ... 03:18: ... reality of the three-body problem is that the evolution of almost all starting configurations is dominated by chaotic dynamics. Future states are ... 07:56: ... motion - they evolve - sometimes in complex ways - back to their starting configuration. In the 70s, Michel Henon and Roger Broucke found a family ... 03:18: ... reality of the three-body problem is that the evolution of almost all starting configurations is dominated by chaotic dynamics. Future states are highly dependent on ... 01:24: ... Plug numbers into that equation and its solved. Those numbers are the starting positions and velocities of your gravitating bodies, plus a value for ...
	2020-01-13: How To Capture Black Holes 10:40: ... since LIGO started operation we now have advanced follow-up systems in place. As soon as a ...
	2019-12-17: Do Black Holes Create New Universes? 15:20: ... about the doomsday argument then chances are they didn't come near the start of their ...
	2019-12-09: The Doomsday Argument 05:07: And that’s the same guy who brought to popular attention and in fact named the anthropic principle to start with. 05:13: To start, let’s try a thought experiment. 13:39: ... start with a question from the discord: Habunelahack asks if it's ever be ...
	2019-12-02: Is The Universe Finite? 02:02: But more detailed study of the Planck data has started to reveal tensions. 03:19: Just like with the 2-D spherical analog, lines that start parallel in such a universe eventually come together. 03:32: If you travel far enough around you'll get back to where you started. 07:57: And can we find a faster route to India by traveling all the way around the cosmos to get back to where we started? 03:19: Just like with the 2-D spherical analog, lines that start parallel in such a universe eventually come together. 02:02: But more detailed study of the Planck data has started to reveal tensions. 03:32: If you travel far enough around you'll get back to where you started. 07:57: And can we find a faster route to India by traveling all the way around the cosmos to get back to where we started?
	2019-11-18: Can You Observe a Typical Universe? 00:00: The moment you started observing reality, you hopelessly polluted any conclusions you might make about it. 01:00: ... in the universe is called the Copernican principle after the guy who started it ... 09:46: If we then assume that the starting conditions for our universe were typical, that can tell us something about the physics of how universes are born. 00:00: The moment you started observing reality, you hopelessly polluted any conclusions you might make about it. 01:00: ... in the universe is called the Copernican principle after the guy who started it ... 00:00: The moment you started observing reality, you hopelessly polluted any conclusions you might make about it. 09:46: If we then assume that the starting conditions for our universe were typical, that can tell us something about the physics of how universes are born.
	2019-11-11: Does Life Need a Multiverse to Exist? 04:01: Let’s start with chemistry. 16:33: ... civilization, seems like such a huge responsibility that maybe we should start acting as though the stakes really are that high and not screw it all ... 16:59: Actually these just came in while I was writing the rare earth episode, as soon as I started thinking about how we're totally screwing it all up. 16:33: ... civilization, seems like such a huge responsibility that maybe we should start acting as though the stakes really are that high and not screw it all ... 16:59: Actually these just came in while I was writing the rare earth episode, as soon as I started thinking about how we're totally screwing it all up.
	2019-11-04: Why We Might Be Alone in the Universe 04:23: Actually, let’s start by something that is NOT rare about the Earth. 04:53: ... billions of potential starting points for life in the Milky Way alone, even if we restrict ourselves to ... 05:02: ... stewing for billions of years - if only one civilization had a tiny head start on us then it could have colonized the galaxy by ... 05:41: We’ll start by comparing planets of our solar system, because our ability to probe extra-solar planets is still in its infancy. 14:22: ... long cylinder that you can travel around to end up back where you started - in both time and ... 04:53: ... billions of potential starting points for life in the Milky Way alone, even if we restrict ourselves to ...
	2019-10-21: Is Time Travel Impossible? 07:26: This generates sub-lightspeed paths through spacetime that form closed loops, ending up back where they started in both space and time.
	2019-10-15: Loop Quantum Gravity Explained 06:07: ADM starts by defining this abstract space of spaces - 3-D spatial metrics, 3-D space slices cut out of 4-D spacetime.
	2019-09-30: How Many Universes Are There? 02:35: Let’s start with the first two, because these are basically our challenge question. 06:19: ... of the vacuum should be so low without being exactly zero given that it started out so ... 11:46: Let’s start by answering the extra credit question: how close to bubbles need to be in order to collide? 06:19: ... of the vacuum should be so low without being exactly zero given that it started out so ...
	2019-09-23: Is Pluto a Planet? 14:30: ... also starting a newsletter that's open to everyone to make sure you get notified when ...
	2019-09-16: Could We Terraform Mars? 09:42: ... cover the entire surface to about 30 meters – which is not enough to start a proper water cycle or have oceans, but there may be a lot more water ... 15:42: It started out with one small step for man and now the journey to Mars is right around the corner!
	2019-09-03: Is Earth's Magnetic Field Reversing? 03:48: Let’s start with a quick review of what the interior of the Earth look like. 05:55: For now, let’s say that we start with some weak dipole field. 06:21: As a result, the starting magnetic field gets wound up into rings around the axis of rotation – into a torus shape. 07:05: OK, so start with a weak dipole field and you get a strong one. 07:23: Once started, the field builds to maximum strength. 09:21: ... and when the field just glitches but ends up in the same direction it started we call it a geomagnetic ... 11:36: We’ll need to see a lot more disruption before we start to worry. 07:23: Once started, the field builds to maximum strength. 09:21: ... and when the field just glitches but ends up in the same direction it started we call it a geomagnetic ... 06:21: As a result, the starting magnetic field gets wound up into rings around the axis of rotation – into a torus shape.
	2019-08-26: How To Become an Astrophysicist + Challenge Question! 00:00: ... for our recent episodes on the eternally inflating universe Let me start by telling you about my own path. It was typical enough I started out ... 03:35: ... where I thought I might be able to stick with this gig. Oh And then I started making YouTube videos because God forbid I take it easy for a bit if ... 00:00: ... Let me start by telling you about my own path. It was typical enough I started out with a deep fascination in physics in understanding the nuts and ... 03:35: ... where I thought I might be able to stick with this gig. Oh And then I started making YouTube videos because God forbid I take it easy for a bit if ...
	2019-08-19: What Happened Before the Big Bang? 02:03: ... we probably should know more about the field that drives it. To start with, you need a particular type of field to cause inflation, something ... 05:07: But it wouldn't end as a random process, it wouldn't require quantum tunneling to get started. 09:18: And to get this started, you need a speck. 09:34: Assuming a quantum field of the right type and that speck will start inflating. 10:33: ... time start at the Big Bang" and "What caused the Big Bang, the real physics of ... 12:29: ... actually gives a physical reason for the universe to have started with a rapid outward expansion rate in terms of pretty well understood ... 12:50: Dominic H quips "Did time start at the Big Bang? Let me guess depends on your definitions of "Did", "Time", "Start" and "Big Bang" " Ah... 13:01: Bad science starts with bad questions. 09:34: Assuming a quantum field of the right type and that speck will start inflating. 05:07: But it wouldn't end as a random process, it wouldn't require quantum tunneling to get started. 09:18: And to get this started, you need a speck. 12:29: ... actually gives a physical reason for the universe to have started with a rapid outward expansion rate in terms of pretty well understood ... 13:01: Bad science starts with bad questions.
	2019-08-06: What Caused the Big Bang? 01:56: But physicists are a skeptical bunch and most of the time they don't just make up stories and start believing them without good reason. 08:51: ... a deeper truer minimum - perhaps the true vacuum state - and suddenly starts to lose energy again racing towards that ... 09:35: And just like a growing ice crystal, this effect will propagate outwards from the starting point, which we call a nucleation point, by analogy. 11:17: But, right from the start Guth admits a number of problems with his story. The big one is about how inflation stops. 12:41: If inflation happened at all, that it's hard to avoid two conclusions: Once started, inflation should continue... 12:49: eternally - Only stopping in patches where a bubble universe forms. And once started, inflation should produce infinite such universes. 01:56: But physicists are a skeptical bunch and most of the time they don't just make up stories and start believing them without good reason. 11:17: But, right from the start Guth admits a number of problems with his story. The big one is about how inflation stops. 12:41: If inflation happened at all, that it's hard to avoid two conclusions: Once started, inflation should continue... 12:49: eternally - Only stopping in patches where a bubble universe forms. And once started, inflation should produce infinite such universes. 12:41: If inflation happened at all, that it's hard to avoid two conclusions: Once started, inflation should continue... 12:49: eternally - Only stopping in patches where a bubble universe forms. And once started, inflation should produce infinite such universes. 09:35: And just like a growing ice crystal, this effect will propagate outwards from the starting point, which we call a nucleation point, by analogy. 08:51: ... a deeper truer minimum - perhaps the true vacuum state - and suddenly starts to lose energy again racing towards that ...
	2019-07-25: Deciphering The Vast Scale of the Universe 04:50: ... the discovery that the universe is expanding, meaning it must once have started with the Big ...
