Search PBS Space Time


2022-11-23: How To See Black Holes By Catching Neutrinos

  • 12:30: The future of neutrino astronomy is bright, and it’s hard to even guess what we’ll learn as we slowly build our neutrino map of space time.

2022-11-16: Are there Undiscovered Elements Beyond The Periodic Table?

  • 00:26: ... elements whose incredible properties will propel us into our star-faring future. ...
  • 15:46: ... them, hoping to gain new ground in humanity's journey to further and future horizons of space ...
  • 16:37: ... the hypothesis that says that the future emergence of new civilizations has to be cut off at some point, or else ...
  • 17:35: ... selected from the set of all actually existent(past, present and future) observers in their reference ...

2022-11-09: What If Humanity Is Among The First Spacefaring Civilizations?

  • 00:38: ... years, and the heat death of the universe is a googol years in the future, that’s 1 with a hundred ...
  • 02:14: Maybe the future history of the universe isn’t as hospitable to life after all.
  • 02:22: I mean, how can we know what the future history of the universe will be?
  • 02:26: ... it IS possible to say something about the earliness of humanity and the future of life just based on our arrival date and the apparent emptiness of the ...
  • 04:05: ... when habitable worlds formed in the past or when they will form in the future. ...
  • 04:29: And around 20 billion years in the future, there won’t be enough interstellar material left to form new stars.
  • 08:00: If it’s possible for life to evolve on these planets, then new civilisations could continue to emerge for trillions of years into the future.
  • 09:47: ... from very drawn-out evolutionary processes trillions of years in the future. ...
  • 10:24: ... come up with some plausible scenario that limits the number of possible future civilizations, even in the case that we should expect them based on the ...
  • 10:37: ... civilisations: some catastrophic event that will happen one day in the future that prevents any new intelligent life from ...
  • 11:01: The model claims that at some point in the future, all habitable planets will be occupied by rapidly expanding alien civilizations.
  • 12:06: ... to tune the parameters of the model to cut off just the right amount of future births of new civilisations to give us a typical, run-of-the-mill birth ...
  • 12:19: If grabby civilizations aren’t common enough, they won’t prevent enough future births to make us typical rather than early.

2022-10-19: The Equation That Explains (Nearly) Everything!

  • 15:40: ... across space and time, just like you Vivaan. We wish you a most luminous future. ...

2022-09-21: Science of the James Webb Telescope Explained!

  • 11:09: If anyone sends us their there own processing of JWST data we’ll try to show who it in a future episode.

2022-08-24: What Makes The Strong Force Strong?

  • 15:09: As you can imagine, there’s a lot more to it - and so in future episodes we’ll dive deeper into the strongest force in all of space time.

2022-08-17: What If Dark Energy is a New Quantum Field?

  • 10:08: ... The universe will spend the vast, vast majority of both its past and future history with a huge difference between the densities of dark energy and ...

2022-08-03: What Happens Inside a Proton?

  • 00:22: ... and basically become   wizards capable of predicting the future  and manipulating the foundations of ...

2022-07-27: How Many States Of Matter Are There?

  • 13:18: ... check out “Far Out” which explores the future of science, technology, and culture, and how these changes may affect ...

2022-07-20: What If We Live in a Superdeterministic Universe?

  • 09:44: But what if, instead, the future decisions of Alice and Bob are influenced within that past overlap.
  • 15:36: That's especially true when it comes to planning for the future of a YouTube show.
  • 18:30: No Star Trek future unless you can assemble furniture without destroying your planet.

2022-06-30: Could We Decode Alien Physics?

  • 00:00: ... the perhaps not too distant future, every radio telescope on Earth receives the same massive ...
  • 11:52: ... how the aliens define   the flow of time. Do they define the future as an increasing progression of positive times like we ...

2022-06-22: Is Interstellar Travel Impossible?

  • 03:14: Some of these may be achievable in the distant but foreseeable future.
  • 03:55: This is the number one potential dealbreaker for our future as a galactic species.
  • 04:02: ... glorious star-spanning future depends on the answer to a rather mundane question: can a ship large ...

2022-05-25: The Evolution of the Modern Milky Way Galaxy

  • 01:41: ... a detailed and dynamical map of the Milky Way. We can predict its future mergers with   the Magellanic clouds and Andromeda - but ...

2022-05-04: Space DOES NOT Expand Everywhere

  • 00:19: ... the beginning of the universe at the big bang, and lets us predict its future - it’ll probably expand forever, ...
  • 10:06: ... talked about before. All spacetime paths can be traced to the infinite future or past until they hit a singula,rity - the big bang or a black hole. As ...

2022-04-20: Does the Universe Create Itself?

  • 14:50: ... Retherford asks whether a fair answer would be “It’s expanding into the future.” I don’t know how fair it would be, but I’m going to steal it anyway. But ...

2022-03-30: Could The Universe Be Inside A Black Hole?

  • 03:01: ... past for all of space, while the black hole singularity exists in the future for all of the balck hole ...
  • 04:24: ... you can keep tracing the geodesic into the infinite future or all the way back to the Big Bang - it’s defined for all past and ...
  • 05:01: A black hole contains a future, space-like singularity.
  • 05:05: Which means that all geodesics within a black hole spacetime end at the singularity in the future.
  • 05:19: ... black hole singularity is the all-encompassing future for the spacetime that lives beneath the event horizon in the same way ...

2022-03-08: Is the Proxima System Our Best Hope For Another Earth?

  • 07:24: Surely we’d identified the first port of call for our interstellar future.

2022-02-23: Are Cosmic Strings Cracks in the Universe?

  • 10:09: ... to be seen at our current detectors such as LIGO,   but future detectors such as LISA might be  sensitive enough. Then there’s the ...

2022-02-16: Is The Wave Function The Building Block of Reality?

  • 05:09: ... is that it’s time-reversal-symmetric. Running it forwards generates future states, but running it backwards lets you perfectly recover the past ...

2022-02-10: The Nature of Space and Time AMA

  • 00:03: ... us i guess that my perception of now could be some other observer's future and yet another observer's past and this leads us to the notion of ...

2022-01-19: How To Build The Universe in a Computer

  • 00:16: Perhaps their denizens will look back with relief as the dislocated galaxies retreat on their future night skies.
  • 00:47: ... of countless stars and gas and dark matter particles over billions of future ...
  • 03:06: And then to solve those equations to find their positions at any time in the future.
  • 03:17: For 3 or more bodies there  is no simple set of equations   describing their future evolution under gravity.

2022-01-12: How To Simulate The Universe With DFT

  • 20:19: ... matryoshka brain. Our awesome space-faring, megastructure-building future suddenly sounds a lot more ...

2021-12-29: How to Find ALIEN Dyson Spheres

  • 13:48: It would also point to a possible future for humanity - something we might want to do when we grow up.
  • 13:55: ... would show us that we might even have a future - one that could even leave our own astroengineering mark on the galaxy, ...

2021-12-20: What Happens If A Black Hole Hits Earth?

  • 13:13: ... episodes that many of you have strong opinions on our space faring future, so check out the episode, drop your thoughts into the comments and let ...

2021-12-10: 2021 End of Year AMA!

  • 00:02: ... babbling that i won't subject you to right now but you know future episodes um there was a really good one from let's see how about ...

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.

2021-09-21: How Electron Spin Makes Matter Possible

  • 18:19: ... cases even faster. I will try to speak with better error bars in the future. ...

