Search PBS Space Time


2022-12-14: How Can Matter Be BOTH Liquid AND Gas?

  • 07:27: ... first we might think this pressure has no effect because liquids are incompressible, but look at the phase diagram: At ...
  • 13:25: ... atmosphere is almost entirely carbon dioxide, creating a greenhouse effect that heats the surface to more than 700 K. Combined with the extreme ...

2022-12-08: How Are Quasiparticles Different From Particles?

  • 02:25: It has an effective positive charge due to the charge of the nucleus not being properly canceled by electrons in that location.
  • 02:34: It even has an effective positive mass.
  • 11:26: ... momentary convergence of positive charge are jostled so much that this effect is tiny But if the metal is really, really cold - like, near absolute ...
  • 11:47: ... sets up a sort of resonance in the vibrational modes of the lattice, effectively binding pairs of electrons ...

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

  • 07:14: The details deserve their own episode, but the important thing to know is that it’s a short-range effect.

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

  • 11:54: ... cross the galaxy at 10% light speed, this delay will have basically no effect on cosmological ...
  • 17:49: He showed that instant collapse of entangle wavefunctions led to crazy FTL-like effects, and so thought it couldn’t be real.
  • 18:00: Of course we now know these effects to be very real features of entanglement.
  • 18:34: They imagined waves traveling from both cause to effect and from effect to cause.
  • 18:41: If there are multiple possible effects, then the cause gets to choose between them by picking from the time traveling signals.

2022-10-26: Why Did Quantum Entanglement Win the Nobel Prize in Physics?

  • 02:26: ... you really do seem to have an effect that travels faster than light, with the ball on the moon switching ...

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

  • 02:21: ... that the wavefunction can be distorted in different ways that have no effect on the laws of nature. It’s just not as straightforward to say exactly ...

2022-10-12: The REAL Possibility of Mapping Alien Planets!

  • 01:25: ... radio signals from telescopes all across the planet,   effectively giving us a planet-sized telescope with a tiny diffraction limit. ...
  • 18:29: ... particle rest mass. The energy   liberated in the interaction effectively raises the temperature of that tiny patch of space, and   ...
  • 19:23: ... these changes the strength of that force, which is the right effect. ...

2022-09-28: Why Is 1/137 One of the Greatest Unsolved Problems In Physics?

  • 02:36: ... Sommerfeld who managed to explain  the discrepancy by including the effects of Einstein’s still-new relativity, as well as the fact that the energy ...

2022-09-14: Could the Higgs Boson Lead Us to Dark Matter?

  • 01:40: We see its effect in the way galaxies move and in how the universe on the largest scales evolves.

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

  • 17:12: So the answer is yes, but the effect isn’t noticeable until a few billion kelvin in temperature.

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

  • 00:00: ... way the universe is expanding - there’s some kind of anti-gravitational effect that’s causing the expansion to accelerate. We don’t know what it is - ...
  • 01:41: ... For today, I need to ask you to accept that the anti-gravitational effect of dark energy is due to it having negative pressure. That’s ...
  • 02:31: ... thing about dark energy is that, on top of the anti-gravitational effect of its negative pressure, it also produces regular attractive gravity ...
  • 03:33: ... worth of matter. That’s such a tiny amount that it doesn’t have any real effect in places where there’s even a smattering of regular matter - like ...

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

  • 04:16: ... example solids are rigid having effectively infinite viscosity; liquids are viscous and are incompressible; gasses ...

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

  • 05:11: This type of effect that made Einstein and company so uncomfortable.

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

  • 07:38: ... parity are intimately tied. I just told you that you can undo the effects   of using the left-hand rule by placing a minus sign in front of ...

2022-06-22: Is Interstellar Travel Impossible?

  • 00:01: But is it so deadly that we’re effectively imprisoned in our solar system forever?

2022-06-15: Can Wormholes Solve The Black Hole Information Paradox?

  • 11:25: ... there’s just a single black hole,   you’d expect their effect to disappear, but amazingly, the math stays different. The ...

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

  • 18:10: ... a cosmological constant.   There would indeed be an additional effect  due to the tiny vacuum energy inside   the galaxy. However the ...

2022-05-04: Space DOES NOT Expand Everywhere

  • 00:52: ... know the effect of cosmic expansion on the most enormous scales, but what about the here ...
  • 11:59: ... increases as the universe expands. But again, this will never have any effect inside bound gravitational systems. Its effect only manifests when ...
  • 12:56: ... of space means the universe can and probably will expand forever with no effect on this little bubble of relatively static space that we call the Milky ...

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

  • 15:24: ... days when we didn’t have dark energy. If you just consider the positive effect of gravity, then the spatial geometry dictates the final fate. But dark ...
  • 16:10: ... camera. It would also have such low energy that it wouldn’t have any effect on any sane ...

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

  • 02:33: But the effect is the same: no events that happen now beyond that horizon can ever be seen.

2022-03-23: Where Is The Center of The Universe?

  • 03:04: General relativity can be used to calculate the spacetime curvature produced by the Earth or the Sun to determine their gravitational effects.
  • 16:07: Without that recycling Earth would have frozen due to the absence of greenhouse effect.

2022-03-16: What If Charge is NOT Fundamental?

  • 10:45: Weak isospin is effectively the charge of the weak force, carried by these W bosons.

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

  • 04:42: ... named because the Doppler effect is only  produced by the component of the star’s velocity that’s ...

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

  • 10:09: ... other way to spot cosmic strings also  relies on a gravitational effect: gravitational   lensing - which is the warping of background ...

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

  • 06:04: ... to model the effect of wave function collapse, Ghirardi, Rimini, and Weber added a ...
  • 11:09: ... scientists working in Trieste, Italy tried to measure this radiation effect. They put an 8-by-8 cm germanium crystal in a cryostat and carefully ...
  • 11:50: ... predicted effect was so tiny, researchers had to go underground to try to minimize as ...

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

  • 00:03: ... however observationally there's absolutely no difference in the effect uh and actually this gets us to uh another question by return deuter ...

2022-01-27: How Does Gravity Escape A Black Hole?

  • 01:55: When you use those equations to calculate the speed of various gravitational effects, they also turn out to be the speed of light.
  • 07:21: ... the broader region occupied by both of the electrons, and their summed effect leads to a repulsive force between the ...
  • 08:54: To experience the gravitational effect of a massive object, the information about the presence of that mass does have to be able to reach you.
  • 09:12: ... event horizon, but we can see its past mass, and it’s the gravitational effect of the past mass that we actually ...