	2019-07-18: Did Time Start at the Big Bang? 00:00: Thank you to LastPass for sponsoring PBS Digital Studios Our universe started with the Big Bang. 00:05: But only for the right definition of our universe and "started" for that matter. In fact, the Big Bang is probably nothing like what you were taught. 00:25: ... small point - a singularity. It's often said that the universe started with this singularity and the Big Bang is thought of as the explosive ... 01:22: ... cooler, at least as far as we understand it Now, before a certain crowd starts with "all the scientists keep changing their minds - they don't know ... 07:22: ... at the Big Bang singularity and their timelines end with them Or they start depending on how you want to think about it The point is that in the ... 08:52: ... all space was compacted into a single point and that this is where Time started. Ok. So what are the ... 12:30: ... service options available. Click on the link in description below to start ... 07:22: ... at the Big Bang singularity and their timelines end with them Or they start depending on how you want to think about it The point is that in the pure ... 12:30: ... service options available. Click on the link in description below to start today ... 00:00: Thank you to LastPass for sponsoring PBS Digital Studios Our universe started with the Big Bang. 00:05: But only for the right definition of our universe and "started" for that matter. In fact, the Big Bang is probably nothing like what you were taught. 00:25: ... small point - a singularity. It's often said that the universe started with this singularity and the Big Bang is thought of as the explosive ... 08:52: ... all space was compacted into a single point and that this is where Time started. Ok. So what are the ... 01:22: ... cooler, at least as far as we understand it Now, before a certain crowd starts with "all the scientists keep changing their minds - they don't know ...
	2019-07-15: The Quantum Internet 01:21: ... Shannon started it all with his 1948 paper “A Mathematical Theory of Communication”, ... 07:50: ... qubit B, after which that qubit will be in the state qubit C was at the start. ... 01:21: ... Shannon started it all with his 1948 paper “A Mathematical Theory of Communication”, ...
	2019-06-17: How Black Holes Kill Galaxies 02:54: ... Star Busts as galaxies grew so did their Black Holes they would've started as a ready mass of seed Black Holes formed by the very first generation ... 13:30: ... to become protons and neutrons which means you are back to where you started ... 02:54: ... Star Busts as galaxies grew so did their Black Holes they would've started as a ready mass of seed Black Holes formed by the very first generation ... 13:30: ... to become protons and neutrons which means you are back to where you started ...
	2019-06-06: The Alchemy of Neutron Star Collisions 02:47: ... this neutrino wind to freedom our best calculations suggest that neutral start collisions should be much better than supernovae at producing heavy ... 13:02: ... the dark ages would have actually been dark at least to us the dark ages started following recombination and then the cosmic background would still have ... 02:47: ... this neutrino wind to freedom our best calculations suggest that neutral start collisions should be much better than supernovae at producing heavy elements and ... 13:02: ... the dark ages would have actually been dark at least to us the dark ages started following recombination and then the cosmic background would still have ...
	2019-05-16: The Cosmic Dark Ages 04:29: ... size. It expanded by a factor of 100 before the epoch of reionization started, and it’s expanded by a factor of 10 since ... 11:17: ... track the progress of reionization and even figure out when it must have started. ... 04:29: ... size. It expanded by a factor of 100 before the epoch of reionization started, and it’s expanded by a factor of 10 since ... 11:17: ... track the progress of reionization and even figure out when it must have started. ...
	2019-05-09: Why Quantum Computing Requires Quantum Cryptography 04:34: We’ll start with Heisenberg, which of course we’ve done an episode on already. 10:21: Man-in-the-middle attacks are in principle still possible because Werner could impersonate Albert and Niels from the very start.
	2019-05-01: The Real Science of the EHT Black Hole 04:16: You need a minimum of three telescopes to start to form an image.
	2019-04-24: No Dark Matter = Proof of Dark Matter? 00:03: ... into stars even without the dark matter that would normally be needed to start that process obviously more work is needed to understand these dark ...
	2019-04-10: The Holographic Universe Explained 01:07: We’ve made a background playlist if you want to start from scratch, and I especially recommend catching last week’s episode. 01:19: The story started with black holes, and with Jacob Bekenstein, who derived an equation to describe their entropy. 04:32: Let’s say we start with a plane – a flat, 2-D spacetime. 09:57: These are like multidimensional strings that can serve as start and end points for strings, but also as spaces embedded within higher-dimensions. 01:19: The story started with black holes, and with Jacob Bekenstein, who derived an equation to describe their entropy. 00:24: ... of the most startling possibilities is that our 3+1 dimensional universe may better described ... 12:29: But the more startling implication of AdS/CFT is that it’s the first concrete realization of a holographic universe. 00:24: ... of the most startling possibilities is that our 3+1 dimensional universe may better described ... 12:29: But the more startling implication of AdS/CFT is that it’s the first concrete realization of a holographic universe. 00:24: ... of the most startling possibilities is that our 3+1 dimensional universe may better described as resulting ...
	2019-04-03: The Edge of an Infinite Universe 02:26: Let’s start with a quick review of types of universe. 02:48: Travel far enough and you get back where you started. 05:40: As a quick review: start with a graph of space versus time – a spacetime diagram – then compactify. 09:26: Let’s start with another map. 10:11: The basic construction is straightforward enough – start with a circle. 17:49: ... I guess the painful part would be when expansion is fast enough that it starts to disrupt the way chemistry works, without actually ripping matter ... 17:58: ... so there would be some minutes to hours of bad times as our molecules start to betray ... 02:48: Travel far enough and you get back where you started. 17:49: ... I guess the painful part would be when expansion is fast enough that it starts to disrupt the way chemistry works, without actually ripping matter ...
	2019-03-20: Is Dark Energy Getting Stronger? 03:19: ... observations of the cosmic microwave background reveal the starting conditions of the universe – the balance of dark energy, dark matter, ... 03:36: ... we apply the Concordance model to these starting conditions to calculate how the universe should have evolved from those ... 05:21: It may be an issue with how we determine the starting conditions of the universe, or it may be our measurements of supernovae. 11:57: Let’s start with the latter, just in case. 13:07: ... example, there’s the idea that dark energy that started out much stronger dropped off rapidly, or even that it oscillates over ... 15:30: ... you have to do is click on the link the description below, to start today Last week we had a conversation with Richard Branson about his ... 13:07: ... example, there’s the idea that dark energy that started out much stronger dropped off rapidly, or even that it oscillates over ... 03:19: ... observations of the cosmic microwave background reveal the starting conditions of the universe – the balance of dark energy, dark matter, ... 03:36: ... we apply the Concordance model to these starting conditions to calculate how the universe should have evolved from those ... 05:21: It may be an issue with how we determine the starting conditions of the universe, or it may be our measurements of supernovae. 03:19: ... observations of the cosmic microwave background reveal the starting conditions of the universe – the balance of dark energy, dark matter, and ... 03:36: ... we apply the Concordance model to these starting conditions to calculate how the universe should have evolved from those early ... 05:21: It may be an issue with how we determine the starting conditions of the universe, or it may be our measurements of supernovae.
	2019-03-13: Will You Travel to Space? 03:29: ... check out on illegal fishing boats that are ravaging the ocean. We can start monitoring the reefs in a systematic ... 04:47: And that means we can we hope we can generate funds where we can then start thinking about point-to-point travel at great speeds. 09:17: ... the quarter of a million dollars that we currently charge, then we can start building more and more spaceships. And as you build more spaceships the ... 10:16: [RICHARD] You know, my dream will be to let me start the Virgin Hotel. 09:17: ... the quarter of a million dollars that we currently charge, then we can start building more and more spaceships. And as you build more spaceships the price can ... 03:29: ... check out on illegal fishing boats that are ravaging the ocean. We can start monitoring the reefs in a systematic ... 04:47: And that means we can we hope we can generate funds where we can then start thinking about point-to-point travel at great speeds.
	2019-03-06: The Impossibility of Perpetual Motion Machines 14:50: More dense regions were a little hotter, so recombination started later in those.
	2019-02-20: Secrets of the Cosmic Microwave Background 07:42: ... represent the top of the spring's rise which is just determined by its starting position What does this have to do with the second ... 14:23: ... learn more at curiositystream.com/spacetime In our previous episode we started our discussion of the baryon-acoustic oscillation the actual source or ... 07:42: ... represent the top of the spring's rise which is just determined by its starting position What does this have to do with the second ...
	2019-02-07: Sound Waves from the Beginning of Time 01:34: Let's start at the beginning.
	2019-01-30: Perpetual Motion From Negative Mass? 01:24: Let’s start with mass in Newton’s physics. 06:56: At first glance this tells us that any object, no matter its mass, will follow the geodesic determined by its starting position and velocity. 07:40: But those trajectories only depend on the active gravitational mass of the central object, and on the velocity and starting position of the apple. 14:17: Link to that in the description if you want to start choosing your prize. 06:56: At first glance this tells us that any object, no matter its mass, will follow the geodesic determined by its starting position and velocity. 07:40: But those trajectories only depend on the active gravitational mass of the central object, and on the velocity and starting position of the apple. 06:56: At first glance this tells us that any object, no matter its mass, will follow the geodesic determined by its starting position and velocity. 07:40: But those trajectories only depend on the active gravitational mass of the central object, and on the velocity and starting position of the apple.
	2019-01-24: The Crisis in Cosmology 09:15: Well, first you figure out what starting cosmological parameters... 09:21: Those parameters include the starting combination of both dark and light matter, and radiation,... 11:32: So let's start a new list. 09:15: Well, first you figure out what starting cosmological parameters... 09:21: Those parameters include the starting combination of both dark and light matter, and radiation,... 09:15: Well, first you figure out what starting cosmological parameters...