2021-08-10: How to Communicate Across the Quantum Multiverse

  • 01:46: ... wavefunction is the reality, encompassing all possible histories and futures and all exist. But we are only sensitive to a slice of the wavefunction ...
  • 12:47: ... must be true. Perhaps there’s a me on a different timeline, or in the future, who’s smart enough to figure all of this out and is now sending me a ...
  • 15:46: ... pressure, the fusion rate, etc. You can actually defuse a potential future supernova by sucking away its outer layers. The question is the can you ...

2021-07-13: Where Are The Worlds In Many Worlds?

  • 12:26: But that’s for another time - and I’ll do my best to bring it to every future branch of our splitting quantum space time.

2021-06-23: How Quantum Entanglement Creates Entropy

  • 15:02: ... between exponential processes.   For example, presumably our future AI overlords will be better at managing our orbital ...

2021-06-16: Can Space Be Infinitely Divided?

  • 11:26: ... smaller parts. You’ll have to stay tuned to the show, and to the future   of physics, to find out what might lie beneath the smallest ...

2021-06-09: Are We Running Out of Space Above Earth?

  • 03:59: And their future trajectories can be calculated to predict possible future collisions.

2021-05-25: What If (Tiny) Black Holes Are Everywhere?

  • 03:45: ... gives us this nice picture of a far, far distant future in which the stars have gone out and we only have black holes, which one ...
  • 14:45: We said that LIGO is planning to begin using squeezed light in a future run.

2021-04-21: The NEW Warp Drive Possibilities

  • 00:00: That Einstein guy was a real bummer for our hopes of a star-hopping, science-fiction-y future.
  • 12:18: Einstein and the universe appear to be trolling us - alternately inspiring and crushing our hopes for a star-hopping future.
  • 13:48: Future versions will be even better.

2021-04-07: Why the Muon g-2 Results Are So Exciting!

  • 11:38: In fact, I expect a flurry of theoretical papers in the very near future.

2021-03-23: Zeno's Paradox & The Quantum Zeno Effect

  • 12:17: ... quantum zeno experiments are difficult, and perhaps future brilliant tests will give us clues to unravel the deepest mysteries at ...

2021-03-09: How Does Gravity Affect Light?

  • 07:49: The sum of all those waves perfectly describes the future evolution of the original wave.

2021-01-19: Can We Break the Universe?

  • 07:00: The traveling twin declares that multiple points in the stationary twin’s past and future are all happening in her present.
  • 07:07: So by traveling around the universe, she’s actually traveling towards one of those future versions.
  • 07:12: And those future versions are older - by just enough to agree with the time dilation that the stationary twin would calculate.
  • 11:34: But there’s no collision, because the nose of the spaceship exists in the future, and the tail in the past.

2020-12-15: The Supernova At The End of Time

  • 01:14: ... among you, grab your popcorn because your favorite TV show - AKA the far future of the universe - just got renewed for another ...
  • 03:03: ... Chandrasekhar - Chandra to his friends - was pondering the far future of the star whose warm light now bathed the ...
  • 06:46: Okay, let’s fast forward our story just a little bit - to the very long, boring future of a stellar remnant below the Chandrasekhar limit.
  • 07:35: ... the temperature of the ambient space - now a frigid 3 Kelvin, but in the future even colder than that as the universe expands and the cosmic background ...
  • 09:40: This absurdly long and dull future may have been given a little more sparkle.
  • 11:03: ... result in a new type of supernova that will only happen in that distant future - a black dwarf ...
  • 11:45: ... thing to look forward to - Iron stars exploding in unimaginably distant future of space ...
  • 12:33: In the last episode we did one of our more "woah dude" topics yet - Why do we remember the past and not the future?
  • 13:21: When you look at the whole universe at once, it can be said to remember its future.
  • 13:26: A future collision between two objects is "remembered" by their current movement toward each other.
  • 13:37: ... information of a future collision is spread out, spatially, before the collision: to "remember" ...
  • 13:53: ... them both." So there you have it - the universe remembers both past and future perfectly, but individual chunks of the universe only remember in the ...
  • 14:28: If correlations grew in the opposite direction - the wave flowed backwards, our definition of future and past would flip.
  • 14:43: ... quote: even if time did flow backwards, from future to past, in each time step we would not remember the "previous" one (the ...
  • 15:49: ... a Many Worlds multiverse, and complains they actually can remember the future, but unfortunately can't decide which of the futures is the real ...
  • 15:59: I'm afraid all of them are - you're remembering the many real branches of your future-slash-past.

2020-12-08: Why Do You Remember The Past But Not The Future?

  • 00:00: The laws of physics don’t specify an arrow of time - they don’t distinguish the past from the future.
  • 00:23: In other words why do we remember the past and not the future?
  • 03:47: But it doesn’t appear correlated with the future.
  • 03:50: What is the future of that rock?
  • 04:02: ... it isn’t destroyed by future violence, then fast forward many, many times the current age of the ...
  • 05:30: The weird thing here is that the same proton has as much “memory” of its future as it does of its past.
  • 06:20: And then in the far, far future the rock decays.
  • 07:31: But what about the future?
  • 07:41: ... precise future would be recorded in its present - it would “remember” that future in ...
  • 08:06: ... we can definitely say that the rock does NOT remember its entire future, because there’s no way you could predict that future cosmic ray strike ...
  • 09:07: And it is already correlated with everything else in its environment that will happen to interact with it in the future.

2020-11-18: The Arrow of Time and How to Reverse It

  • 00:10: So why do we seem to be stuck in this inexorable flow towards the future? It's time to begin our journey towards really understanding time.
  • 00:24: ... the universe at the next. But those laws don’t distinguish between the future and the past. Reverse the flow of time and their equations work exactly ...
  • 00:54: ... an ordered sequence of prior events. We remember the past, but not the future. ...
  • 01:21: ... of this - How does entropy break the symmetry of time, and cause the future to differ from the past. We’ll follow with an episode exploring why this ...
  • 02:53: ... our block universe. Time has a symmetry in the sense that the past and future aren’t differentiated by the laws of physics. And those laws don’t even ...
  • 05:43: ... we defined the “up” time direction in the block universe as “towards the future”. But what does this look like going backwards in time? Uh, exactly the ...
  • 09:39: ... increasing entropy? To understand why we only remember the past, not the future, we need to delve deeper. In fact it involves information theory and ...

2020-11-11: Can Free Will be Saved in a Deterministic Universe?

  • 00:36: In it, the past and future have a sort of eternal timeless existence from the point of view of some god-like observer outside both space and time.
  • 00:57: ... perfect knowledge of the laws of nature could calculate perfectly all future states of the ...
  • 04:23: ... just not be predictable even in principle by any arbitrarily precise far future brain scanning ...
  • 04:45: ... there are other requirements we could place, like three, that the future not be predefined and not singular, or four, we could require that the ...
  • 08:40: What if some future type of brain scan allows 98% predictability of your choices?
  • 09:15: The short answer is we don't know how well we'll ever be able to forward model a brain's behavior, even with the best future technology.
  • 09:55: Another important consideration is whether or not the future is actually singular and determined, regardless of the existence of any agents of choice.
  • 10:04: In the Copenhagen interpretation, the future is singular but undetermined.
  • 10:09: One future will happen, but it's impossible to predict what it will be.
  • 10:12: In the many worlds interpretation, the future is plural and determined.
  • 10:17: All possible futures exist and develop according to the laws of quantum mechanics.
  • 10:24: ... our brains play a part choosing what future happens or the choices we experience are the process of choosing which ...
  • 10:37: The case where free will may really struggle is the case of a singular determined future.

2020-11-04: Electroweak Theory and the Origin of the Fundamental Forces

  • 03:58: Though as we’ll discuss in a future episode, that’s not the full story.