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

  • 05:02: In the simplest type of N-body simulation you need to compute the effect of every particle on every other particle.
  • 06:00: ... together and consider only  their summed gravitational effect. ...
  • 06:43: ... now you have a shortcut - when you calculate  the effect from distant locations, you don’t do it for each particle - instead you ...
  • 08:35: ... they  track tracer particles within the fluid - those particles effectively make up a constantly shifting ...

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

  • 12:12: ... we can't identify a single Dyson sphere's effects around individual stars at distant galaxies. But what if a civilization ...
  • 13:19: And about the effect on the enclosed star due to a partial Dyson sphere.

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

  • 00:02: ... in the light of distant quasars due to this gravitational lensing effect all of this in preparation for the [Music] lsst survey which is ...

2021-11-17: Are Black Holes Actually Fuzzballs?

  • 04:49: ... the black hole using pure general relativity but then analyze its effect on the surrounding quantum fields, which only worked if the gravity at ...
  • 09:39: ... element of the fuzzball paradigm is the discovery that quantum gravity effects might not just be important at the center of the black hole but instead ...
  • 09:52: The ability for strings to maintain structure in this extreme gravity comes down to an effect specific to string theory called fractionation.
  • 10:10: ... merge a large number of strings, the tension of the resulting object is effectively smaller than for each individual string - proportional to the number of ...
  • 10:50: Light trying to escape would still be massively redshifted - sapped of energy by the gravitational field - rendering the object effectively black.
  • 11:02: All classical effects of black holes from general relativity would be preserved.

2021-11-10: What If Our Understanding of Gravity Is Wrong?

  • 01:39: ... hunting for an alteration to our theory of gravity that can explain the effect of dark matter without the actual ...
  • 04:17: ... you only need to tune a single parameter -  which is effectively the minimum acceleration - to get the correct rotation curves for nearly ...

2021-11-02: Is ACTION The Most Fundamental Property in Physics?

  • 10:26: ... up kinetic minus potential energy nor the proper time. Instead, it effectively calculates the phase shift that a particle picks up along each path ...

2021-10-20: Will Constructor Theory REWRITE Physics?

  • 08:57: That means their states could be correlated in a way that allows them to have an apparently non-local effect on each other.

2021-10-13: New Results in Quantum Tunneling vs. The Speed of Light

  • 05:09: ... a thick enough barrier, this ‘Hartman effect’ can effectively teleport real, physical matter between locations faster ...
  • 05:37: So in our previous tunneling episode, we offered an explanation for why this effect doesn’t break relativity.
  • 10:16: ... from the early 80s and on seemed to agree that the Hartman effect is real, but interpretation of the results suffer from some of the same ...
  • 11:50: ... the results are still relevant for the faster-than-light Hartman effect, because the spin-based clocks that they were working with should still ...

2021-10-05: Why Magnetic Monopoles SHOULD Exist

  • 07:09: ... string the electron passes - and that would actually have a noticeable effect on the path of the ...
  • 10:24: There should be no noticeable effect even if the direction of the Higgs field changes smoothly across space.

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

  • 05:59: ... each other. In that case they actually cancel each other out and you effectively have no photons. Mathematically, a half-cycle phase shift corresponds to ...

2021-09-15: Neutron Stars: The Most Extreme Objects in the Universe

  • 11:29: ... act as spin-0 or spin-1 particles.   Some of our fermions effectively become bosons - which means they can do some pretty crazy ...

2021-09-07: First Detection of Light from Behind a Black Hole

  • 12:54: ... might be detectable from great distances - as in, could we see the effects of FTL communication from distant alien ...

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

  • 06:28: ... the Many Worlds hypothesis - those other worlds by definition have no effect on our own. That’s true as long as the Schrodinger equation is perfectly ...
  • 07:50: ... would make it possible to achieve some pretty crazy science fiction effects. ...
  • 08:08: ... It’s almost like the universe conspires to prevent any superluminal effects. ...

2021-08-03: How An Extreme New Star Could Change All Cosmology

  • 15:55: ... asks whether magnetic fields have any measurable effect on the orbits of stars around the galaxy. Not directly. The galactic ...
  • 17:08: ... So the answer is no, although magnetic fields do have important effects on scales from stars to galaxies - they’re still much, much weaker than ...

2021-07-21: How Magnetism Shapes The Universe

  • 08:02: ... is sort of the sum of the circular polarizations - gets rotated in an effect called Faraday ...
  • 09:17: We did a whole episode on this cool effect if you want to learn more.
  • 14:38: The anomalous Zeeman effect was discovered not by Zeeman but by an Irish Physicist, Thomas Preston, and Preston never seems to get any credit.

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

  • 02:20: And the complexity of the sum has no effect on the motion of the individual.

2021-07-07: Electrons DO NOT Spin

  • 02:25: ... experiment with the iron cylinder is called  the Einstein de-Haas effect, first performed by, well, Einstein and de-Haas in 1915. It wasn’t the ...
  • 03:20: ... reasonable. But then came the anomalous  Zeeman effect. In some cases, the magnetic field causes energy levels to split even ...
  • 04:40: ... the conservation of angular momentum like  in the Einstein de-Haas effect, and it also gives electrons a magnetic field. An electron’s  spin ...

2021-06-23: How Quantum Entanglement Creates Entropy

  • 11:00: ... and classical world.   Our capacity to observe quantum  effects like superposition   depends on being able to access the ...

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

  • 04:49: ... uncertainty principle is far more   fundamental than just the effect of disturbing the  system that you’re trying to measure - and ...
  • 06:02: ... if enclosed in a system a photon   creates what we call effective mass, according to Einstein’s famous equation. The ...
  • 06:39: ... uncertainty is. Space is stretched   by a factor equal to the effective mass times the gravitational constant divided by c^2.   ...
  • 07:48: ... smaller than one-Planck-length.   But that photon has enough effective mass to produce a black hole with a Planck-length event   ...

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

  • 11:29: Some sci-fi writers like to present Kessler syndrome as an impassable maelstrom, a giant space blender, effectively imprisoning us on the Earth.

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

  • 11:54: The effect of such a bias is that you can tend to interpret all evidence in the light of that particular hypothesis.
  • 12:00: It’s called confirmation bias, and its effect is insidious.

2021-05-11: How To Know If It's Aliens

  • 14:48: ... time travel impossible - and it’s been speculated that quantum gravity effects will come into play for things like warp drives, whose superluminal ...

2021-04-21: The NEW Warp Drive Possibilities

  • 02:38: That effectively means that it’s impossible to observe a massive object cross this speed barrier.
  • 13:38: We’re calling this version the Falco drive, and it’s guaranteed to be literally exactly as effective as any warp drive ever constructed.
  • 13:55: Okay, onto today’s comments we’re covering two episodes - there’s the quantum Zeno effect and the recent result from Fermilab’s muon g-2 experiment.
  • 16:15: OK, onto the quantum Zeno Effect, and the idea that you can freeze a quantum system by observing it.
  • 16:54: For Flensdude the quantum Zeno effect reminds them of a poem composed by the Norse god Odin.
  • 17:54: ... Turner asks the real question: If the Quantum Zeno Effect plays a role in birds' ability to see magnetic fields, then according to ...