	2019-01-16: Our Antimatter, Mirrored, Time-Reversed Universe 03:02: ... that's not just intuitively expected but also theoretically required. Starting with Julian Schwinger's "Spin statistics theorem" in 1951 it became ... 08:43: ... as a literal rewind. Rewind the universe and you get back to where you started pretty much by definition so presumably quantum information is conserved ... 10:54: ... and then a simple T transformation and you get back to where you started. If CP is violated then this simple time reversal is also violated and we ... 08:43: ... as a literal rewind. Rewind the universe and you get back to where you started pretty much by definition so presumably quantum information is conserved ... 10:54: ... and then a simple T transformation and you get back to where you started. If CP is violated then this simple time reversal is also violated and we ... 08:43: ... as a literal rewind. Rewind the universe and you get back to where you started pretty much by definition so presumably quantum information is conserved in ... 03:02: ... that's not just intuitively expected but also theoretically required. Starting with Julian Schwinger's "Spin statistics theorem" in 1951 it became ... 10:54: ... reverse universe evolves forward in time it should end up back in its starting configuration. On the other hand broken T symmetry says that if you do ...
	2019-01-09: Are Dark Matter And Dark Energy The Same? 06:11: In fact let’s start with dark matter because that’s a bit more straightforward. 10:31: Those supernova results suggest a universe that started expanding rapidly and then slowed down due to the gravity of matter – mostly dark matter.
	2018-12-20: Why String Theory is Wrong 02:14: ... fails, we need to rewind to look at some of these a bit closer, to start with, to a precursor to string theory and the origin of all this extra ... 05:18: So, start with Kaluza-Klein, add vibrating strings and exactly the right extra special dimensions, and you have string theory. 06:03: Superstring started out with incredible promise, and so there was a proliferation of different versions of super string theory.
	2018-12-12: Quantum Physics in a Mirror Universe 00:02: ... just as a reflection in two directions will get you back to where you started a parity transformation followed by a flipping of electric charge ...
	2018-12-06: Did Life on Earth Come from Space? 00:37: ... eyeblink well maybe but it's also possible that life on Earth didn't start on earth at all perhaps it started on a distant world somewhere in the ...
	2018-11-21: 'Oumuamua Is Not Aliens 02:46: Those things are odd, but not odd enough to start assuming aliens. 06:39: The acceleration is the weirdest thing so we'll start there. 15:19: tu_nonna_emiliana asks, if SUSY is easy, just add an s to the start, then how about Sstring? 02:46: Those things are odd, but not odd enough to start assuming aliens.
	2018-11-14: Supersymmetric Particle Found? 11:48: IceCube will start carefully scrutinizing its data.
	2018-11-07: Why String Theory is Right 01:32: It's pretty, or at least it started out that way. 02:41: But the fact is when you start to work out the math of string theory, gravity appears like magic. 03:24: Let's actually start with the regular old point particles of the standard model. 04:06: More technically, you start to get runaway self-interactions, infinite feedback effects between the graviton and its own field. 07:17: Quantizing the motion of strings also starts out ugly, but there are also some math tricks to make it work. 12:18: And this is where string theory starts to look less attractive. 01:32: It's pretty, or at least it started out that way. 07:17: Quantizing the motion of strings also starts out ugly, but there are also some math tricks to make it work. 12:18: And this is where string theory starts to look less attractive.
	2018-10-31: Are Virtual Particles A New Layer of Reality? 01:30: ... started out as a trick to make impossible calculations in quantum field theory ... 03:25: ... the case of the interacting electrons, you start by saying each electron interacts once with the EM field, transferring ... 04:53: All those that both start and end within the diagram are virtual particles. 08:03: ... a bit like the photon starts out moving in the wrong direction and then quantum tunnels between the ... 01:30: ... started out as a trick to make impossible calculations in quantum field theory ... 08:03: ... a bit like the photon starts out moving in the wrong direction and then quantum tunnels between the ...
	2018-10-25: Will We Ever Find Alien Life? 02:32: We have no way to even start to guess that yet. 03:52: And because they almost certainly have a head start on us of at least thousands of years, that galactic gentrification might be visible to us. 06:32: That still seems surprising given those 40 billion possible starting points for life in the Milky Way. 06:51: ... them a million year head start on us, just one 10,000th of the age of the Milky Way, and someone should ... 07:57: ... there aren't tens of thousands of advance civilizations, we can actually start to constrain those biological and sociological ... 06:32: That still seems surprising given those 40 billion possible starting points for life in the Milky Way.
	2018-10-18: What are the Strings in String Theory? 01:52: The idea started in the 60s with efforts to understand the behavior of hadrons, collections of quarks bound by the gluons of the strong nuclear force. 10:01: ... the strings themselves are 1-D, but to even start to produce the properties of known particles, they need to vibrate in ... 11:11: Travel the tiny width of this dimension and you'll find yourself back where you started. 01:52: The idea started in the 60s with efforts to understand the behavior of hadrons, collections of quarks bound by the gluons of the strong nuclear force. 11:11: Travel the tiny width of this dimension and you'll find yourself back where you started.
	2018-10-10: Computing a Universe Simulation 09:33: Protons will have started to decay by the time we simulate last Monday. 13:30: ... due to the fact that the kilonova explosion from the neutron star merger started slightly after the gravitational wave ... 13:41: The gravitational waves start to get strong before the neutron stars even make contact. 09:33: Protons will have started to decay by the time we simulate last Monday. 13:30: ... due to the fact that the kilonova explosion from the neutron star merger started slightly after the gravitational wave ...
	2018-10-03: How to Detect Extra Dimensions 00:34: When does all of that start to happen? 08:10: But it starts to obey the inverse cubed law on much larger scales. 10:10: ... by the gravitational wave, we need to know how intense it was when it started its ... 08:10: But it starts to obey the inverse cubed law on much larger scales.
	2018-09-20: Quantum Gravity and the Hardest Problem in Physics 01:38: Let's start with summaries. 02:41: That math started with the Schrodinger equation, which tracks these probability waves through space and time. 03:27: Starting with the mild, we have the black hole information paradox. 05:08: ... start by thinking about what it means to define a location in a gravitational ... 11:27: Generations of physicists, starting with Einstein himself, spent their lives trying to fix this to unite quantum mechanics and general relativity. 14:53: I said "observable" near the start of the episode. 02:41: That math started with the Schrodinger equation, which tracks these probability waves through space and time. 03:27: Starting with the mild, we have the black hole information paradox. 11:27: Generations of physicists, starting with Einstein himself, spent their lives trying to fix this to unite quantum mechanics and general relativity.
	2018-09-12: How Much Information is in the Universe? 03:20: This probably way underistimates how much info you really need to describe the universe, but let's start with this anyway. 08:55: ... if we started to fill up those empty Planck-sized cubes of space throughout the ... 11:40: ... Starting with our episode on the history of life on Mars, sdushdiu says, Cool, ... 08:55: ... if we started to fill up those empty Planck-sized cubes of space throughout the ... 11:40: ... Starting with our episode on the history of life on Mars, sdushdiu says, Cool, ...
	2018-09-05: The Black Hole Entropy Enigma 03:04: But in our previous episodes we skipped the key insight that started all of this. 03:19: You know, it's almost like all those episodes are starting to come together, almost like we planned this. 04:32: We start, as usual, by collapsing the core of a dead star. 11:26: It's a hell of a conceptual leap given it started with Jacob Bekenstein noticing a peculiar similarity between some formulae. 03:04: But in our previous episodes we skipped the key insight that started all of this. 11:26: It's a hell of a conceptual leap given it started with Jacob Bekenstein noticing a peculiar similarity between some formulae. 03:19: You know, it's almost like all those episodes are starting to come together, almost like we planned this.
	2018-08-30: Is There Life on Mars? 09:56: As of the filming of this video, the storm is only starting to settle down. 11:37: But perhaps the coolest recent discovery is this giant underground lake I mentioned at the start of the episode. 12:57: It didn't take life that long to get started on Earth. 09:56: As of the filming of this video, the storm is only starting to settle down.
	2018-08-23: How Will the Universe End? 03:03: Civilizations may have persisted or even started from scratch in the Red Dwarf Era. 13:55: ... start with, a few of you asked how we know that the g-factor of the electron ... 03:03: Civilizations may have persisted or even started from scratch in the Red Dwarf Era.
	2018-08-15: Quantum Theory's Most Incredible Prediction 00:59: We've talked about QFT many times before, starting with the very first quantum field theory, quantum electrodynamics. 04:49: Thinking of electrons as little bar magnets or as rotating balls of charge is a nice starting point. 00:59: We've talked about QFT many times before, starting with the very first quantum field theory, quantum electrodynamics. 04:49: Thinking of electrons as little bar magnets or as rotating balls of charge is a nice starting point.
	2018-07-25: Reversing Entropy with Maxwell's Demon 06:08: We are no longer in thermal equilibrium, and the entropy is lower than before the demon started. 07:22: ... demon, or the particle sorting system it represents, must start in some known predictable state, which is altered by interaction with a ... 12:01: Starting with this assumption gets you to the Boltzmann equation, and it's a nice, relatively simple way to understand entropy. 06:08: We are no longer in thermal equilibrium, and the entropy is lower than before the demon started. 12:01: Starting with this assumption gets you to the Boltzmann equation, and it's a nice, relatively simple way to understand entropy.