2020-10-27: How The Penrose Singularity Theorem Predicts The End of Space Time

  • 08:49: ... held that geodesics could be traced  indefinitely into the past and future.   All of spacetime should be a smooth, if  curved structure - a ...
  • 12:51: ... incomplete - rather it extends   infinitely into the future AND the past. With your help Space Time might do the same. Well, ...

2020-10-20: Is The Future Predetermined By Quantum Mechanics?

  • 00:13: And does that mean that the future is predestined?
  • 00:31: In a block universe of Einstein's relativity, there's no way to cleanly define the present and so no way to cleanly separate the future from the past.
  • 00:52: ... observer who lives in their definition of the present, but for whom your future is already the ...
  • 01:04: Or for whom your past is their future.
  • 01:10: ... their perception of the present is as valid as ours, then all of the future is ...
  • 01:47: ... a good description of space and time, what would it take for our future to remain ...
  • 02:00: ... the entire block universe is defined, past, present, and future, or everything outside our past light cone is undefined, including other ...
  • 05:31: So how do these interpretations connect with what relativity tells us about past, future, and present?
  • 06:01: That leaves your future light cone undefined.
  • 06:25: Your future is intact.
  • 06:38: In fact, any part of spacetime, not in your future light cone is potentially the past for another observer in your present.
  • 06:46: ... can imagine a third observer on their different present for whom your future light cone is in their past light cone so it should have already been ...
  • 06:58: ... in other observers there's no way to keep the wave function of your future from being collapsed before you get ...
  • 07:43: But that doesn't help un-collapse your future.
  • 07:46: ... collapse interpretation like Copenhagen, to give you an un-collapsed future is if you are the only being doing the wave function collapsing let's ...
  • 08:03: This interpretation sits a bit better with the relativity of past, present, and future.
  • 10:07: So what does all of this say about determinism and the reality of your past and future?
  • 10:18: ... means all future branching of the wave function of your present, by which I mean the ...
  • 10:27: What isn't defined is your own experience of that future branching.
  • 10:59: There are still other observers in your slice of reality for whom you are now is their past or future.
  • 11:51: So does the future already exist according to quantum theory?
  • 12:00: ... we ride the dice of Copenhagen into an unknown future or surf the splitting quantum multiverse into all futures of which you ...
  • 12:23: ... universe and what this might tell us about the reality of the past and future. ...
  • 13:41: And that fills the block universe past and future.

2020-10-13: Do the Past and Future Exist?

  • 00:05: Is the past erased and the future a void yet to be filled?
  • 00:09: Well the answer lies in between the past and the future - in the elusive, ever-moving eye-blink that we call the present.
  • 00:41: But today we’re definitely doing physics, because physics already tell us a lot about the reality of the past, future and present.
  • 00:55: The past is gone except in our memories, and the future is a blank slate ready to be written into the past.
  • 01:02: But interpreted some ways, physics suggests that the future and the past exist eternally, while the present is an illusion.
  • 01:27: ... as the forces that act between those particles, you could calculate all future and all past states of the ...
  • 02:16: ... agree on, and so everyone would also agree on what was past and what was future. ...
  • 04:50: There’s a name for this idea that all of time, future and past, sort of just exists as this atemporal structure.
  • 05:00: ... the current instant has a meaningful existence - the past is erased, the future still ...
  • 05:38: ... slice of the block was currently the present, and which sides were the future or the ...
  • 05:53: ... define whether two events happen simultaneously - the present, past, and future are relative ...
  • 07:35: OK, so the present seems definable - if only in the future.
  • 08:48: ... of you, things once in the future will become the present, and behind you the past becomes the present and ...
  • 09:16: Let’s get back to the question: what does all this say about the reality of the past and the future.
  • 09:23: Imagine that the future is created as the wave of the present sweeping out the block universe.
  • 09:40: The largest tilts are for things traveling at the speed of light, and these sweep out the future light-cone.
  • 09:47: In front of the future light cone is the region that is in the future for everyone, no matter what their speed.
  • 09:55: So is that the future that doesn’t exist until created by the evolving present?
  • 10:14: They have future light cones, simil to our, offset in space from ours.
  • 10:19: ... space beneath their future light cones defines all possible defines all possible definitions of the ...
  • 10:54: ... also hard to accept that only the past exists and the future doesn’t - at least in the sense of a growing block universe, again, ...
  • 11:09: ... block universe has a meaningful existence; or 2) if you don’t want the future to exist then you need to deny the existence of the present beyond your ...
  • 12:00: To rescue materialism without demanding a perfectly defined personal future we need quantum mechanics.
  • 12:24: ... need all possible realities to exist simultaneously and persist into the future. ...
  • 13:07: ... you the coolest dude in the block universe - that means past, future, and present - never mind that all of those are an ...
  • 13:16: At any rate, may your future lightcone contain only wonderful things.

2020-10-05: Venus May Have Life!

  • 13:56: So, Scott, I guess thanks for contributing to the future ascendency of humanity.

2020-09-28: Solving Quantum Cryptography

  • 11:53: To be secure against quantum attacks for the foreseeable future, McEliece would need an 8 Mb public key—8,000 times larger.

2020-09-21: Could Life Evolve Inside Stars?

  • 03:32: ... be discussing that more in the future, but for now the important thing is that these phase transitions could ...

2020-09-08: The Truth About Beauty in Physics

  • 13:34: So today we're covering our episode on the future circular collider and on how we know the composition of stars.
  • 15:11: ... on to the future circular collider - well actually Awesome Octagon dropped some knowledge ...
  • 16:15: I love the idea of future deep time.

2020-08-24: Can Future Colliders Break the Standard Model?

  • 00:28: ... big part of that is the Future Circular Collider, which, if it happens, will accelerate particles in a ...
  • 01:01: Today we’re going to discuss the incredibly ambitious plans for future colliders, and try to honestly evaluate their prospects.
  • 09:00: And so we come to the Future Circular Collider.
  • 10:11: The Future Circular Collider will cost 10s of billions over its life.
  • 10:34: The Future Circular Collider is the priority defined by the European Strategy Group.
  • 11:48: It’ll be an order of magnitude cheaper than the Future Circular Collider at an estimated 1.6 to 2.6 billion.
  • 13:48: ... contribution to purchase something like 10^30 protons to inject into the future circular collider - assuming it actually gets ...

2020-08-10: Theory of Everything Controversies: Livestream

  • 00:00: ... and what comes next also time reborn from the crisis in physics to the future of the universe which i have a very dog-eared copy right here it's ...

2020-07-28: What is a Theory of Everything: Livestream

  • 00:00: ... great search um and and possibly you know your your instinct for a future direction um i should also add here uh that we we're expecting lisa ...

2020-07-08: Does Antimatter Explain Why There's Something Rather Than Nothing?

  • 11:51: ... universe at all. Maybe it’ll come from CPT violations measurable only in future experiments. Or maybe it won’t—instead proving beyond a doubt that CPT ...

2020-06-30: Dissolving an Event Horizon

  • 06:31: ... leaves us with a strange situation - in the far distant future, even if all particles in the universe decay, we may be left with only ...
  • 13:27: ... but actually to the “conformal infinity” of the previous - so all the future infinite time of the previous added ...

2020-06-15: What Happens After the Universe Ends?

  • 00:45: ... goes like this: the infinitely far future, when the universe has expanded exponentially to to an unthinkably large ...
  • 07:00: Well, it may be that in the extreme far future our universe will contain only radiation.

2020-06-08: Can Viruses Travel Between Planets?

  • 06:32: Again, specialized instruments on future missions could detect viral material.