2021-04-13: What If Dark Matter Is Just Black Holes?

  • 07:44: ... around the black hole acts like a lens, magnifying the source in an effect called ...

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

  • 01:15: ... its motion simply by looking at it, through the aptly named quantum Zeno effect. ...
  • 01:27: ... quantum Zeno effect predicts that certain quantum events - like the electrons moving between ...
  • 01:43: But first, let’s see if the Quantum Zeno Effect can save us from being shot by a quantum arrow.
  • 04:41: ... and keep resetting it back again through the magic of the Quantum Zeno Effect. ...
  • 05:23: ... decay, even chemical reactions The basic idea of the quantum Zeno effect was first proposed by Alan Turing, but it got a full theoretical ...
  • 07:02: ... arrows and presumably also electron transitions via the Quantum Zeno Effect. ...
  • 07:47: ... studies have claimed successful observation of the quantum Zeno effect, including various studies of atomic energy levels, as well as the ...
  • 08:02: ... even been proposed that the quantum Zeno effect plays a role in the photochemical reactions that give birds their ...
  • 08:13: Quantum Zeno effect verified?
  • 08:29: ... it’s not the abstract act of measurement that causes the quantum Zeno effect, but rather it’s a physical consequence of interacting with the ...
  • 09:30: ... that it’s perturbation, not measurement, that causes the quantum Zeno effect by demonstrating that with the right type of “jiggling” a quantum ...
  • 10:38: ... to get a full quantum Zeno effect - a perfect freezing of your electron or quantum arrow - you need to ...
  • 11:04: Obviously we’ve talked about decoherence and many worlds before, but let’s talk about what the quantum Zeno effect looks like in this picture.
  • 11:12: The effect should still exist, because Many Worlds gives the same predictions as Copenhagen.
  • 12:05: The quantum Zeno effect appears to be very real - but its interpretation is still hotly debated.

2021-03-16: The NEW Crisis in Cosmology

  • 08:03: ... when we put telescopes in space - above   the blurring effect of Earth’s atmosphere it’s possible to make better position ...

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

  • 01:26: But the weird thing is that despite these incorrect assumptions, the effects that these guys predicted have proved very real.
  • 04:27: ... from it can be sapped of ALL energy - redshifted so the wavelength is effectively ...
  • 10:19: ... because of two effects: your clock is ticking faster than clocks in the gravitational field, and ...
  • 11:02: But for you, tracking this from a distance, the effective speed of light decreases downwards, because time slows and space stretches.

2021-02-24: Does Time Cause Gravity?

  • 06:42: By the way, two of my favorite physics channels have great, slightly different explanations of this effect.
  • 07:48: But light DOES bend in a gravitational field - astronomers see it happening all the time in the effect we call gravitational lensing.
  • 08:04: So we’d better understand the effect of gravity on the path of light.
  • 10:28: These could be found in the gravitational wave background, but also indirectly through their effect on the cosmic microwave background.
  • 10:56: ... inflation it’s believed that quantum gravitational effects would have been very important, so if we can get any type of signal from ...

2021-02-17: Gravitational Wave Background Discovered?

  • 00:00: ... field changes with distance from the earth and there's also the tidal effect the direction of down shifts slightly from one point to the next but ...

2021-02-10: How Does Gravity Warp the Flow of Time?

  • 02:40: And today we’ll explore the origin of this effect.
  • 03:07: ... convincing you that time must run slow in a gravitational field - an effect we call gravitational time ...

2021-01-12: What Happens During a Quantum Jump?

  • 10:47: They explain this non-instantaneous quantum transition in terms of something called the Quantum Zeno Effect.

2020-12-22: Navigating with Quantum Entanglement

  • 06:14: ... can lead to all sorts of weird effects, including an apparent faster-than-light influence - measure the property ...
  • 09:45: It’s strange to think of quantum effects being relevant in living organisms.

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

  • 00:21: ... maximum entropy, and its eternal exponential expansion drives it to effective utter emptiness and absolute ...
  • 05:27: ... failed to incorporate the effects of Albert Einstein’s relativity theory, which predicted that the world ...

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

  • 04:13: ... non-random state will tend to become more random. It’s a statistical effect - it’s possible for small fluctuations to happen, local drops in ...
  • 11:16: ... matter whether they were generated in our brains or in the big bang. The effect is the same: effective free will, in the sense that our choices have ...

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

  • 01:14: ... decision, is the inevitable result of the long chain of cause and effect that came before ...

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

  • 03:36: ... right direction to see emergent phenomena like the sequence of cause and effect, evolving patterns of structure and information, entropy, and even our ...
  • 08:29: ... that’s the effect of Einstein’s special relativity - space and time tilt into each other, ...
  • 09:04: ... the effect is tiny, but the “present” at the edge of the observable universe veers ...

2020-10-05: Venus May Have Life!

  • 01:25: See, Venus has what we call a runaway greenhouse effect.
  • 03:44: There are lots of ways to do this - for example seeing the effect on a star’s light as it passes through its own planets atmospheres.
  • 11:04: ... much more sensible critters that existed prior to the runaway greenhouse effect. ...

2020-09-28: Solving Quantum Cryptography

  • 05:12: Still effectively impossible Shor’s algorithm is potentially exponentially faster.

2020-09-01: How Do We Know What Stars Are Made Of?

  • 07:49: In astrophysics, these sort of messy, competing effects rule the universe.

2020-08-17: How Stars Destroy Each Other

  • 05:23: This is all stuff we’ve talked about before - be we haven’t seen the effect on a hapless companion star of having one of these as its binary partner.
  • 11:50: ... prevents the singularity from really forming - but quantum gravity effects would not kick in soon enough to save the neutron ...

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

  • 00:00: ... be and those things didn't happen now you can always add epicycles effectively and they've added a tremendous number of epicycles so to the the ...

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

  • 00:00: ... is this infinitesimally light infinitest small particle that has no effect on anything else and in quantum mechanics the observer actually ...

2020-07-20: The Boundary Between Black Holes & Neutron Stars

  • 14:33: ... universe where hydrogen and anti-hydrogen came into contact to explosive effect. ...

2020-06-22: Building Black Holes in a Lab

  • 06:33: ... particles-slash-vibrations themselves acquire negative energy. This effect on the black hole is called the backreaction of the Hawking radiation - ...
  • 09:19: ... analogs are, Hawking radiation is ultimately a quantum mechanical effect. Deeper insights may require an analog quantum black hole. Enter the ...