	2018-07-18: The Misunderstood Nature of Entropy 01:43: Let's start from the beginning.
	2018-07-04: Will A New Neutrino Change The Standard Model? 03:43: To explain, we need to start with helicity. 04:14: It flips direction if you start moving faster than the particle. 07:44: So the MiniBooNE experiment starts with muon neutrinos, and some of these transform into electron neutrinos by the time they hit the vat. 11:41: The idea is that if the information is still existent somewhere, then the universe could be put in rewind and it would end up back where it started. 13:22: Weird thing, that's actually how I got started. 13:33: I heard this one guy, he started out memorizing pi to impress chicks, ended up inventing the atomic bomb. 04:14: It flips direction if you start moving faster than the particle. 11:41: The idea is that if the information is still existent somewhere, then the universe could be put in rewind and it would end up back where it started. 13:22: Weird thing, that's actually how I got started. 13:33: I heard this one guy, he started out memorizing pi to impress chicks, ended up inventing the atomic bomb. 07:44: So the MiniBooNE experiment starts with muon neutrinos, and some of these transform into electron neutrinos by the time they hit the vat.
	2018-06-27: How Asteroid Mining Will Save Earth 03:53: Let's start with the good stuff. 06:49: ... in the actual asteroid belt where useful rocks are plentiful, but to start with, it's much easier if the asteroid comes to ... 11:14: So, start a 30-day trial and your first audiobook is free.
	2018-06-20: The Black Hole Information Paradox 07:14: Let's start with the second point. 12:01: So, to continue your own mathematical journey into black holes, Newton's gravity is the place to start.
	2018-05-23: Why Quantum Information is Never Destroyed 02:23: ... symmetric if its equations of motion allow us to perfectly predict the starting point simply by knowing the state of the system at any later ...
	2018-05-16: Noether's Theorem and The Symmetries of Reality 12:47: ... people, on "Space Time," we only ask that you start with a passing familiarity with quantum physics and the etymological ...
	2018-05-09: How Gaia Changed Astronomy Forever 01:33: Let's start with distances. 04:20: We are barely getting started. 09:13: They start out blue and are expected to eventually fade, through white to red to black, but we always call them, white dwarfs. 09:23: They start out red, but heat up over time. 04:20: We are barely getting started.
	2018-04-11: The Physics of Life (ft. It's Okay to be Smart & PBS Eons!) 05:15: We think it started with a self-replicating molecule similar to RNA.
	2018-04-04: The Unruh Effect 03:42: Just before they reach my space-time location, that constant acceleration brings them to a halt, and they start moving back in the opposite direction.
	2018-03-28: The Andromeda-Milky Way Collision 06:20: When those black holes are around a light year apart, they'll start losing orbital energy to gravitational waves.
	2018-03-21: Scientists Have Detected the First Stars 02:11: At least to start with. 02:38: ... a while, the first black holes formed, and started to spew out x-rays, as they gobbled up hydrogen. This heated the gas and ... 06:26: In both cases, the trebuchet counterweight started at the same height and also, reached the same height at the end of its swing. 06:41: To answer this, we need to know how much of the counterweights starting potential energy ends up in the projectile. 06:49: We know that the counterweights height in both shots was the same at the start and at the end of the swing. 07:47: ... only things you needed to know where the starting and final heights of the counterweight and projectile and the mass of ... 02:38: ... a while, the first black holes formed, and started to spew out x-rays, as they gobbled up hydrogen. This heated the gas and ... 06:26: In both cases, the trebuchet counterweight started at the same height and also, reached the same height at the end of its swing. 06:41: To answer this, we need to know how much of the counterweights starting potential energy ends up in the projectile. 07:47: ... only things you needed to know where the starting and final heights of the counterweight and projectile and the mass of ... 06:41: To answer this, we need to know how much of the counterweights starting potential energy ends up in the projectile.
	2018-03-07: Should Space be Privatized? 09:34: The future of human space travel is starting to look promising. 10:19: Roman, we're channeling your contributions towards starting our own aerospace company. 10:23: We'll start small, maybe a skateboard tied to a weather balloon and work up to launching sportscast to the asteroid belt. Baby steps, right? 10:54: In fact, to support the increased gravitational crush of the smaller core, the fusion rate has to be even higher than when it started. 12:04: ... can live hundreds of times longer, even though they have less fuel to start ... 12:18: ... their frictionless trebuchets in a vacuum, while Don Sample suggests we start by assuming a spherical ... 10:23: We'll start small, maybe a skateboard tied to a weather balloon and work up to launching sportscast to the asteroid belt. Baby steps, right? 10:54: In fact, to support the increased gravitational crush of the smaller core, the fusion rate has to be even higher than when it started. 09:34: The future of human space travel is starting to look promising. 10:19: Roman, we're channeling your contributions towards starting our own aerospace company.
	2018-02-28: The Trebuchet Challenge 01:06: Before we get started, you should pause here and watch the previous episode if you haven't already. 01:31: The change in speed for a given object will be the same as long as the start and end points are the same. 07:40: It's enough to know the start and end locations of the counterweight and projectile, along with their masses. 01:06: Before we get started, you should pause here and watch the previous episode if you haven't already.
	2018-02-14: What is Energy? 03:22: It starts moving up with the same speed and kinetic energy it landed with. 04:42: As long as the ball ends up back where it started, it will always have the same combination of kinetic and potential energy as when it left. 12:10: Help support pull the series, and start your free trial by clicking on the link below or going to thegreatcoursesp lus.com/spacetime. 04:42: As long as the ball ends up back where it started, it will always have the same combination of kinetic and potential energy as when it left. 03:22: It starts moving up with the same speed and kinetic energy it landed with.
	2018-01-24: The End of the Habitable Zone 01:53: But as soon as that starts to happen, the drop in energy production disrupts the delicate balance between outward pressure and gravity. 10:09: To really gain intuition about our often very unintuitive universe, you need to start solving problems in physics, math, and astronomy. 01:53: But as soon as that starts to happen, the drop in energy production disrupts the delicate balance between outward pressure and gravity.
	2018-01-17: Horizon Radiation 01:34: ... laws of physics shouldn't change if we go near a black hole or if we start accelerating, but enforcing this isn't automatic, and something has to ... 06:59: Now it starts out with no oscillations, analogous to the vacuum state in quantum field theory. 01:34: ... laws of physics shouldn't change if we go near a black hole or if we start accelerating, but enforcing this isn't automatic, and something has to ... 06:59: Now it starts out with no oscillations, analogous to the vacuum state in quantum field theory.
	2018-01-10: What Do Stars Sound Like? 02:03: When we try to understand other stars, we always start with our sun. 02:20: Understanding asteroseismology starts with understanding helioseismology. 02:27: Understanding helioseismology starts with regular old seismology on earth-- geoseismology. 03:41: They start as traveling waves that can move throughout the stars in a structure. 09:32: To really gain intuition about our often very unintuitive universe, you need to start solving problems in physics, math, and astronomy. 02:20: Understanding asteroseismology starts with understanding helioseismology. 02:27: Understanding helioseismology starts with regular old seismology on earth-- geoseismology.
	2017-12-20: Extinction by Gamma-Ray Burst 01:17: ... get to each of these inevitable cosmic catastrophes, but let's start with the one that could happen any time-- a supernova or gamma-ray burst ... 06:29: Also, extinctions appear to have started before that ice age really got under way. 06:36: Extinction started due to the sudden UV exposure and continued due to climate change. 06:29: Also, extinctions appear to have started before that ice age really got under way. 06:36: Extinction started due to the sudden UV exposure and continued due to climate change.
	2017-12-13: The Origin of 'Oumuamua, Our First Interstellar Visitor 04:44: Now objects falling in from these regions, like comets, only pick up enough speed to bring them back to where they started.
	2017-12-06: Understanding the Uncertainty Principle with Quantum Fourier Series 02:16: To understand the origin of the uncertainty principle, we don't need to know any quantum mechanics, at least not to start with. 12:08: Help support the series and start your free one-month trial by clicking on the link below or going to the greatcoursesplus.com/spacetime.
	2017-11-29: Citizen Science + Zero-Point Challenge Answer 02:39: ... started with this sort of citizen science takes a bit of dedication and cash, ... 05:08: This all started with the City at Home program, which looks through radio data for signs of signals from intelligent life. 02:39: ... started with this sort of citizen science takes a bit of dedication and cash, ... 05:08: This all started with the City at Home program, which looks through radio data for signs of signals from intelligent life.
	2017-11-08: Zero-Point Energy Demystified 02:00: Let's start with the physics.
	2017-10-25: The Missing Mass Mystery 03:23: ... today tells us that there should have been 10 times as much hydrogen to start with than we actually see today in galaxies and ...
	2017-10-19: The Nature of Nothing 12:22: Help support the series and start your free one-month trial by clicking on the link below, or going to thegreatcoursesp lus.com/spacetime.
	2017-10-11: Absolute Cold 07:53: We never would've guessed we'd reach this point when we started making Space Time early in 2015.