2020-05-18: Mapping the Multiverse

  • 03:25: Your so-called “future light cone” encompasses the parts of the multiverse you could possibly get to at less than light speed.
  • 03:53: Down becomes the future, because falling space drags us there faster than the speed of light.
  • 09:39: Extending the Kerr metric from ring singularity into the future leads to something else.
  • 10:00: The Kerr black hole also has a white hole in the past, but it has one in the future too.
  • 10:49: If you try to head back to the white hole, you won’t find it - you’ll only find a new black hole that lies in its future.

2020-04-28: Space Time Livestream: Ask Matt Anything

  • 00:00: ... seeing me I guess but usually there's this time lag like you're in my future I'm in your past this is the first time I think I've talked to you in ...

2020-04-22: Will Wormholes Allow Fast Interstellar Travel?

  • 04:08: ... for more details. But the TL;DR is that moving up means moving into the future and moving left means moving towards the black ...
  • 05:43: ... spacetime. If we instead take a slice a little further in the future we see the wormhole throat has narrowed in width and passing through ...
  • 06:35: ... accurately describes a non-rotating black hole if you just consider its future state where the wormhole is pinched off. But if you consider its entire ...
  • 13:26: ... a traversable wormhole. For the first many millennia of our star-faring future we’ll have to take the long way around the universe. But even if we ...

2020-04-14: Was the Milky Way a Quasar?

  • 12:56: ... going to witness the creation of a newborn Fermi Bubbles in the near future, we may be able to get new insights into the all-too frequent tantrums of ...

2020-03-31: What’s On The Other Side Of A Black Hole?

  • 08:44: ... see the singularity - that is manifest as an inevitable crushing future, in which the space around you becomes infinitely ...
  • 09:55: ... emerge from the past “white hole” traveling forward in time, or from the future black hole but traveling backwards in time. Which would just look like ...

2020-03-16: How Do Quantum States Manifest In The Classical World?

  • 15:50: ... that you mean any given version of you chosen randomly from all possible future timelines - then yes, chances are that version will die. The difference ...
  • 16:29: ... entropy to produce another Big Bang? In other words - if all possible futures occur in Many Worlds, do some of those lead to new Big Bangs. Well, the ...

2020-03-03: Does Quantum Immortality Save Schrödinger's Cat?

  • 06:57: ... consciousness is going to have to experience every single one of the bad future ...

2020-02-24: How Decoherence Splits The Quantum Multiverse

  • 02:20: Over time the histories of a quantum system separate to represent every possible future the laws of physics allow.

2020-02-18: Does Consciousness Influence Quantum Mechanics?

  • 03:12: It exists only as the possible outcome of a future measurement.
  • 12:49: ... now, one thing I can say with certainty is that your own future wavefunction includes a deeper dive into the quantum-classical divide, ...

2020-02-03: Are there Infinite Versions of You?

  • 03:19: ... positions, velocities, etc of all particles - perfectly determines the future history of any point with that ...
  • 03:45: ... they’re set just right then the future history of that region will be identical to our part of the universe, ...
  • 06:31: In such a chaotic system, even tiny differences in the starting conditions will lead to massive divergences in that future history.

2020-01-20: Solving the Three Body Problem

  • 00:20: ... in principle be used to calculate their locations at any distant time, future or past. I say “in principle” because the reality is not so simple. ...
  • 01:49: ... the state of the system at that time, no matter how far in the past or future. We call such a simple, exactly-solvable equation an analytic expression. ...
  • 03:18: ... of almost all starting configurations is dominated by chaotic dynamics. Future states are highly dependent on small changes in the initial conditions. ...
  • 06:20: ... can accurately predict the motion of the planets into the distant future or solve for millions of objects to simulate the formation and evolution ...

2020-01-13: How To Capture Black Holes

  • 11:07: ... mergers for just such a signature, and will be keeping a close eye on future ...

2020-01-06: How To Detect a Neutrino

  • 00:59: ... research program is centered around neutrinos, ♪ ♪ and the big one - the future one - is the DUNE ...

2019-12-17: Do Black Holes Create New Universes?

  • 07:16: ... Vilenkin proposed that if a universe lasts forever then in the distant future, quantum fluctuations of that near vacuum will cause black holes to ...
  • 15:00: It says that the majority will be right - if they predict that there will be a similar number of future generations as past generations.
  • 15:11: ... we'll eventually also be wrong ancient philosophers to some very distant future ...
  • 17:47: ... that Adam and Eve are the first two out of billions or trillions of future humans - therefore, odds are, they can have all the fun they want ...

2019-12-09: The Doomsday Argument

  • 00:05: How many will live in the future of our species?
  • 04:15: ... from the set of all actually existent observers (past, present and future) in their reference class." If a type of environment or type of universe ...
  • 06:07: ... say there are two possibilities for the future of humanity: in one, we’re destined to spread throughout the Milky Way ...
  • 06:46: Let’s apply the self-sampling assumption and imagine that you could have been any one of the past and future humans of our species.
  • 08:54: In the doomsday argument, the assumption is that our “reference class” is all past and future humans.
  • 09:03: ... if you define our reference class as all observers in our past and future evolutionary chain, then we could still be in the middle of that chain ...
  • 13:11: ... at this very moment brilliant and curious individuals are discussing the future of humanity, the nature of space and time, the weirdness of quantum ...

2019-12-02: Is The Universe Finite?

  • 11:57: The good news is that future missions will surely resolve it.
  • 14:10: ... that if there are to be trillions or quadrillions of humans in future space-faring civilizations, isn't it weird that we happen to be in the ...
  • 14:48: In order to save ourselves from imminent doom we may have to hope future generations are NOT in our reference class. Tune in next week.

2019-11-18: Can You Observe a Typical Universe?

  • 10:08: ... from the set of all actually existent observers (past, present and future) in their reference class." If there are a bajillion observers in the ...

2019-11-04: Why We Might Be Alone in the Universe

  • 14:57: At the beginning of the time travel episode I invited future time travelers to show up on set. None of you did.
  • 15:32: But Guy Frost has a better explanation - YouTube won't survive into the far future.

2019-10-21: Is Time Travel Impossible?

  • 00:00: If time travel turns out to be possible, I hereby invite future time travelers to join me on set I’ll post the address one year from today.
  • 00:19: ... travel stories are cool because both the past and future are somehow more interesting than the present and because everyone ...
  • 04:32: Travel through the “future” end and you’ll exit in the "past." So this all sounds straightforward enough.

2019-09-23: Is Pluto a Planet?

  • 13:33: Maybe at some point in the future, as we learn more about how different worlds form, astronomers will change the definition of planet again.

2019-09-16: Could We Terraform Mars?

  • 00:04: Humanity’s future is glorious.
  • 05:11: After all, these researchers only ruled out NEAR future technology.
  • 05:15: What about medium future?
  • 05:16: Far future?
  • 08:36: That’s definitely sounding far-far future.
  • 10:26: ... there’s our next snapshot of the far future of a terraformed Mars – brand new oceans green with photosynthesizing, ...
  • 15:08: So there’s our final image of humanity’s future on Mars: thousands of city-sized bubbles spread across the still-barren landscape.
  • 15:48: ... inspired by real aerospace technology, LEGO City Space aims to inspire future space explorers to imagine what role they can play to get us to the Red ...

2019-08-19: What Happened Before the Big Bang?

  • 09:56: Can eternal inflation last infinitely into the past as well as the future?
  • 10:14: Good material for the eternally expanding future library of PBS Space Time.

2019-07-25: Deciphering The Vast Scale of the Universe

  • 08:50: And hopefully our modern perspective will in turn be a gateway to future knowledge.