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

  • 08:19: Well yeah, but those particles were effectively massless also.
  • 09:05: In the first tiny fraction of a second we can think of the universe as being full of effectively or actually massless particles.

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

  • 07:38: ... compelling way to transport viruses because the mechanism is especially effective for very small water droplets - of the kind that viruses tend to ...
  • 15:22: ... the Casimir effect is thought to be due to an alteration in the vacuum energy between a ...
  • 15:49: ... Casimir effect depends strongly on the material of those plates - its conductive and ...

2020-05-27: Does Gravity Require Extra Dimensions?

  • 06:36: There are different ways of thinking about how compactified extra dimensions can effect the strength of gravity.

2020-05-18: Mapping the Multiverse

  • 02:26: This leads to weird effects.
  • 12:23: That pressure produces its own gravitational effect on par with the black hole itself, accelerating the streams further.
  • 12:31: The result is an exponential runaway effect.
  • 13:13: ... massive tension, or negative pressure that produces an antigravitational effect. ...

2020-05-11: How Luminiferous Aether Led to Relativity

  • 05:08: ... waveforms are out of phase and so cancel out. We see exactly the same effect in a pair of expanding ripples on the surface of ...

2020-05-04: How We Know The Universe is Ancient

  • 11:07: ... precise value of 13.8 billion years, you need to take into account the effect of matter slowing down expansion through its gravity and also the effect ...
  • 12:09: ... story short, the accelerating effect of Dark Energy counters the slowing effect of gravity to ultimately give ...

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

  • 00:00: ... you guys are you guys are flicking through so fast favorite Mass Effect game there were multiple Mass Effect questions actually including let ...

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

  • 09:17: ... violated in some cases - for example in dark energy and in the Casimir effect. ...
  • 09:39: The casimir effect is by far the most popular speculative mechanism for opening a wormhole.
  • 09:44: ... energy density relative to surroundings. Unfortunately, the Casimir effect is very, very weak, and the negative energy density it produces is ...

2020-03-24: How Black Holes Spin Space Time

  • 04:11: ... fact, how can any effect of gravity extend from beneath the event horizon? In fact it sort of ...
  • 11:31: ... If we happen to be along the paths of one of these jets, relativistic effects massively magnify its brightness. We see these as gamma ray bursts from ...

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

  • 05:32: ... spooky action at a distance, and we now know that this is a very real effect, even though you can’t actually transfer useful information this way. But ...

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

  • 08:54: We lost the ability to distinguish the effect of multiple histories.
  • 09:18: ... to the decoherence hypothesis, it’s not really some magical effect whereby the wavefunction “knows” that it has been observed and so ...

2020-02-11: Are Axions Dark Matter?

  • 08:05: ... virtual quarks which then decay into photons - the so-called Primakoff effect. This would look like an axion turning into a photon - typically in the ...

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

  • 03:38: The properties of each region are effectively random - set in the beginning of the universe by quantum processes.
  • 14:32: How can particles scatter off each other without some notion of cause and effect or location?

2020-01-27: Hacking the Nature of Reality

  • 10:47: ... - it seems like an emergent set of relationships - what we call an “effective” theory - but it turns out that it has led to deep insights that even ...
  • 15:10: ... collide, and LIGO only sees the merger in the last second, so the effect would be ...

2020-01-20: Solving the Three Body Problem

  • 12:21: ... Because the series converged, which successive terms diminished to effectively nothing, so in principle the equation could be written out on paper. ...

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

  • 03:38: ... the event horizon of the black hole, it forms a new region of spacetime, effectively creating a new ...
  • 06:48: ... addition, gas needs to be shielded from the heating effect of other stars - and that seems to require the presence of tiny ...

2019-12-02: Is The Universe Finite?

  • 02:19: And that's even accounting for accelerating effect of a constant dark energy.
  • 12:43: Effective learning is about problem solving.

2019-10-21: Is Time Travel Impossible?

  • 05:42: ... have argued that we already produce this in the Casimir effect, in which the energy of the vacuum is lowered between two nearby ...
  • 06:42: But the energy conditions don’t have a really fundamental basis, and they're seen to be violated in some cases – like with the Casimir effect.
  • 09:34: And yet most physicists still think it’s impossible because time travel threatens the common-sense chain of cause and effect.

2019-10-15: Loop Quantum Gravity Explained

  • 14:59: We do see this effect in the light from gravitationally lensed quasars and supernovae.

2019-10-07: Black Hole Harmonics

  • 08:34: That means it seems very likely they really detected the overtone, but to effectively eliminate doubt we’d want more observations.
  • 13:43: Effective learning is about problem solving.

2019-09-23: Is Pluto a Planet?

  • 15:45: ... a rotating habitat or cylinder in space can produce the effect of gravity for its inhabitants, but without an actual powerful ...

2019-09-16: Could We Terraform Mars?

  • 01:45: But it also means almost no greenhouse effect.
  • 09:27: Nonetheless, our descendants could see a Mars with sufficient air pressure and greenhouse effect to allow liquid water to persist on the surface.
  • 18:17: It's a very cool effect.

2019-09-03: Is Earth's Magnetic Field Reversing?

  • 05:03: These flows are then twisted into helixes by the coriolis force – the same effect that produces hurricanes on Earth’s surface.
  • 05:10: ... produces Earth’s magnetic field through a process called the dynamo effect – or so most scientists accept these ...
  • 05:42: ... key is that the dynamo effect doesn’t really create a magnetic field from scratch – instead it ...
  • 07:13: Well, actually ANY weak field – even random bits of field – for example thermal fluctuations - are enough to initiate this runaway effect.
  • 07:42: The field produced by this effect looks pretty organized, but it’s not as clean as a bar magnet.
  • 10:18: ... simulations show that the dynamo effect should indeed produce a large-scale dipole field that spontaneously ...
  • 10:40: They simulate the dynamo effect in the outer core quite nicely, and even reveal spontaneous polarity flips.

2019-08-06: What Caused the Big Bang?

  • 02:43: Mostly, the stuff in the universe pulls the universe back together; resists the expansion with a positive gravitational effect.
  • 02:50: But there's one type of energy that can have an anti gravitational effect.
  • 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.

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

  • 02:49: ... trigger at least one more fission That's a chain reaction, a domino effect That can be a runaway chain reaction in which each split nucleus causes ...
  • 15:29: ... Relative to the galaxy as a whole and how does this influence their effect on the ...
  • 16:59: ... a rotating massive object in the case of a black hole it's most obvious effect is that it changes how closely an objects can orbit the black hole in a ...