	2017-10-04: When Quasars Collide STJC 01:40: They start with masses of up to 10 or so Suns. 12:27: WispXLegend asks where a 15-year-old Australian should start to pursue a career as a physicist. 12:49: Start a Bachelor of Science degree someone with a decent physics program.
	2017-09-28: Are the Fundamental Constants Changing? 12:09: Help support the series and start your free one month trial by clicking on the link below, or going to the TheGreatCoursesP lus.com/SpaceTime.
	2017-09-13: Neutron Stars Collide in New LIGO Signal? 05:59: It was started by a tweet from astronomer J Craig Wheeler about a LIGO detection with an optical counterpart.
	2017-08-24: First Detection of Life 08:37: We've even started to look at super-Earths, like in 55 Cancri e, detecting hydrogen and helium.
	2017-08-16: Extraterrestrial Superstorms 01:22: In fact, let's start with those found on Earth. 12:51: Start moving upwards and end moving downwards.
	2017-08-10: The One-Electron Universe 05:27: ... invert the parity, reverse time-- a particle should end up back where it started. ... 05:37: But if you just flip the charge and in parity-- so do a CP transformation-- you still have to reverse time again to get back where you started. 05:27: ... invert the parity, reverse time-- a particle should end up back where it started. ... 05:37: But if you just flip the charge and in parity-- so do a CP transformation-- you still have to reverse time again to get back where you started.
	2017-08-02: Dark Flow 03:33: And actually, let's just start with the regular old thermal Sunyaev-Zeldovich effect. 12:14: Squid Master started studying physics and got a tattoo of a Feynman diagram, then switched majors to economics.
	2017-07-26: The Secrets of Feynman Diagrams 02:55: This is where we start to see the power and simplicity of this approach. 07:47: To start with, each of the particle paths are actually infinite paths.
	2017-07-19: The Real Star Wars 05:45: So a powerful x-ray laser needs to start with a powerful x-ray source. 13:38: Help support the series and start your free one-month trial by clicking on the link below, or going to thegreatcoursesp lus.com/spacetime.
	2017-07-12: Solving the Impossible in Quantum Field Theory 05:18: And this is where Feynman diagrams start to come in handy, because they keep track of the different families of possibilities. 10:05: ... of trying to start with the unmeasurable fundamental mass of the electron and solve the ...
	2017-07-07: Feynman's Infinite Quantum Paths 06:44: The length of the arrow connecting the start and the end of this chain represents the total probability from all paths. 09:26: Let's not even get started with the complexity of two or more particles interacting.
	2017-06-28: The First Quantum Field Theory 01:55: Now before we start thinking about vibrating quantum fields or even fields at all, let's talk about vibrations. 04:51: Quantum physics may have started with Planck's discovery of the quantum nature of light. 13:12: Help support the series and start your free one-month trial by clicking on the link below or going to TheGreatCoursesP lus.com/SpaceTime. 13:44: In fact, Schrodinger followed the same approach, starting with Einstein's mass energy momentum equation. 01:55: Now before we start thinking about vibrating quantum fields or even fields at all, let's talk about vibrations. 04:51: Quantum physics may have started with Planck's discovery of the quantum nature of light. 13:44: In fact, Schrodinger followed the same approach, starting with Einstein's mass energy momentum equation.
	2017-06-21: Anti-Matter and Quantum Relativity 03:00: The discovery of quantum spin starts with an Austrian physicist named Wolfgang Pauli. 04:51: In a way, he started with relativity. 11:33: Premium membership includes unlimited access to thousands of classes and is available starting at $10 a month. 04:51: In a way, he started with relativity. 11:33: Premium membership includes unlimited access to thousands of classes and is available starting at $10 a month. 03:00: The discovery of quantum spin starts with an Austrian physicist named Wolfgang Pauli.
	2017-06-07: Supervoids vs Colliding Universes! 06:03: ... of the cold spot all the way out to the point where dark energy started to dominate the ... 09:18: At that point, it stops inflating and starts expanding normally. 06:03: ... of the cold spot all the way out to the point where dark energy started to dominate the ... 09:18: At that point, it stops inflating and starts expanding normally.
	2017-05-31: The Fate of the First Stars 02:59: We're starting to think they may be all long dead.
	2017-05-17: Martian Evolution 00:26: And it'll start with Mars. 03:11: Let's start with the one that's hardest to fix-- low gravity. 11:06: Learning this information starts with just spitting into a tube.
	2017-05-10: The Great American Eclipse 02:17: The fun starts at 9:04 AM Pacific time, when the edge of the moon's shadow first reaches the West Coast. 03:47: You start to realize the two objects are the same size on the sky. 05:40: The stars, by the way, start to come out. 02:17: The fun starts at 9:04 AM Pacific time, when the edge of the moon's shadow first reaches the West Coast.
	2017-05-03: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson 02:09: ... in-- is more likely to be one of them-- Than the one universe that started it ... 07:51: This sort of existential angst about disembodied brains being more common than real ones didn't start with Bostrom. 14:58: Particles can start out in a high density configuration, say, in the corner of a room, and then expand. 00:37: In fact, with its director Neil deGrasse Tyson, along with comedian Eugene Mirman, as part of Neil's "StarTalk" radio show. 03:07: You can check out more on "StarTalk" radio, link in the description. 12:20: If you want to see more of my chat with Neil deGrasse Tyson, head over to "StarTalk" radio, "Cosmic Queries," link below. 12:36: It gets pretty philosophical and mind bending, as is much of "StarTalk" radio, very highly recommended. 00:37: In fact, with its director Neil deGrasse Tyson, along with comedian Eugene Mirman, as part of Neil's "StarTalk" radio show. 03:07: You can check out more on "StarTalk" radio, link in the description. 12:20: If you want to see more of my chat with Neil deGrasse Tyson, head over to "StarTalk" radio, "Cosmic Queries," link below. 12:36: It gets pretty philosophical and mind bending, as is much of "StarTalk" radio, very highly recommended. 12:20: If you want to see more of my chat with Neil deGrasse Tyson, head over to "StarTalk" radio, "Cosmic Queries," link below. 03:07: You can check out more on "StarTalk" radio, link in the description. 02:09: ... in-- is more likely to be one of them-- Than the one universe that started it ...
	2017-04-26: Are You a Boltzmann Brain? 11:14: Help support the series and start your free trial by clicking on the link below or going to thegreatcoursesp lus.com/spacetime.
	2017-04-19: The Oh My God Particle 02:13: But weirdly, above a certain height, this radiation starts to increase again. 09:59: Get unlimited access starting at $2.99 a month. 02:13: But weirdly, above a certain height, this radiation starts to increase again.
	2017-04-05: Telescopes on the Moon 04:11: To start with, Earth's thick atmosphere is a powerful buffer against rapid changes in temperature. 09:45: Learning this information starts with just spitting in a tube.
	2017-03-29: How Time Becomes Space Inside a Black Hole 00:47: Let's get started.
	2017-03-22: Superluminal Time Travel + Time Warp Challenge Answer 05:47: And now that you've mastered faster-than-light travel, can you pilot the Paradox back to a point before the race even started? 06:23: ... the Annihilator, we just make sure events stay on the contours that they started ... 08:37: In this case, it's the start of the race. 08:52: These ones represent the regions inaccessible for sublight speed travelers starting at the origin. 09:02: In that frame, the Paradox has moved into a region that appears to be prior to the start of the race. 05:47: And now that you've mastered faster-than-light travel, can you pilot the Paradox back to a point before the race even started? 06:23: ... the Annihilator, we just make sure events stay on the contours that they started ... 08:52: These ones represent the regions inaccessible for sublight speed travelers starting at the origin.
	2017-03-15: Time Crystals! 10:24: Help support the series and start your one month trial by clicking on the link in the description, or going to thegreatcoursesp lus.com/spacetime.
	2017-03-08: The Race to a Habitable Exoplanet - Time Warp Challenge 02:54: So you start work on an Alcubierre warp drive. 03:35: I recommend you start from the perspective of someone waiting around back at Earth. 02:54: So you start work on an Alcubierre warp drive.
	2017-03-01: The Treasures of Trappist-1 02:46: Maybe the TRAPPIST-1 planets started out as mixtures of rock and ice. 06:27: This planetary system probably had a traumatic youth, which may not have been ideal for starting life. 02:46: Maybe the TRAPPIST-1 planets started out as mixtures of rock and ice. 06:27: This planetary system probably had a traumatic youth, which may not have been ideal for starting life.
	2017-02-22: The Eye of Sauron Reveals a Forming Solar System! 02:14: Start with a dense core in a giant molecular cloud. 03:34: They grow in size until they're large enough that they can start collecting more material through collisions. 09:33: Only then can we start to use it to learn about our solar system's early years. 10:05: Get unlimited access starting at $2.99 a month. 03:34: They grow in size until they're large enough that they can start collecting more material through collisions. 10:05: Get unlimited access starting at $2.99 a month.
	2017-02-15: Telescopes of Tomorrow 10:43: Help support the series and start your one-month trial by clicking on the link in the description or going to thegreatcoursesp lus.com/spacetime. 12:35: Well, I would start a YouTube channel called "Will it Spaghettify?"