2019-07-18: Did Time Start at the Big Bang?

  • 09:52: ... cyclic cosmology it's even weirder because it postulates the infinite future boundary of an eternally expanding universe Looks like the Big Bang of a ...
  • 11:36: ... that draws on the holographic principle all things we'll discuss in the future as we travel beyond the beginning of ...

2019-07-15: The Quantum Internet

  • 09:45: ... the future, if entangled states can be maintained for long periods, it may be ...
  • 11:32: In a recent episode we talked about Thorium and the future of Nuclear Energy!
  • 15:03: Battlemechs, submarines, spaceships, DeLorean time machines - nuclear is probably the easiest option for the badass vehicles of the future.

2019-07-01: Thorium and the Future of Nuclear Energy

  • 15:29: ... next technological stage and send us to greater distances and further futures in space-time In a recent episode we talked about how black holes ...

2019-05-16: The Cosmic Dark Ages

  • 12:16: ... stelliferous era; Probably the only habitable epoch in the past and future history of space ...

2019-04-10: The Holographic Universe Explained

  • 00:04: Up, down, left, right, forward, back, past, future.

2019-04-03: The Edge of an Infinite Universe

  • 01:22: To review: the particle horizon defines the limit of the visible past, and there’s also cosmic event horizon defining the limit of the visible future.
  • 06:10: The boundaries themselves represent infinite distance and infinite past and future.
  • 07:05: ... converge to this point which represents all of space in the infinite future. ...
  • 08:15: ... a quantum field between two points at infinite distance – past and future - where he could define the state of the quantum vacuum in solvable flat ...
  • 15:06: Stay tuned for the final installment of the holographic principle in not-so-infinitely-distant future of spacetime.
  • 16:45: However our universe on its largest scales is not time symmetric - it's expanding, so the past looks very different to the future.

2019-03-28: Could the Universe End by Tearing Apart Every Atom?

  • 04:32: ... an emo party and get rid of regular massive pressure, after all, in the future dark energy will completely dominate the expansion so we have the energy ...
  • 06:03: ... idea for that scenario is called quintessence and it's something for a future episode. For today, let's push things to the limit: What if we make the ...
  • 12:53: ... wink out become black holes and then evaporate over an unthinkably long future. But maybe if you believe in phantoms it'll all be over much sooner when ...
  • 14:34: ... asks, "if dark energy changed in the past, can it also change in the future?" In fact, if it changed in the past then we expect it to change in the ...

2019-03-20: Is Dark Energy Getting Stronger?

  • 01:03: ... this is true, then our prediction for the future of our universe looks VERY different, and may involve the entire ...
  • 15:47: Richard also shared his dreams for the future of human space travel.

2019-03-13: Will You Travel to Space?

  • 01:08: Questions abound! Is there a future in these strange air-launch spaceships?
  • 01:16: And what other mad schemes lie in the future. And most importantly, when can WE go up?
  • 08:30: Perhaps in the future everyone who travels overseas will also become an astronaut. But I'm less patient than that When do WE get to go to space?
  • 10:10: But what about the far future?
  • 11:23: It could be a very exciting future.
  • 11:26: [RICHARD] It will be a very exciting future. And thank you for inspiring us with your knowledge, it's fantastic.

2019-02-07: Sound Waves from the Beginning of Time

  • 13:26: ... a fun one. To paraphrase: As the universe expands towards the infinite future, does that expansion outpace the probability of collapsing into a big ...

2019-01-16: Our Antimatter, Mirrored, Time-Reversed Universe

  • 10:54: ... the other hand broken T symmetry says that if you do this reversal the future won't perfectly mirror the past. One prediction of this T symmetry is ...

2019-01-09: Are Dark Matter And Dark Energy The Same?

  • 10:48: ... near the turnaround point presumably tens of billions of years in the future. ...

2018-12-20: Why String Theory is Wrong

  • 10:09: We will glimpse the mechanics and the implications of s-duality, as we look deeper into m-theory and holography in the future.

2018-11-07: Why String Theory is Right

  • 12:58: ... by M theory and in the discovery of AdS/CFT correspondence-- again, for future ...

2018-10-25: Will We Ever Find Alien Life?

  • 10:13: It also means we have a long, lonely future as one of the galaxy's only advanced species.

2018-10-18: What are the Strings in String Theory?

  • 10:29: We'll look into why in future episodes.

2018-10-03: How to Detect Extra Dimensions

  • 00:10: Fortunately, with the discovery of gravitational waves, we're now living in a science fiction future.

2018-09-20: Quantum Gravity and the Hardest Problem in Physics

  • 01:35: I'll save the solutions for future episodes.

2018-09-12: How Much Information is in the Universe?

  • 15:41: ... that a metaphor for quantum fluctuations in impossibly distant futures spontaneously generating a new big bang by pure chance, or do you mean ...

2018-08-23: How Will the Universe End?

  • 00:13: Nearly all of future history will be dark.
  • 03:48: So at this point in the universe's future history, the Age of Stars has passed and no starlight will ever shine again.
  • 08:25: If life manages to master this energy source, then its future history could be as ridiculously long as the Black Hole Era.
  • 11:54: ... perfectly distributed, entropy has peaked, and there's nothing for any future civilization to cling to, assuming they don't have technology so ...
  • 12:34: We'll explore these extreme futures of spacetime time in the near future of "Space Time." Before we get to comments, two things.
  • 13:28: Next, if anyone is interested in hearing two serious experts go into more detail about the far future of the universe, well, you're in luck.

2018-07-18: The Misunderstood Nature of Entropy

  • 08:59: ... not in equilibrium must increase in entropy, simply because at any future time, it's current microstate will most likely be one of the more common ...
  • 10:22: ... law of thermodynamics clearly distinguishes between the past and the future. ...
  • 10:45: ... we'll delve deeper into this in the future, but for now, please be careful to keep your number of accessible ...
  • 11:29: Check it out, because we'll be doing more stat mech and delving deeper into entropy in the future.

2018-07-11: Quantum Invariance & The Origin of The Standard Model

  • 10:26: And we'll come back to that in future episodes.

2018-06-13: What Survives Inside A Black Hole?

  • 13:53: ... years as Hawking radiation where it can be collected and giggled at by a future super-advanced ...

2018-05-23: Why Quantum Information is Never Destroyed

  • 00:44: These laws can be used to predict how the universe will evolve into the future.
  • 01:23: In a future episode, we'll see how this law might be broken by black holes.
  • 03:15: The idea that perfectly knowing the current state perfectly predicts all future states.
  • 03:20: But this sort of future determinism doesn't have to be time-reversal symmetric.
  • 03:25: It's possible for the future to be perfectly predictable by the laws of physics while the past is not.
  • 03:30: For example, what if many different configurations of particles in the present could converge on a single configuration of particles in the future?
  • 04:06: That future direction is deterministic, but now if we look at the final state, we see state C, but we don't know which of A or B led to it.
  • 05:19: ... Schrodinger equation perfectly predicts both the past and future evolution of a given wave function in any given environment, or in ...

2018-05-09: How Gaia Changed Astronomy Forever

  • 02:50: Location on this diagram can tell us about a star's mass, size, fusion activity, and even its past and future evolution.
  • 05:46: And mapping globular clusters and dwarf galaxy orbits also tells us about future interactions with the Milky Way.
  • 07:44: This is useful for future asteroid mining missions, and to identify potentially, Earth-threatening objects.
  • 08:33: Every dot of light in this picture is a star, with its past and future motion now known.
  • 09:50: It's a dismal future.