2019-06-20: The Quasar from The Beginning of Time

  • 01:10: ... like being on another planet. I can already feel the effect of the thinner atmosphere. My natural impulse, bizarrely, is to hold my ...

2019-05-01: The Real Science of the EHT Black Hole

  • 08:51: On the opposite side of the black hole the emission is dimmed by the same effect.

2019-04-24: No Dark Matter = Proof of Dark Matter?

  • 00:03: ... journal Club we'll look at the papers that reveal this discovery the effect of dark matter who was first noticed in 1933 when the legendary Swiss ...

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

  • 14:49: Every particle, every gravitational effect in the bulk is represented by quantum fields on an infinitely distant surface.

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

  • 00:25: ... gravitational field is plenty strong enough to resist the minuscule effect of dark energy it's in the vast tracts of space between galaxy clusters ...
  • 03:05: ... the universe to cause it to recollapse. In fact for regular matter the effective density is much higher than the effective pressure the ratio pressure ...
  • 05:32: ... In fact, any equation of state parameter less than -1/3 would cause that effect. It would mean the stuff is diluted away a little less quickly than the ...
  • 09:26: ... event horizon is quite inside the Milky Way just yet, just that the effect of phantom energy is stronger than the gravity binding the stars ...

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

  • 02:32: We see its effect in the rotation and movement of galaxies and in the bending of light due its space-warping gravity.
  • 08:32: If UV and X-ray light track each other perfectly, there would be no way to differentiate the effects of distance and intrinsic energy output.
  • 08:41: Both effects would cause the UV and X-ray light to brighten or dim in the same way.
  • 12:06: It’s not strong enough to have any effect on the space inside a galaxy, so the Milky Way, and certainly the solar system are safe.

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

  • 03:21: ... a lovely book called The Overview Effect which is infused with all these people who've been into space. And also, ...
  • 04:57: ... travel and satellites in space, is a desire to bring the environmental effect down to an absolute minimum. So we can put somebody into space for about ...

2019-03-06: The Impossibility of Perpetual Motion Machines

  • 03:26: Machines of the second kind claim to be able to tap reservoirs of energy that are already evenly spread – effectively reversing the growth of entropy.
  • 09:05: ... be possible to create an energy gradient, for example with the Casimir effect in which plates are pulled together by lowering the zero-point energy ...

2019-02-20: Secrets of the Cosmic Microwave Background

  • 07:42: ... Energy results in positive curvature due to its positive gravitational effect On the other hand an expanding universe with no energy would have ...

2019-01-24: The Crisis in Cosmology

  • 01:42: ...the rate of expansion of the universe, combined with the gravitational effect...
  • 14:44: ...if the effect of dark matter was due to this dark fluid.

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

  • 01:57: That acceleration matches the effect you would get if empty space itself had a tiny bit of energy.
  • 03:02: For obscure reasons that we delve into those episodes, negative pressure produces an anti-gravitational effect.
  • 03:10: ... dark energy has competing effects – its positive energy density gives it a positive gravitational effect ...
  • 03:50: Jamie Farnes was looking for a way to get an anti-gravitational effect that explained both dark energy AND dark matter.
  • 04:06: Forgetting that pressure stuff for a moment, positive masses and energies always have a positive gravitational effect.
  • 08:18: ... fluid – as a negative cosmological constant – has the same competing effects as regular dark energy, but in the opposite ...
  • 08:35: The direct effect is repulsive – antigravitational – which I guess was the original motivation for using negative matter.
  • 08:42: But that effect is overwhelmed by the effect of the pressure, which in this case is attractive – it works to recollapse the universe.

2018-12-06: Did Life on Earth Come from Space?

  • 00:37: ... I quote when the media says Harvard scientist says X this is received effectively as a pronouncement of truth from scientists when it is inevitably proven ...

2018-11-21: 'Oumuamua Is Not Aliens

  • 14:35: ... through matter, interactions with the electromagnetic field change the effect of mass of the neutrino by a process analogous to the refractive index, ...
  • 14:54: This is the Mikheyev-Smirnov-Wolfenstein or MSW effect.

2018-11-14: Supersymmetric Particle Found?

  • 13:47: Eddie Galtech asks why you can't get meaningful energy from the Casimir effect.
  • 14:03: Same with the Casimir effect.

2018-11-07: Why String Theory is Right

  • 03:47: When the graviton acts on another particle, it exerts its effect at an intersection in their world lines over some distance.
  • 04:06: More technically, you start to get runaway self-interactions, infinite feedback effects between the graviton and its own field.
  • 15:02: ... the Casimir effect is sometimes explained as resulting from the exclusion of virtual ...
  • 15:14: ... if the Casimir effect really is due to a change in the zero-point energy-- and there are those ...
  • 15:47: ... in the Casimir effect, the double horizon between the plates restricts what real particles can ...

2018-10-31: Are Virtual Particles A New Layer of Reality?

  • 03:43: Then you add the effects of doing this transfer in two, three, four packets, as well as every other idealized field interaction that you can imagine.
  • 06:23: ... calculate the effect of this, you add together the possible effect of every possible virtual ...
  • 11:44: A similar perturbation of the quantum vacuum is also seen in the Casimir and Unruh effects.
  • 11:50: ... for virtual particles to have an independent existence to explain these effects. ...

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

  • 02:48: We can't see this effect on earth-like planets yet, but the James Webb Space Telescope to launch in a year or so will get close to doing so.

2018-10-10: Computing a Universe Simulation

  • 12:49: ... of gas along that vast distance slowed down the light a little bit, effectively increasing the index of refraction of space, in the same way that light ...

2018-10-03: How to Detect Extra Dimensions

  • 13:45: So when you use perturbation theory to calculate an interaction in field theories, feedback effects give infinite loops of interactions.

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

  • 01:53: This results in the effect we perceive as gravity.
  • 04:38: ... that approach completely fails when you have strong gravitational effects on the smaller scales of space and time, like the central singularity of ...
  • 09:03: If not, you could build perpetual motion machines, for example, using the Casimir effect.
  • 10:46: When you have strong gravitational effects on the quantum scale, the self-energy corrections blow up to infinity.

2018-09-05: The Black Hole Entropy Enigma

  • 00:53: Also, we've seen them in their gravitational effects on their surrounding space and in the gravitational waves caused when they merge.

2018-08-15: Quantum Theory's Most Incredible Prediction

  • 04:42: The fine structure constant is named after this effect.
  • 07:06: It's really incredible that we can even begin to calculate the effect of the messy buzzing electromagnetic field.
  • 07:13: But in fact, we can calculate its effect extremely precisely and test this through experiments, showing the underlying truth of quantum theory.
  • 10:04: The more complicated the interaction, the less it contributes to the overall effect.
  • 15:51: ... days to cross the distance between Earth and the sun, and making its effect even more powerful than if it had happened ...