	2017-02-02: The Geometry of Causality 03:29: They start at the origin, where x and t equals 0.
	2017-01-25: Why Quasars are so Awesome 00:16: Let's talk about what happens when the largest black holes in the universe start to feed. 01:47: Let me start with a bit of history. 08:52: A few billion years after the Big Bang, when the universe was around a quarter of its current age, both starbursts and quasars started to dwindle. 10:54: Help support the series and start your one month trial by clicking on the link in the description, or going to thegreatcoursesp lus.com/spacetime. 08:52: A few billion years after the Big Bang, when the universe was around a quarter of its current age, both starbursts and quasars started to dwindle.
	2017-01-19: The Phantom Singularity 07:40: At that point, the entire equation starts behaving very badly. 09:54: The act of crossing the event horizon is where this singularity really starts to behave badly. 07:40: At that point, the entire equation starts behaving very badly. 09:54: The act of crossing the event horizon is where this singularity really starts to behave badly. 07:40: At that point, the entire equation starts behaving very badly.
	2017-01-11: The EM Drive: Fact or Fantasy? 12:01: At some level, we start to have a pretty thorough grasp of what is possible in this universe.
	2017-01-04: How to See Black Holes + Kugelblitz Challenge Answer 05:59: And that's exactly where we should start. 06:27: The surface of our star is represented by its starting radius at t equals zero, but as time moves forward, the radius shrinks as the star collapses.
	2016-12-14: Escape The Kugelblitz Challenge 01:45: Let's start with a nice, empty universe. 01:52: When the core of this star has fused all of its elements into iron, it will start to collapse under its own weight. 03:51: OK, in the case of the collapsing start, that's still a core, is going to be an insanely hot, dense place and not great for observers.
	2016-12-08: What Happens at the Event Horizon? 05:24: ... a light ray starting from really, really far away and coming towards us hugs the edge of the ... 07:41: With this picture, we can start to answer some very serious questions. 12:14: Help support the series and start your one-month trial by clicking the link in the description or going to thegreatcoursesp lus.com/spacetime. 14:50: ... different particle trajectories, given that the particles supposedly all start at exactly the same ... 15:02: Well, the simple answer is that the particles don't start at exactly the same points. 05:24: ... a light ray starting from really, really far away and coming towards us hugs the edge of the ...
	2016-11-30: Pilot Wave Theory and Quantum Realism 11:33: Now let's not even start talking about gravity-- no version of quantum mechanics has that sorted out.
	2016-11-16: Strange Stars 01:32: Before we can understand strange stars, we need to start with a stellar remnant that we know for sure exists, the neutron star.
	2016-11-09: Did Dark Energy Just Disappear? 13:02: Help support the series and start your one month trial by clicking the link in the description or going to thegreatcoursesplus.com/spacetime. 14:13: ... when the rebellion starts, the centrifuge cities will be an important touchstone in the conflict ...
	2016-10-26: The Many Worlds of the Quantum Multiverse 11:46: You've got a year, starting now.
	2016-10-19: The First Humans on Mars 10:37: Those supermassive black holes started as much smaller seed black holes.
	2016-10-12: Black Holes from the Dawn of Time 10:47: Help support the series and start your one-month trial by clicking the link in the description, or going to thegreatcourses.com/spacetime.
	2016-09-29: Life on Europa? 03:09: In fact, it may be that life on Earth started around its own hydrothermal vents. 06:00: But if life started at those vents, who's to say it stayed there? 03:09: In fact, it may be that life on Earth started around its own hydrothermal vents. 06:00: But if life started at those vents, who's to say it stayed there?
	2016-09-21: Quantum Entanglement and the Great Bohr-Einstein Debate 00:12: The weird phenomenon of quantum entanglement gives us quite startling clues to the answer.
	2016-09-14: Self-Replicating Robots and Galactic Domination 06:09: At some point, the assembler starts building new Von Neumann probes which, one by one, launch to new, more distant star systems. 10:35: Help support the series and start your one-month trial by clicking the link in the description, or going to thegreatcoursesp lus.com/spacetime. 12:23: Shawn Tripp imagines how cool would be if we started exploring the Kuiper Belt, only to find out that it is the remnants of an ancient Dyson sphere. 06:09: At some point, the assembler starts building new Von Neumann probes which, one by one, launch to new, more distant star systems.
	2016-08-24: Should We Build a Dyson Sphere? 02:26: But in the end, it's just not an efficient way to start your galactic empire. 03:10: The crazy thing about the Dyson swarm is that we could probably start building one in the not too distant future. 03:17: In fact, we could get started on the first collector pretty much right away. 04:33: We start with limited mining, space launch, and orbital construction facilities, all of it autonomous. 04:40: Energy supply is the big limiting factor at the start, so it takes about 10 years to build the first collector. 10:47: Help support the series and start your one month trial, by clicking the link below or going to thegreatcoursesp lus.com/spacetime. 03:10: The crazy thing about the Dyson swarm is that we could probably start building one in the not too distant future. 03:17: In fact, we could get started on the first collector pretty much right away.
	2016-08-17: Quantum Eraser Lottery Challenge 00:42: We start with a standard double-slit apparatus. 04:35: Photons start hitting the screen, building up some pattern.
	2016-08-10: How the Quantum Eraser Rewrites the Past 00:25: They imply some startling things about the nature of reality.
	2016-08-03: Can We Survive the Destruction of the Earth? ft. Neal Stephenson 03:57: How much lead time would we really need to build this thing, assuming we started right now? 10:09: ... two, get the hell out of the solar system and start colonizing the galaxy beyond the 30-light-year range of a supernova and ... 03:57: How much lead time would we really need to build this thing, assuming we started right now?
	2016-07-27: The Quantum Experiment that Broke Reality 00:30: [THEME MUSIC] Let's start with the familiar. 00:38: In fact, let's start with a rubber duckie. 00:55: When the new ripples start to overlap each other, they produce this really cool pattern. 03:37: If you keep firing those single photons, you start to see our interference pattern emerge once again. 06:17: Let's start with what we do know about the double-slit result. 06:24: ... starts its journey wherever we put the laser or electron gun or buckyball ... 07:02: ... have this family of could-be trajectories from start to finish and for some reason, when the wave reaches the screen, it ... 11:04: Help support the show and start your one-month trial by going to thegreatcoursesp lus.com/spacetime. 12:14: For Jupiter to form its giant ball of gas, it needed a rocky core to start the process. 06:24: ... starts its journey wherever we put the laser or electron gun or buckyball ...
	2016-07-20: The Future of Gravitational Waves 04:33: As we do so, we'll start to nail down the astrophysics of black hole formation and growth. 07:23: Well, it started tunneling at the edge of the nucleus, around seven femtometers, and tunneled to 27.
	2016-07-06: Juno to Reveal Jupiter's Violent Past 01:08: Jupiter was probably the first planet to start forming in our system. 01:22: ... over 40 times the mass of the Earth before it had enough gravity to start holding on to the 300-ish Earth masses of hydrogen and helium that make ... 04:39: There's more than one possibility, because we don't know exactly how the formation of planets started. 06:03: Well, computer simulations show that something like this may be expected given the right starting position for Jupiter. 07:32: ... events it describes starts after the protoplanetary disk had evaporated, so chronologically, after ... 01:08: Jupiter was probably the first planet to start forming in our system. 01:22: ... over 40 times the mass of the Earth before it had enough gravity to start holding on to the 300-ish Earth masses of hydrogen and helium that make up most ... 04:39: There's more than one possibility, because we don't know exactly how the formation of planets started. 06:03: Well, computer simulations show that something like this may be expected given the right starting position for Jupiter. 07:32: ... events it describes starts after the protoplanetary disk had evaporated, so chronologically, after ...
	2016-06-22: Planck's Constant and The Origin of Quantum Mechanics 11:30: Help support "Space Time" and start your one-month trial by going to thegreatcoursesp lus.com/spacetime.
	2016-06-15: The Strange Universe of Gravitational Lensing 07:20: ... neutron stars, and brown dwarves-- occasionally pass in front of other starts and lens them into brief flashes of increased ... 09:51: We recently started talking about quantum physics by looking at the bizarre phenomena of quantum tunneling. 10:05: ... in your wave function that has an equal or lower energy state than your starting ... 09:51: We recently started talking about quantum physics by looking at the bizarre phenomena of quantum tunneling. 10:05: ... in your wave function that has an equal or lower energy state than your starting ... 07:20: ... neutron stars, and brown dwarves-- occasionally pass in front of other starts and lens them into brief flashes of increased ...
	2016-06-08: New Fundamental Particle Discovered?? + Challenge Winners! 04:20: The LHC is currently offline for upgrades, and starts up again in June, following a two-week delay due to a weasel chewing through a power cable. 07:25: So the feedback cycle can start at either end. 09:03: For the main question, I asked you to figure out how many times the universe doubled in size after dark energy first started to show its influence. 09:37: To start with, let's ask how large this volume was when dark energy only comprised 10% of its total energy. 09:03: For the main question, I asked you to figure out how many times the universe doubled in size after dark energy first started to show its influence. 04:20: The LHC is currently offline for upgrades, and starts up again in June, following a two-week delay due to a weasel chewing through a power cable.