2018-05-02: The Star at the End of Time

  • 00:00: [MUSIC PLAYING] If our descendants or any conscious being is around to witness the very distant future of our galaxy, what will they see?
  • 01:02: How long can life survive into the far future?
  • 01:29: To know the future of life, we must understand the life cycles of the longest-lived stars in the universe.
  • 01:41: They have very, very bright futures and may even spawn a renaissance of life trillions of years from now.
  • 06:21: So what does this mean for the future of our galaxy and for any life that exists then?
  • 07:11: That dark future is inevitable, but for several trillion years, red dwarfs will be the last warm places in the universe.
  • 09:01: ... the real science of climate change, along with the implications for the future and the technology we'll need to fix ...

2018-04-04: The Unruh Effect

  • 05:54: It's like the projected future acceleration gives you a Rindler horizon in the present.
  • 10:42: Right now I have to jet but not too fast, lest I combust in a Fulling-Davies-Unruh thermal bath as I accelerate to that future point in space-time.

2018-03-28: The Andromeda-Milky Way Collision

  • 08:56: Astronomers in the distant future will see only a single featureless orb in the sky, and the next nearest galaxies will be very far and fast receding.

2018-03-15: Hawking Radiation

  • 05:04: It extends from far in the past to far in the future.
  • 05:44: A distant future observer sees radiation coming from the black hole.
  • 05:49: Hawking's imaginary path from the distant past to the distant future was brilliant.
  • 09:36: We'll look at its relationship to Hawking radiation in the future.
  • 11:41: We'll tackle all of these in future episodes.

2018-03-07: Should Space be Privatized?

  • 00:23: It looked like the future.
  • 00:43: Is this the best thing for the future of human space travel?
  • 08:37: And whether our aerospace executives are idealists or not, they have a huge influence on the future of our species.
  • 09:34: The future of human space travel is starting to look promising.

2018-02-28: The Trebuchet Challenge

  • 01:59: ... between two points, then we can keep track of the potential for future gains or losses of ...

2018-01-31: Kronos: Devourer Of Worlds

  • 06:55: And we'll need to take this into account for future searches.
  • 07:25: Future Gaia data will be used to search for rampaging outer planets around Kronos.
  • 07:36: ... be sure to keep you updated on future episodes of "Space Time." We recently discussed the gradual brightening ...

2018-01-10: What Do Stars Sound Like?

  • 07:45: Future planet hunting satellites, like Tess and Plato, will continue this work with higher precision and for many more stars.
  • 08:50: Woven into that music is knowledge of their mysterious depths and of the past and futures.

2017-12-13: The Origin of 'Oumuamua, Our First Interstellar Visitor

  • 08:10: The good news is that future telescopes will be much more sensitive.

2017-11-22: Suicide Space Robots

  • 00:56: Or in the case of the recent destruction of Cassini, to protect the solar system for future experiments.
  • 06:34: Where some spacecraft are destroyed to protect future science, in other cases their destruction is the scientific experiment.
  • 07:43: Deep Impact's sacrifice significantly furthered our understanding of comets and paved the way for future ill-fated landers like Philae.

2017-10-25: The Missing Mass Mystery

  • 10:51: The stuff of countless future solar systems is still riding the cosmic web, falling in from the darkest reaches of space time.
  • 12:55: Eliran Cohen suggests that, instead of presenting lame theories, we should travel 1,000 years into the future and bring back exact answers.

2017-10-19: The Nature of Nothing

  • 03:07: We'll come back to those when we talk about Hawking radiation in the future.

2017-09-28: Are the Fundamental Constants Changing?

  • 10:50: ... surveys with future generations of telescopes, more refined cosmological models, and better ...
  • 12:42: Last week, we talked about some possibilities for future advanced space telescopes.
  • 12:55: Well, it's funny you should mention that, because this is the future Space telescope that got cut from the last script due to length.

2017-09-20: The Future of Space Telescopes

  • 08:40: The future could lie in orbiting rainbows, an idea as creative as it sounds.

2017-08-30: White Holes

  • 03:16: The time that happens inside a black hole is not part of the past or future history of the outside universe.
  • 03:24: ... event horizon, including folding into it, happen infinitely far in the future. ...
  • 03:45: It now occupies an inevitable future time.
  • 03:55: ... the collapse, the future singularity comes into being, and in the past, well, there's just a ...
  • 04:20: From the point of view of the outside universe, the eternal black hole singularity exists both in the infinite future and in the infinite past.
  • 04:53: They compactify space time so that time bunches up towards the edges, and the borders correspond to infinite past and future.
  • 05:17: If we place an eternal black hole far to the left, then the future left boundary represents the black hole's event horizon.
  • 05:54: The once vertical contours of space are now time-like and flow inexorably towards the future singularity.
  • 06:21: Map into the past, and we see a time reflected version of our future black hole.
  • 07:03: Oh, it'll reach an event horizon, but only the event horizon of our future, where it plunges into a regular old black hole.
  • 07:20: The light rays from any crossing reach us infinitely far in the future, even if the black hole plunge began far in the past.
  • 11:42: We required that all paths be traceable through infinite past and future space, provided they don't hit the singularity.
  • 12:19: In the not too distant future, we'll investigate the reality of this mysterious parallel patch of space time.

2017-08-10: The One-Electron Universe

  • 01:01: ... bounces in time, eventually traversing the entire past and future history of the universe in both directions and interacting with itself ...

2017-07-12: Solving the Impossible in Quantum Field Theory

  • 11:46: In future episodes, we'll talk more about what is now the most complete description we have for the smaller scales of space time.

2017-07-07: Feynman's Infinite Quantum Paths

  • 14:55: The details might also make for a future episode.

2017-06-28: The First Quantum Field Theory

  • 15:00: And that's also something we'll get to but a bit further in the future.

2017-06-21: Anti-Matter and Quantum Relativity

  • 10:18: But there will be time for all of that in the future.

2017-05-17: Martian Evolution

  • 00:14: But there may be nothing at all familiar about these distant future space farers.
  • 00:47: At some point, perhaps soon, perhaps in the far future, we will try to colonize Mars.
  • 06:19: In all cases, these humans are able to sustain more activity with less oxygen. So we might expect future Martians to be incredible endurance athletes.
  • 08:32: Future Martians will be highly susceptible to earthly diseases.
  • 12:07: Perhaps future Homo martiansis will be amused by the fraction of Homo sapien's DNA that they have.

2017-05-10: The Great American Eclipse

  • 04:48: And so in the future, it won't be able to block out the entire sun anymore.

2017-05-03: Are We Living in an Ancestor Simulation? ft. Neil deGrasse Tyson

  • 04:22: ... argues that in the future it will be possible to simulate the action of all the neurons of the ...

2017-04-26: Are You a Boltzmann Brain?

  • 05:27: In the far future, the universe will reach maximum entropy.

2017-04-10: Here's Why I Love PBS

  • 00:57: Public media is an essential investment in the future of our society.

2017-04-05: Telescopes on the Moon

  • 09:51: I'm sending in some of my DNA, and I'll share the results with you on a future episode.