2018-06-27: How Asteroid Mining Will Save Earth

  • 00:59: ... but there's another natural resource that's never been touched, is effectively inexhaustible, and has a dollar value large enough to disrupt entire ...
  • 06:04: ... materials like iron, nickel, aluminium, and titanium are not cost effective to bring back to Earth, but they can go towards building infrastructure ...

2018-06-20: The Black Hole Information Paradox

  • 08:44: He did a more careful calculation of the effect of infalling material and found that it doesn't exactly freeze above a completely static horizon.

2018-05-16: Noether's Theorem and The Symmetries of Reality

  • 11:05: ... will find more small solar system objects, detect the effects of weak gravitational lensing in distant galaxies, and see more distant ...

2018-04-25: Black Hole Swarms

  • 04:49: Black holes are effectively invisible, but things can be different if a black hole and a companion star are in a binary orbit around each other.
  • 10:44: This is either constructively producing a stronger stretching or contraction of space or destructively, meaning their effect cancels out.

2018-04-18: Using Stars to See Gravitational Waves

  • 06:50: Gravitational radiation should have physical effects as shown by the sticky bead argument first presented by Richard Feynman.
  • 07:52: ... it may be possible to observe this effect in the dense star fields of galactic cores if those galaxies also ...
  • 08:03: A similar effect may cause white dwarf stars in binary orbits to explode as they absorb gravitational radiation from their own orbits.

2018-04-11: The Physics of Life (ft. It's Okay to be Smart & PBS Eons!)

  • 10:57: Last week, we talked about the mysterious Unruh effect, in which accelerating observers find themselves bathed in a sea of particles.
  • 12:18: Ultimately, that's the source of energy for whatever effects those Unruh particles cause, whether or not you actually see the Unruh particles.
  • 13:22: ... the Schwarzschild radius of a kugelblitz might create the Zitterbewegung effect. ...

2018-04-04: The Unruh Effect

  • 00:23: ... Stephen Fulling, Paul Davies, and William Unruh-- were looking at an effect that now seems eerily ...
  • 01:09: This is the Fulling-Davies-Unruh effect, or sometimes just the Unruh effect.
  • 06:41: This is the Unruh effect.
  • 06:43: Now, there's a big difference between the Unruh and Hawking effects.

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

  • 04:40: Then they averaged the observed motion of all of those stars and removed the effects due to the rotation of Andromeda and the motion of the sun.
  • 10:06: ... it's the name we give to the effect, whereby the gravitational response of the universe doesn't match the ...

2018-03-15: Hawking Radiation

  • 04:33: But what would the effect be?
  • 06:06: But to understand the effect of the close encounter with the black hole, he required an uneasy marriage of quantum mechanics and general relativity.
  • 06:23: These can be used to approximate the effect of curved spacetime on quantum fields by smoothly connecting regions of flat space.

2018-02-28: The Trebuchet Challenge

  • 00:59: In fact, we're going to calculate the very tangible effects of this intangible, abstract stuff.
  • 05:38: But in a real energy calculation, losses due to non-conservative effects like friction and air resistance can be accounted for.

2018-02-14: What is Energy?

  • 05:37: It may encounter energy sapping effects, like friction or air resistance, so-called dissipative or non-conservative forces.
  • 10:48: This leads to effects like dark energy and the accelerating expansion of the universe.

2018-01-31: Kronos: Devourer Of Worlds

  • 07:19: We talk a bit about the effects of Jupiter on our own solar system in this episode.

2018-01-24: The End of the Habitable Zone

  • 02:54: Now that's way too small to have any effect on human time scales.
  • 03:45: CO2 warms the surface due to its greenhouse effect and warm oceans are less able to absorb carbon so more CO2 is released.
  • 05:56: ... the early Earth had a much stronger greenhouse effect due to high carbon dioxide or methane content, then the increased heat ...
  • 07:05: For example, the increase in the greenhouse effect due to increased atmospheric water vapor will speed things up.

2018-01-17: Horizon Radiation

  • 01:53: ... coming episodes, we will be delving into Hawking radiation and the Unruh effect, both of which are very similar and are results of this observer ...
  • 02:14: So we're going to take this episode to lay the final stepping stone we need to examine these effects in detail and accurately.
  • 11:31: In some cases, changing the boundaries of space time actually reduces the number of particles, for example, in the Casimir effect.
  • 11:39: Now we've already seen how this effect reduces the energy of the vacuum between conducting plates.
  • 12:56: Extremely large quakes can set the entire star ringing, which is observable in its effect on the extremely regular flashes of its pulsar jet.

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

  • 01:46: And although we can't hear this resonant vibration directly, we can see its effect in the changing brightness and the motion of the stellar surface.
  • 02:16: The effects of seismic activity can be mapped across its surface.
  • 04:57: And because many different modes overlap, the complex overlapping effects of these oscillations are separated using Fourier analysis.
  • 06:51: They're too far away to resolve their surfaces, so we only see the global effects of their oscillations.
  • 12:14: They'd protect us against the fallout effects of increased UV.
  • 13:17: ... an effect called relativistic beaming massively amplifies our perceived brightness ...

2017-12-20: Extinction by Gamma-Ray Burst

  • 00:35: ... the most imminent, like asteroid strikes, or at least deal with their effects, like the damage caused by gamma-ray bursts and ...
  • 04:00: Instead, the danger is in the long-term effects on the atmosphere.
  • 08:46: However, for a supernova to produce the same effects, it needs to be much closer, within 20 to 30 light years.
  • 11:50: The global effects, however, would be limited.

2017-12-06: Understanding the Uncertainty Principle with Quantum Fourier Series

  • 02:06: The uncertainty principle exists alongside this observer effect.

2017-11-29: Citizen Science + Zero-Point Challenge Answer

  • 06:10: Now, geckos cling to surfaces by using what is essentially the Casimir effect between the tiny hairs, setae, on their feet and the surface.
  • 06:28: ... average gecko might be able to effectively apply 200,000 of their millions of setae at any one time, and each seta ...

2017-11-08: Zero-Point Energy Demystified

  • 04:18: In fact, there is one way to do this-- with the Casimir Effect.
  • 05:18: Well, if we define the average vacuum energy as 0, then the Casimir Effect produces negative energy.
  • 05:32: The gravitational effect of energy depends on its absolute value.
  • 07:47: ... hairs are close enough to the surface so that Casimir forces come into effect. ...

2017-11-02: The Vacuum Catastrophe

  • 05:07: Vacuum energy should produce a gravitational effect, and a huge vacuum energy should produce a huge gravitational effect.
  • 05:15: That effect would be seen in two ways.
  • 07:20: ... unlike the Lamb shift or the Casimir effect, the observation of accelerating expansion allows us to measure the ...