	2016-05-25: Is an Ice Age Coming? 08:05: As ice cover increases, Earth starts to reflect more incoming sunlight. 08:42: First, low obliquity means less overall sun at high latitudes where the glaciers start. 08:05: As ice cover increases, Earth starts to reflect more incoming sunlight.
	2016-05-11: The Cosmic Conspiracy of Dark Energy Challenge Question 05:43: ... I just asked, but also tell me how many billion years ago dark energy started to have a significant effect and how many billion years in the future ...
	2016-05-04: Will Starshot's Insterstellar Journey Succeed? 00:32: We've been waiting so long now that this surety of a space-faring future has started to slip into the realm of science fiction. 07:30: Well to start, it has money. 07:32: Milner has shelled out $100 million to get started. 11:03: ... that we must need some sort of luminosity reference point before we can start using white dwarf supernovae or Type 1a supernovae, the standard ... 11:17: We need to figure out the luminosities for a good number of these supernovae independently, before we can start using them as standard candles. 00:32: We've been waiting so long now that this surety of a space-faring future has started to slip into the realm of science fiction. 07:32: Milner has shelled out $100 million to get started.
	2016-04-20: Why the Universe Needs Dark Energy 11:35: ... and Employers found that new graduates from physics-major programs have starting salaries higher than any other science ... 12:23: Now, before we do any general relativity-- MAN: Start again-- had some eyebrow stuff doing on. 11:35: ... and Employers found that new graduates from physics-major programs have starting salaries higher than any other science ...
	2016-04-13: Will the Universe Expand Forever? 01:17: For today's episode, we're going to start by describing the universe without dark energy. 10:36: ... if you start with an even-atomic-number element-- like carbon, with its six protons-- ...
	2016-04-06: We Are Star Stuff 01:04: ... when those elementary particles start interacting to form nuclei, atoms, and molecules-- chemistry-- they ... 02:37: ... start with the simplest, hydrogen. Your body is up to 60% water, H2O, which ... 03:21: A few seconds after it became possible for protons to exist, new heavier elements started to form. 06:57: That means that as soon as iron starts to fuse, it sucks energy out of the star rather than adding to it. 08:47: ... to accrete, to steal from it enough material, a runaway fusion reaction starts inside the white dwarf that completely obliterates ... 01:04: ... when those elementary particles start interacting to form nuclei, atoms, and molecules-- chemistry-- they result in levels ... 03:21: A few seconds after it became possible for protons to exist, new heavier elements started to form. 00:55: Perhaps not fully comprehend, but at least deduce and manipulate with startling precision and predictive power. 06:57: That means that as soon as iron starts to fuse, it sucks energy out of the star rather than adding to it. 08:47: ... to accrete, to steal from it enough material, a runaway fusion reaction starts inside the white dwarf that completely obliterates ...
	2016-03-23: How Cosmic Inflation Flattened the Universe 03:12: An expanding universe doesn't tend to stay flat, even if it starts that way. 03:44: If the universe starts out even a little bit not flat, then that not-flatness will amplify quickly. 04:49: It goes like this-- start with a universe so crunched down that the entire currently observable part of it was all causally connected. 08:52: It may have, and there are some ideas about what got it started. 09:17: When first conceived, the inflationary period was thought to have started at a particular point after the instant of the Big Bang. 08:52: It may have, and there are some ideas about what got it started. 09:17: When first conceived, the inflationary period was thought to have started at a particular point after the instant of the Big Bang. 03:12: An expanding universe doesn't tend to stay flat, even if it starts that way. 03:44: If the universe starts out even a little bit not flat, then that not-flatness will amplify quickly.
	2016-03-16: Why is the Earth Round and the Milky Way Flat? 00:49: Let's start with equilibrium. 02:14: So let's start with that. 08:56: They also start out spinning very slowly, but that spin speeds up as they collapse, just like a spinning ice skater.
	2016-03-02: What’s Wrong With the Big Bang Theory? 07:52: ... idea is the universe started subatomic, small enough that it was able to even out its temperature and ...
	2016-02-24: Why the Big Bang Definitely Happened 00:00: Our universe started with the Big Bang, or did it? 01:36: Let's start with the irrefutable. 00:00: Our universe started with the Big Bang, or did it? 07:27: It's in startling agreement with what we see when we look out there.
	2016-02-03: Will Mars or Venus Kill You First? 01:04: We'll start with Mars, because it sits in popular consciousness as our go-to Earth 2.0. 03:13: But it does start to form bubbles of nitrogen and oxygen, and this is what will actually kill you. 06:53: To start with, things seem lovely. 07:26: Your skin will start to blister and dissolve at the same time.
	2016-01-27: The Origin of Matter and Time 00:10: In recent episodes, we started breaking apart our preconceived notions of these ideas. 12:17: The start of the song time should sync with the appearance of the photon clock. 00:10: In recent episodes, we started breaking apart our preconceived notions of these ideas.
	2016-01-13: When Time Breaks Down 00:27: While weekends and summer break seem to finish even before they start. 01:50: This is where our conception of time starts to break down. 03:26: The rate of ticks is consistent, time flows smoothly, until the clock starts moving relative to me. 01:50: This is where our conception of time starts to break down. 03:26: The rate of ticks is consistent, time flows smoothly, until the clock starts moving relative to me.
	2016-01-06: The True Nature of Matter and Mass 01:33: A good place to start is with a thought experiment that we'll call a photon box. 03:58: Push the spring, and it doesn't all start moving instantly.
	2015-11-25: 100 Years of Relativity + Challenge Winners! 01:24: On December 9, we'll delve deeper than ever into the weirdness of black holes, after which we'll start exploring the nature of matter and time. 02:39: In the asteroid's frame, its starting velocity is zero. 03:41: ... one relating change in position, average acceleration, and time, with a starting velocity of zero in the frame of Apophis in ... 01:24: On December 9, we'll delve deeper than ever into the weirdness of black holes, after which we'll start exploring the nature of matter and time. 02:39: In the asteroid's frame, its starting velocity is zero. 03:41: ... one relating change in position, average acceleration, and time, with a starting velocity of zero in the frame of Apophis in ... 02:39: In the asteroid's frame, its starting velocity is zero. 03:41: ... one relating change in position, average acceleration, and time, with a starting velocity of zero in the frame of Apophis in ...
	2015-11-18: 5 Ways to Stop a Killer Asteroid 06:20: In fact, I don't want to attempt more than one, because once the first one fails, it may be too late to start again.
	2015-11-05: Why Haven't We Found Alien Life? 09:19: ... planets in the galaxy, only a tiny fraction needed to have a small head start on us in order to have produced the Federation of Planets and Stargates ... 09:31: So what if humanity started early? 11:31: ... point of this philosophy is that the alien hypothesis is a bad place to start because you can explains almost any weird natural phenomenon as having ... 09:31: So what if humanity started early?
	2015-10-28: Is The Alcubierre Warp Drive Possible? 02:16: But if you're cheeky, you can actually just make up a solution to the equations of GR without starting with a real mass/energy distribution.
	2015-10-22: Have Gravitational Waves Been Discovered?!? 07:42: ... even though advanced LIGO only started running a few weeks ago on September 18, some predictions tell us that ...
	2015-10-15: 5 REAL Possibilities for Interstellar Travel 09:44: They land us on Alpha Cen in the latter half of the 2100s, assuming we start now.
	2015-10-07: The Speed of Light is NOT About Light 11:17: RedomaxRedomax asks what you would see if you traveled 18 times the distance to the particle horizon to come back to where you started. 11:39: ... froze in its expansion, which it won't-- then you'd get back to your starting point a long, long, long time ... 11:17: RedomaxRedomax asks what you would see if you traveled 18 times the distance to the particle horizon to come back to where you started. 11:39: ... froze in its expansion, which it won't-- then you'd get back to your starting point a long, long, long time ...
	2015-09-30: What Happens At The Edge Of The Universe? 01:22: Let's start with that 46 billion light year number. 06:36: In that case, our warp-ship would eventually travel all the way around this curved hypersphere and get back to where it started. 06:46: ... 18 times the distance to the particle horizon to get back to where you started, assuming expansion froze for the whole ... 06:36: In that case, our warp-ship would eventually travel all the way around this curved hypersphere and get back to where it started. 06:46: ... 18 times the distance to the particle horizon to get back to where you started, assuming expansion froze for the whole ...
	2015-09-23: Does Dark Matter BREAK Physics? 02:00: OK, let's start with the first possibility. 04:17: But you can't just break general relativity and start over.
	2015-08-27: Watch THIS! (New Host + Challenge Winners) 00:13: Let's start with the answer to the Newtonian version. 04:04: You start with the general spherical symmetric metric. 04:57: And you pretty much have to start from scratch.
	2015-08-19: Do Events Inside Black Holes Happen? 06:59: That's not the reason, but here's my guess about how this unfortunate metaphor started.
	2015-08-05: What Physics Teachers Get Wrong About Tides! 05:46: So I think you can start to see what's happening here. 05:59: ... same way that a blister or a pimple will bulge up in the center if you start to squeeze it from the ... 10:53: ... when you start looking at very small scales, like what the quantum version of gravity ... 15:07: This stuff takes years to grasp and you're getting a head start Glad you're watching the show. 10:53: ... you on very small scales or very high energies, that a lot of infinities start popping up in the theory that you can't get rid of, which is what we don't have ...