2017-03-29: How Time Becomes Space Inside a Black Hole

  • 05:13: Back out here in the regular universe, it's pretty obvious where the past and the future are.
  • 05:25: ... encompasses all of spacetime that could have influenced us, while that future light cone shows us the part of the universe that we might never hope to ...
  • 05:37: Which direction is the future?
  • 05:46: Our future light cone stares fixedly forwards, encompassing all spatial directions equally.
  • 05:56: Close to a massive object, your future is no longer at right angles to space.
  • 06:04: Send out a burst of future defining light rays, and they won't spread out evenly because they bend towards the gravitational field.
  • 06:18: Your future light cone and your time axis begin to blur together with the inward radial axis of the black hole.
  • 07:06: Our entire future light cone encompasses more and more of the event horizon.
  • 07:38: The outside universe exits our future light cone, which now just contains the singularity.
  • 08:54: We can try to move towards either source of light, down towards light from the black hole's past or up towards light from the black hole's future.
  • 09:15: ... a sense of past events in one direction-- the collapsing star-- and future events in the other, everything that fell into the black hole after ...
  • 09:26: But remember that future light cone actually just points towards the singularity.
  • 10:09: And all possible future directions lead radially inwards.
  • 10:12: In the same way that all world lines move towards the future in the outside universe, time is laid radially.
  • 10:24: The singularity becomes a future time, not a central place.

2017-03-22: Superluminal Time Travel + Time Warp Challenge Answer

  • 11:05: ... and PBS figure out what you guys are into and what you want for the future. ...

2017-03-01: The Treasures of Trappist-1

  • 07:01: ... Future spectroscopy from the James Webb Space Telescope will hopefully provide ...

2017-02-15: Telescopes of Tomorrow

  • 12:24: In that case, your causal future is uphill rather than downhill, which sounds exhausting.

2017-02-02: The Geometry of Causality

  • 00:05: The special theory of relativity tells us that one person's past may be another's future.
  • 05:33: ... every future tick of my clock, a signal arrives from the left and the right, and I ...
  • 08:35: ... from the origin to a nearby near-future event compared to a distant far future event on the same ...

2017-01-19: The Phantom Singularity

  • 09:25: We'll come back to that bit of awesome weirdness in a future episode.
  • 11:45: There, the causal roles of space and time switch places, and the central singularity becomes not so much a location in space but an inevitable future.

2017-01-04: How to See Black Holes + Kugelblitz Challenge Answer

  • 09:01: ... on the Penrose diagram, that's seen as the future light cone of everything below the event horizon leading to the ...

2016-12-21: Have They Seen Us?

  • 14:32: So a distant immortal observer, with a ridiculously good telescope, will detect photons from the falling monkey at all future times.
  • 17:29: The inward direction acts like the future direction.

2016-12-14: Escape The Kugelblitz Challenge

  • 03:41: Any observers within this extended event horizon are cut off from any future causal connection with the rest of the universe.

2016-12-08: What Happens at the Event Horizon?

  • 01:48: Would you see the entire future history of the universe playing fast forward at the instant that you crossed the event horizon?
  • 02:37: ... area encompassed by the so-called light-like paths defines all future events or space-time locations that we could potentially travel to or ...
  • 03:32: As it approaches the event horizon, its future light cone bends towards the black hole as fewer and fewer of its possible trajectories lead away.
  • 03:57: That makes it difficult to figure out what parts of the past and future universe the monkey can witness or escape to.
  • 05:24: ... number of time and space steps, only reaching us in our very distant future. ...
  • 05:56: The future cosmic horizon on the Penrose diagram is replaced with a plunge into a black hole.
  • 06:41: Once you're beneath the horizon, your future light cone still represents all possible paths that you could take.
  • 07:55: Its future light cone still includes a tiny sliver of the outside universe.
  • 08:07: It will, nonetheless, have experienced far less time than us when it emerges into flat space-time in our far future.
  • 08:15: ... reverse swan dive through the event horizon, watching the entire future history of the universe play out above it at that last ...
  • 08:50: There's no future universe spoiler promo.
  • 15:11: ... does have a definite position at all times and that position defines its future ...
  • 15:22: So if you know the position perfectly and you know the wave function, you can perfectly predict future locations.
  • 15:42: This uncertainty leads to the range of potential future trajectories, including trajectories through one slit or the other.
  • 16:16: Vacuum Diagrams correctly points out that to know the future trajectory of a particle, you only need position, not velocity, as I had stated.

2016-11-30: Pilot Wave Theory and Quantum Realism

  • 04:51: ... position and velocity at any point, you could figure out its entire future ...
  • 12:29: ... loved the discussions we've been having on the EM Drive and future episode ideas, not so much the embarrassing quark compilation-- damn ...

2016-11-02: Quantum Vortices and Superconductivity + Drake Equation Challenge Answers

  • 02:11: ... These findings will lead to some spectacular applications in the future, improving our understanding of superconductors and superfluids, and ...

2016-10-26: The Many Worlds of the Quantum Multiverse

  • 10:54: But of all those countless future branches of reality, some are going to be pretty amazing.

2016-09-29: Life on Europa?

  • 08:07: The observations taken with these instruments would then help NASA decide a promising site for a future possible lander.

2016-09-14: Self-Replicating Robots and Galactic Domination

  • 02:48: Because these may be the future of space development.
  • 04:08: ... verges on AI, we can now realistically project much further into the future. ...
  • 10:16: ... actually learned a lot about the future of robotics, including space robots and evolving self-assembling ...

2016-09-07: Is There a Fifth Fundamental Force? + Quantum Eraser Answer

  • 04:14: ... that is made regarding each of those photon's entangled partners in the future. ...
  • 07:41: And so it's way less out there than photons somehow knowing that in the future some conscious mind will know its path.

2016-08-24: Should We Build a Dyson Sphere?

  • 03:10: The crazy thing about the Dyson swarm is that we could probably start building one in the not too distant future.
  • 13:04: Those interference patterns hold information about future events.
  • 13:09: But we can't extract that information until those future events have occurred, and we can compare notes between the screen and detectors.

2016-08-17: Quantum Eraser Lottery Challenge

  • 04:56: Oh, I do get a signal-- nice work, future me.
  • 05:00: And that signal does contain the interference patterns from my future choices with perfect fidelity.

2016-08-10: How the Quantum Eraser Rewrites the Past

  • 09:21: As we'll see in the future, entangled particles really are able to influence each other instantaneously.
  • 12:15: A few of you pointed out that I neglected to mention certain known ends of the world that are coming in the distant future.
  • 12:41: Increasing atmospheric reflectivity for example, which is something we could do in the very near future, if we wanted to.

2016-08-03: Can We Survive the Destruction of the Earth? ft. Neal Stephenson

  • 00:56: We already talked a bit about the inevitability of giant impacts in the future and what we might do to protect ourselves.
  • 02:06: ... we really need is a world-renowned imaginer of possible futures, someone with a physics degree and recent expertise in rescuing humanity ...
  • 07:17: But then you've got to ask, what about future generations?

2016-07-27: The Quantum Experiment that Broke Reality

  • 04:16: ... photon has no idea where previous photons landed or where future photons will land yet each photon reaches the screen knowing which ...

2016-07-20: The Future of Gravitational Waves

  • 04:38: And question three, what will we see in the future?

2016-06-08: New Fundamental Particle Discovered?? + Challenge Winners!

  • 09:12: And how many times it would double in size in the future before matter no longer has any significant influence on expansion.
  • 09:20: More precisely, for how many past and future doublings of the scale factor are they both at least 10% of the energy content of the universe?
  • 11:27: You can take exactly the same approach to ask when in the future matter will only have a 10% contribution to the energy in that volume.
  • 11:53: ... inflation, and the infinite number of doublings the will happen in the future. ...
  • 13:29: We're come back to both of these ideas in future episodes of "Space Time." [MUSIC PLAYING]

2016-06-01: Is Quantum Tunneling Faster than Light?

  • 01:15: We'll talk a lot more about this awesome weirdness in the future.

2016-05-18: Anti-gravity and the True Nature of Dark Energy

  • 07:17: ... our far future universe, regular matter will have diluted away and will only have the ...