2017-10-25: The Missing Mass Mystery

  • 07:30: See, the vast tidal effects of nearby galaxies create shocks that can heat those baryons to hundreds of thousands or even millions of Kelvin.
  • 08:14: The secret is the thermal Sunyaev-Zel'Dovich effect.
  • 08:20: We talked about the kinetic SZ effect in our episode on dark flow.
  • 09:00: ... the results of their attempts to look for the Sunyaev-Zel'Dovich Effect. ...
  • 09:29: The SZ effect is tiny.
  • 09:44: Both teams report detection of the thermal Sunyaev-Zel'Dovich effect with around 5 sigma significance.
  • 11:21: A non-zero vacuum energy would have a gravitational effect.

2017-10-19: The Nature of Nothing

  • 08:15: Another way to hunt for virtual particles is through their bulk effect on the vacuum.
  • 09:21: ... Casimir effect was only successfully measured in 1996 by Steven Lamoreaux at the ...
  • 09:51: Neither the Casimir effect nor the Lamb shift allow measurement of the absolute strength of vacuum energy.
  • 09:57: They just measure its relative effect, inside versus outside Casimir plates, or between electrons in neighboring orbits.

2017-10-04: When Quasars Collide STJC

  • 04:21: ... US Virgin Islands and through the continental United States to give an effective antenna size of over 8,000 ...

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

  • 04:18: ... first measurement of this fundamental parameter was through its effect on the fine grain structure of atomic energy levels, which is where the ...
  • 04:28: This effect is also how we'll test whether Alpha is changing.
  • 04:48: We see this effect in the sharp spikes or dips in light at specific wavelengths when we observe the spectrum of a gas.
  • 05:38: ... spin and by its orbital motion actually interact with each other in an effect called spin orbit ...

2017-09-20: The Future of Space Telescopes

  • 03:04: The effect of diffraction would be easier to isolate than for a typical internal coronagraph.
  • 09:01: ... that commercial lasers could corral and shape the particles into an effective mirror or ...

2017-09-13: Neutron Stars Collide in New LIGO Signal?

  • 14:10: That method is to watch the effect on the parent stars' light as it passes through the planet's atmosphere.

2017-08-30: White Holes

  • 09:46: ... it's conceivable that an incredibly rare entropy dip could lead to an effective reversal of time and a white hole could ...

2017-08-24: First Detection of Life

  • 01:35: ... and so probably the first-- way we'll spot alien life is by its effect on its planet's atmosphere-- in particular, the chemical content of that ...

2017-08-16: Extraterrestrial Superstorms

  • 02:26: So as air rushes in all directions into a low-pressure storm cell, the Coriolis effect causes it to curl around in a circle.

2017-08-10: The One-Electron Universe

  • 04:43: ... frame, its direction of motion appears reversed, which has the same effect as flipping its ...

2017-08-02: Dark Flow

  • 03:27: To explain this, I'll need to tell you about the kinematic Sunyaev-Zeldovich, KSZ, effect.
  • 03:33: And actually, let's just start with the regular old thermal Sunyaev-Zeldovich effect.
  • 04:17: Now, kinematic Sunyaev-Zeldovich effect is much, much harder to see than the thermal SZ effect.
  • 04:24: ... some extra peculiar velocity in addition to the Hubble flow, then the SZ effect adds an extra Doppler shift to the CMB photons that pass through that ...
  • 04:54: ... effect is really, really tiny, and it can only tell us the component of the ...
  • 05:07: But what if you could measure the effect from hundreds of clusters across the observable universe?

2017-07-26: The Secrets of Feynman Diagrams

  • 13:38: As space junk builds up, a runaway effect is possible in which more and more satellites are destroyed, exponentially increasing the amount of debris.
  • 14:02: But that could increase dramatically if this domino effect begins.

2017-07-19: The Real Star Wars

  • 03:04: This was really the only effective way to monitor the rapid proliferation of launch facilities.
  • 10:02: The program was even upgraded in the late '70s to be effective against the upcoming US Space Shuttle.

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

  • 04:19: And from that equation, it's possible to perfectly calculate the effect of that simple exchange.
  • 04:31: For that reason, this simple calculation gives the wrong repulsive effect between two electrons.
  • 08:45: This impedes the electron's motion and actually increases its effective mass.
  • 08:50: The effect is called self-energy.

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

  • 06:35: If true, that would lead to some weird effects.

2017-06-07: Supervoids vs Colliding Universes!

  • 03:41: Inoue and Silk in 2006 first proposed the cold spot could be the imprint of a supervoid via the so-called Integrated Sachs-Worlfe, or ISW, effect.
  • 03:54: The ISW effect is dark energy in action.
  • 04:53: The ISW effect would be tiny, in fact negligible, in a universe without dark energy.
  • 06:21: ... the combined ISW effect they calculated from all four voids should only have produced 32 ...
  • 06:53: G23's ISW effect is calculated to yield a 14 microkelvin drop in the CMB.
  • 07:07: So the control sample shows that calculating ISW effect can lead to a number that matches the true effect.
  • 07:51: ... the idea is that the calculation of the ISW effect, the effect of the voids, is lower than expected because we don't ...

2017-05-31: The Fate of the First Stars

  • 06:15: It turns out that even a sprinkling of heavier elements produces a powerful cooling effect.
  • 12:14: It doesn't even have to be a huge effect.

2017-05-17: Martian Evolution

  • 02:15: It's an emergent effect of mutation and natural selection.
  • 03:19: This could have different effects.
  • 03:33: But there's another effect to consider.
  • 07:04: It depends which of these effects we better handle with technology.
  • 08:36: And this effect may actually speed up their divergence from the humans of Earth.
  • 09:12: This effect will be amplified on Mars because the intermixing with Earth populations will be minimal.

2017-05-10: The Great American Eclipse

  • 05:31: They may be an atmospheric effect, perhaps from the same turbulence that makes stars twinkle.
  • 10:09: A few people brought up the Mandela effect as evidence that we live in a simulation.
  • 10:14: ... those who haven't encountered it, the Mandela effect is when many people share the same specific misremembering of something, ...

2017-04-05: Telescopes on the Moon

  • 11:33: ... hole at the singularity is expected to produce an antigravitational effect through negative pressure, in a way that's mathematically similar to ...

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

  • 00:55: ... that we call the spacetime interval governs the flow of cause and effect, the only reliable ordering of events in a relative ...

2017-03-15: Time Crystals!

  • 04:25: This is the same effect that results in magnetic materials.
  • 06:08: ... messy and the interaction strength is too weak, then the time crystal effectively melts into regular time symmetric matter, in which the ion chain follows ...
  • 06:39: At that point, thermal effects take over and the rhythm dies.