	2015-07-29: General Relativity & Curved Spacetime Explained! 01:51: Let's start with Newton.
	2015-07-22: SPECIAL ANNOUNCEMENT + Flat Spacetime Geometry Comments 00:24: ... down as the writer and host of "PBS Space Time." This fall, I'll be starting full-time work at the US National Science ... 02:03: But as John Buluba and [INAUDIBLE] pointed out, after you view it a second time, it starts to make more sense. 04:57: But here's a preview of something that we're going to do next week that I want you to start chewing over. 00:24: ... down as the writer and host of "PBS Space Time." This fall, I'll be starting full-time work at the US National Science ... 02:03: But as John Buluba and [INAUDIBLE] pointed out, after you view it a second time, it starts to make more sense.
	2015-07-15: Can You Trust Your Eyes in Spacetime? 01:21: Let's get started. 06:07: For starters, this spacetime really is flat.
	2015-07-08: Curvature Demonstrated + Comments 03:33: Starts here. 04:51: ... the vector you get back in New York isn't parallel to the one that you started ... 05:27: ... vector around the circle and see if you end up with the same vector you started ... 04:51: ... the vector you get back in New York isn't parallel to the one that you started ... 05:27: ... vector around the circle and see if you end up with the same vector you started ... 03:33: Starts here.
	2015-07-02: Can a Circle Be a Straight Line? 00:45: We actually started this campaign in our "Is Gravity an Illustion?" episode. 02:22: Let's start with this picture of the flat Euclidean 2D plane from high school math class. 05:55: Parallel transport a vector around a closed curve starting at A and going all the way back to A. 06:00: If you end up with the same vector you started with, your space is flat. 06:14: But if those geodesics start converging or diverging at any point, then the space is curved. 07:03: If you end up with the same vector you started with space is flat, if not, it's curved. 06:14: But if those geodesics start converging or diverging at any point, then the space is curved. 00:45: We actually started this campaign in our "Is Gravity an Illustion?" episode. 06:00: If you end up with the same vector you started with, your space is flat. 07:03: If you end up with the same vector you started with space is flat, if not, it's curved. 05:55: Parallel transport a vector around a closed curve starting at A and going all the way back to A.
	2015-06-24: The Calendar, Australia & White Christmas 01:47: Now, eventually, the cycle of seasons will backtrack a full 360 degrees, returning to its starting point.
	2015-06-17: How to Signal Aliens 00:49: Let's start with the radio. 10:33: ... to you now that we've given the answer, I encourage you guys to start talking amongst ourselves in the ...
	2015-06-03: Is Gravity An Illusion? 02:05: For example, suppose that you're in a train car that starts accelerating uniformly forward along a flat track.
	2015-05-27: Habitable Exoplanets Debunked! 01:45: Basically the habitable zone is more of a guideline, a starting point to narrow down targets of interest. 01:50: Those estimates you hear of an average of one habitable planet per star in the Milky Way are really just statements about this starting point. 01:45: Basically the habitable zone is more of a guideline, a starting point to narrow down targets of interest. 01:50: Those estimates you hear of an average of one habitable planet per star in the Milky Way are really just statements about this starting point. 01:45: Basically the habitable zone is more of a guideline, a starting point to narrow down targets of interest. 01:50: Those estimates you hear of an average of one habitable planet per star in the Milky Way are really just statements about this starting point.
	2015-05-20: The Real Meaning of E=mc² 00:51: ... we can get a better sense of what m equals E over c squared means if we start with some things that it implies that seem at odds with our everyday ... 01:42: ... of that watch that heats them up ever so slightly so that its atoms start jiggling a little ... 03:32: Whenever you turn on a flashlight, its math starts to drop immediately. 01:42: ... of that watch that heats them up ever so slightly so that its atoms start jiggling a little ... 03:32: Whenever you turn on a flashlight, its math starts to drop immediately.
	2015-05-13: 9 NASA Technologies Shaping YOUR Future 00:27: What do you do with your hand inevitably gets tired and you start losing grip strength? 09:11: Agreed, but Venus missions are shorter, so the relative cost savings of all female crews start to become less significant. 00:27: What do you do with your hand inevitably gets tired and you start losing grip strength?
	2015-05-06: Should the First Mars Mission Be All Women? 00:47: Let's start with the physiological arguments for all-female missions beyond Earth's moon.
	2015-04-29: What's the Most Realistic Artificial Gravity in Sci-Fi? 01:39: And in the process, the wall starts pushing hard against your back. 03:05: Let's start with the iconic scene of Frank Poole jogging around the rotating command module in "2001: A Space Odyssey." Poole's height is 1.8 meters. 08:45: But first, an announcement-- a viewer, not us, started a sub-Reddit dedicated to our program as an alternate form for episode discussion. 10:40: ... for starters, do some background reading on something called "decoherence." On a ... 01:39: And in the process, the wall starts pushing hard against your back.
	2015-04-22: Are Space and Time An Illusion? 02:35: A good starting point for objective reality is universal agreement. 07:10: Last week, we asked whether NASA could start a zombie apocalypse. 02:35: A good starting point for objective reality is universal agreement.
	2015-04-15: Could NASA Start the Zombie Apocalypse? 00:13: Could a zombie apocalypse start with a routine trip to space? 00:31: And the zombie phenomenon starts unexpectedly and spreads quickly, which is why it wreaks so much havoc. 01:08: But maybe they should because one scenario that's more plausible than you might think is that a zombie apocalypse could start in space. 01:20: Let's start with bacteria. 04:16: Will the zombie apocalypse start in space. 00:31: And the zombie phenomenon starts unexpectedly and spreads quickly, which is why it wreaks so much havoc.
	2015-04-08: Could You Fart Your Way to the Moon? 00:42: Let's start with rockets, actually, because there's a common misconception I want to clear up from the start. 02:48: In truth, even starting out from low Earth order, you'd be short of Earth's escape velocity by a factor of about a billion. 03:11: Let's start with the exhaust velocity of a fart. 02:48: In truth, even starting out from low Earth order, you'd be short of Earth's escape velocity by a factor of about a billion.
	2015-04-01: Is the Moon in Majora’s Mask a Black Hole? 01:44: So let's get started. 02:15: The key evidence appears in the scenes just before the moon hits, when loose rocks start flying upward off the surface of the planet. 06:13: You could start with a more massive and larger black hole and just let it evaporate slowly. 08:03: And as far as I know, the first stars didn't start forming until a couple hundred million years or so after the sky went dark. 02:15: The key evidence appears in the scenes just before the moon hits, when loose rocks start flying upward off the surface of the planet. 08:03: And as far as I know, the first stars didn't start forming until a couple hundred million years or so after the sky went dark. 01:44: So let's get started.
	2015-03-18: Can A Starfox Barrel Roll Work In Space? 02:41: ... small thrusters on the top and bottom of each wing, one quick burst to start to ship rotating and then another opposing burst to stop ... 03:23: By rotating the flywheel quickly, I end up transferring its angular momentum to myself, so I start spinning. 04:04: When I flip the flywheel 180 degrees, its individual angular momentum starts pointing toward the rear of the ship, i.e. 07:41: ... are unstable, and in quadrillions of years, individual nuclei will start falling ... 03:23: By rotating the flywheel quickly, I end up transferring its angular momentum to myself, so I start spinning. 04:04: When I flip the flywheel 180 degrees, its individual angular momentum starts pointing toward the rear of the ship, i.e.
	2015-03-11: What Will Destroy Planet Earth? 00:50: Let's review some possibilities, starting with one that has probably crossed your mind at some point-- nukes. 03:19: But in 1%, the inner planet orbits stretch out after about three billion years and Earth starts doing drive-bys of Venus and Mars. 05:43: ... between 100 billion and a few trillion years from now, space could start to stretch-- not just at faster rates, but on smaller and smaller ... 00:50: Let's review some possibilities, starting with one that has probably crossed your mind at some point-- nukes. 03:19: But in 1%, the inner planet orbits stretch out after about three billion years and Earth starts doing drive-bys of Venus and Mars.
	2015-03-04: Should We Colonize Venus Instead of Mars? 01:36: If we ever start a colony, we'll need to bring along almost everything. 04:54: ... in the favorable gravity, and it starts to look like the upper atmosphere of Venus might be the closest thing in ... 06:07: If we start a grassroots movement, I'll let you know on the next episode of "Space Time". 01:11: For starters, Venus is closer to Earth. 04:54: ... in the favorable gravity, and it starts to look like the upper atmosphere of Venus might be the closest thing in ...
	2015-02-25: How Do You Measure the Size of the Universe? 01:18: In a nutshell, you start with the age of the universe. 05:28: If you're inclined, go ahead and get the discussion about that started in the comments below.
	2015-02-18: Is It Irrational to Believe in Aliens? 00:39: So where do we start? 02:07: Let's start with a pro aliens argument, that intelligent life should exist. 02:53: ... compensate with billions or trillions of habitable worlds, it would start to look like a cosmic conspiracy, like Earth and humanity are absurdly ...
	2015-02-11: What Planet Is Super Mario World? 00:21: Let's start with how gravity affects motion, because that a huge effect on jumping.

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