2016-05-11: The Cosmic Conspiracy of Dark Energy Challenge Question

  • 04:36: It'll go on to double in size approximately infinity times in the future.
  • 05:01: And for the vast majority of future doublings, regular matter will have diluted away and be an infinitesimal influence compared to dark energy.
  • 05:29: ... for how many of those infinite future doublings will regular matter and energy have any significant effect-- ...
  • 05:43: ... started to have a significant effect and how many billion years in the future will it take for matter to cease to ...
  • 06:30: That will disqualify you from this and future challenge questions.

2016-05-04: Will Starshot's Insterstellar Journey Succeed?

  • 00:09: Does this mean it's the future, finally?
  • 00:11: [MUSIC PLAYING] Do you remember when the future had spaceships?
  • 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.

2016-04-27: What Does Dark Energy Really Do?

  • 01:01: See, measuring the density of the universe is one way to determine its fate because the future expansion rate does depend on density.
  • 01:14: In fact, measuring the past expansion history should tell us the future expansion without ever having to count any galaxies.
  • 04:57: That something would be a high-mass energy content that could in the future cause it to recollapse.
  • 07:53: Let's take a mathematical ride into the far future, when the galaxies will be so far away that the density of the universe will be basically zero.

2016-04-20: Why the Universe Needs Dark Energy

  • 00:08: ... capacity to physically explore and at a time billions of years in the future. ...
  • 08:46: ... give us the insight we need to understand dark energy's effect on the future of ...

2016-04-13: Will the Universe Expand Forever?

  • 00:46: ... astronomical observations have revealed something even stranger-- the future expansion of the universe will be dominated by a mysterious influence ...
  • 03:53: ... the universe, there's some current expansion speed that would allow the future expansion rate of the universe to slowly grind to a halt over infinite ...

2016-03-23: How Cosmic Inflation Flattened the Universe

  • 07:57: We'll delve pretty deep into how this works in terms of general relativity on a future episode on dark energy.

2016-03-02: What’s Wrong With the Big Bang Theory?

  • 09:44: We'll get back to that on future episodes of Space Time.

2016-02-24: Why the Big Bang Definitely Happened

  • 02:15: ... the universe, and run the laws of physics forward in time to predict the future. ...

2016-02-17: Planet X Discovered?? + Challenge Winners!

  • 08:09: For those of you who missed out, we'll have more challenge questions in the future.

2016-02-11: LIGO's First Detection of Gravitational Waves!

  • 01:46: Today I want to talk about what exactly was seen, what it tells us, and what we can expect for the future.
  • 07:18: ... keep you up to date in future episodes of "Space Time." In a recent episode, we heated up the debate ...

2016-01-27: The Origin of Matter and Time

  • 09:09: Great questions for future episodes of "Space Time." For our recent episode on when time breaks down, you guys had some amazing questions.

2016-01-13: When Time Breaks Down

  • 07:51: We'll have time for all of this on a future episode of Space Time.

2015-12-16: The Higgs Mechanism Explained

  • 07:31: We'll come back to those in the future.

2015-12-09: How to Build a Black Hole

  • 10:05: On our clock, the singularity forms infinitely far in the future.

2015-11-25: 100 Years of Relativity + Challenge Winners!

  • 07:11: ... rocket fuel has less than 1% of the exhaust velocity of our pulsed future drive and so we need almost as much initial fuel mass as spacecraft ...

2015-11-18: 5 Ways to Stop a Killer Asteroid

  • 00:03: It's a scientific fact that the planet Earth will be hit by cataclysmic asteroids in the future.

2015-11-05: Why Haven't We Found Alien Life?

  • 09:33: ... stars and Earth-like planets that will ever form over the full past and future history of star formation in our universe, Earth is ...

2015-10-22: Have Gravitational Waves Been Discovered?!?

  • 09:24: ... we hear any more, we'll definitely tell you on a future episode of "Space Time." Last week, we talked about real spaceship ...

2015-10-15: 5 REAL Possibilities for Interstellar Travel

  • 00:03: The future of humanity is in the stars.
  • 01:11: So for argument's sake, let's say humanity's future is at stake, and we just discovered Earth 2.0 in the Alpha Centauri system.
  • 04:05: Although the 1963 test ban treaty says no space nukes, maybe we can make an exception for the future of humanity.
  • 09:50: Pure antimatter and the Kugelblitz drives, they're the starships of the far future.

2015-09-23: Does Dark Matter BREAK Physics?

  • 07:48: ... falling through a black hole's event horizon should see the entire future history of the universe happen in the instant before it crosses ...
  • 08:16: It would encompass all future time.
  • 08:21: The time interval that encompasses all future everything approaches zero, or at least the Planck time.
  • 08:30: ... anyway, the photons from the future universe will never catch up to the monkey because that light has to ...
  • 08:39: ... outside universe can be received at arbitrarily distance times in the future, only signals within its past light cone can catch up to ...

2015-07-02: Can a Circle Be a Straight Line?

  • 09:25: Indigo said that tracking time in the future might become a challenge if you have to consider relativistic effects.

2015-06-17: How to Signal Aliens

  • 04:49: ... maintenance missions inside the solar system become easier for us in the future, then this setup could serve as a really long-lasting ...
  • 07:11: More details about this will come in a future episode.
  • 11:04: And I hope the rest of you participate in future challenges.

2015-06-10: What Happens to a Helium Balloon in Freefall?

  • 00:08: ... about gravity and also to some other episodes we've got coming up in the future. ...

2015-05-27: Habitable Exoplanets Debunked!

  • 05:46: So for the foreseeable future, pinning down the actual habitability of true Earth analogs isn't happening.
  • 07:42: For future challenges, please make sure your subject lines match what we say exactly.
  • 09:52: It's a little too much to go into right now, but maybe we'll tackle it in a future episode.
  • 10:26: ... out the details, but it is highly likely that at some time in the future, the SI unit will reflect the physics that I articulated in this episode, ...

2015-04-29: What's the Most Realistic Artificial Gravity in Sci-Fi?

  • 09:00: Now, next week, we're going to poll you all about future episode topics.
  • 09:34: Once you accept that phrases like "the past" now and "the future" simply lack objective meaning.
  • 10:22: Maybe a future episode.
  • 10:30: Does quantum mechanics bring back free will since it attaches some inherent randomness to the future.
  • 10:33: Well, remember that there is no "the future." But that aside, I happen to think the answer is still no.
  • 10:40: ... DreamsOfMorpheus asks whether most physicists hold this view that the future already exists, knowing that Brian Greene has said similar ...

2015-04-22: Are Space and Time An Illusion?

  • 01:57: If two observers can't agree on the sequence of events, it means that at present, someone's past is in someone else's future.
  • 02:08: ... that there is no universal division of events into past, present, and future, which opens major philosophical cans of worms for things like free will ...
  • 03:34: ... B. In other words, even though we can't agree about past, present, future, time, or distance, we all appear to agree about ...
  • 05:52: And your future isn't merely predetermined.

2015-04-15: Could NASA Start the Zombie Apocalypse?

  • 03:24: Plus, the future of space travel won't just be government space agencies.

2015-03-11: What Will Destroy Planet Earth?

  • 04:45: Now, as always, it's prudent to see whether that answer holds up under future simulations.
  • 06:07: ... Ripless future is also within Planck's margin of error and The Big Rip scenario has ...

2015-03-04: Should We Colonize Venus Instead of Mars?

  • 01:53: That means better protection from space radiation and meteorites for our enterprising colonizers and their future cities.

2015-02-18: Is It Irrational to Believe in Aliens?

  • 04:11: Our more advanced future selves might need even less time to do this.
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