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

  • 02:59: ... zone for a given star based on the intensity of its photon flux and the effect of atmospheric greenhouse ...
  • 03:29: ... planets may be more Venusian, so overheated due to a runaway greenhouse effect. ...
  • 10:33: However, Galileo did make massive improvements in the design and effectively invented the use of telescopes for astronomy.

2017-02-15: Telescopes of Tomorrow

  • 05:02: Together, they provide an effective aperture, 24.5 meters in diameter, and a collecting area over 80 times Hubble's and nearly 15 times Webb's.
  • 09:06: ... as their brightnesses fluctuate due to the changing gravitational effect of nearby massive ...
  • 11:10: So last time, I showed you how you can visualize the effects of special relativity on spacetime using geometry.

2017-02-02: The Geometry of Causality

  • 00:15: ... into Einstein's theory to find that the immutable ordering of cause and effect emerges when we discover the causal geography of ...
  • 13:24: We actually do see the effect of time dilation in some of the x-ray light coming from right near the black hole.

2017-01-25: Why Quasars are so Awesome

  • 05:48: Oh, and if one of these jets happens to be pointed directly at us, then we see strange effects due to the near light speed motion of the jet material.
  • 05:57: In an effect called relativistic beaming, the light from the jet is vastly magnified.

2017-01-11: The EM Drive: Fact or Fantasy?

  • 06:05: The big one seems to be that thermal effects could still be a factor, in particular, deformation of the device or the scale due to thermal expansion.
  • 08:42: All of that said, if the observed effect really is a thrust, then something is causing it.
  • 10:05: Harlan Kempf asks whether a radio interferometer could be built across multiple planets and what would be the effect on resolution.

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

  • 00:40: Although they don't emit any light themselves, they can have a very visible effect on their surroundings.
  • 00:46: The most spectacular effect is when black holes feed.
  • 03:14: The effect is a telescope thousands of kilometers in diameter, at least in terms of its spatial resolution.
  • 04:09: At visible wavelengths, this should look like a brightening of the star, an effect called microlensing.

2016-12-21: Have They Seen Us?

  • 07:07: When connected up, it'll effectively form a giant radio telescope, with over a square kilometer surface area.

2016-12-14: Escape The Kugelblitz Challenge

  • 03:27: On the Penrose diagram, we should extend our effective event horizon backwards to include that space.
  • 04:42: Now, light has energy and so has a gravitational effect.

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

  • 09:18: Not only does the entire wave function know the properties of the particle, but the entire wave function can be effected instantaneously.

2016-11-09: Did Dark Energy Just Disappear?

  • 00:52: They expected to see that this expansion rate was slowing down due to the gravitational effect of all of the matter in the universe.
  • 04:14: ... equations of general relativity to give the anti-gravitational effect of dark ...
  • 06:35: ... there are things that slow expansion, which is just the gravitational effect of regular energy, and that's mostly dark matter, but also stars, ...
  • 11:03: ... us that there has to be something out there countering the gravitational effect of matter and flattening the geometry of ...
  • 12:01: There were differences between the experiments, so what effect did these differences have?
  • 12:07: ... taking a long and careful look at the evidence for dark energy, and its effect on the expansion of ...

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

  • 00:44: However, at extremely cold temperatures, this thermal motion is so small that quantum effects can dominate the behavior of certain materials.
  • 02:11: ... quantized magnetic field observed in the mysterious "quantum hole effect." These findings will lead to some spectacular applications in the future, ...

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

  • 10:19: Any given timeline is a predictable chain of cause and effect.

2016-10-12: Black Holes from the Dawn of Time

  • 05:21: Depending on PBH mass, this would cause a twinkling effect-- microlensing.
  • 05:44: As the heavier ones buzz around the galaxy, they should pull apart loosely bound binary systems and have an effect on the structure of star clusters.

2016-09-29: Life on Europa?

  • 11:37: ... way of saying that is that this measurement interaction effectively entangles the measured particle and its partner with a macroscopic ...

2016-09-21: Quantum Entanglement and the Great Bohr-Einstein Debate

  • 03:05: This is fundamental to Einstein's relativity, which tells us that the chain of cause and effect can't propagate any faster than the speed of light.
  • 05:15: In the case of quantum spin, that measurement effect is especially weird.

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

  • 06:27: That said, smaller rocks can still have a devastating, albeit not-species-threatening, effect.

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

  • 02:13: ... called "photons." Einstein demonstrated this through the photoelectric effect but his clue came from the quantized energy levels of Max Planck's ...
  • 04:56: This crazy effect has even been observed with whole atoms, even whole molecules.

2016-07-06: Juno to Reveal Jupiter's Violent Past

  • 00:50: In fact, its effect during the first billion years of the solar system's formation defines the positions of all planetary orbits.

2016-06-22: Planck's Constant and The Origin of Quantum Mechanics

  • 00:23: In fact, you can see the effect of this quantum behavior and even measure the Planck constant just by observing the color of sunlight.
  • 10:09: Einstein proved this through the photoelectric effect.

2016-06-15: The Strange Universe of Gravitational Lensing

  • 00:06: Much of the deep universe is shifted and magnified by the warping effect of gravitational lensing.
  • 03:03: For stars, this effect is typically small.
  • 06:43: Although this sort of obvious strong lensing is rare, the effects of gravitational lensing are everywhere.
  • 07:16: Even within the Milky Way, we see the effect of lensing.
  • 11:19: ... was one of the early interpretations of some of the weird quantum effects developed in the ...
  • 12:13: But from the standpoint of us, the observer, the effect is the same.

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

  • 07:02: However, the full effect takes longer, because it depends on positive feedback cycles.
  • 07:40: ... gently asks whether we really can be certain of the broad extent of an effect, given that we can't perfectly accurately model every ...
  • 08:19: ... shifting climate zones, reduced ice coverage, et cetera, whose current effects are very ...
  • 11:44: Add these two numbers together, and you get that matter and dark energy both produce a significant effect for around two doublings.

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

  • 07:32: Tune the path lengths until the weird effects of entanglement emerge, and you know that they are equal.

2016-05-25: Is an Ice Age Coming?

  • 03:29: So this shouldn't be a huge effect.
  • 03:47: Together, these two effects define where in the orbit the seasons occur.
  • 06:37: This is totally weird, because eccentricity should produce a much smaller effect than obliquity.
  • 08:28: Cooler oceans are better at absorbing carbon dioxide from the atmosphere, and so the Earth's natural greenhouse effect is diminished.
  • 13:17: Now, Physics Girl has an excellent video describing this effect.

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

  • 00:07: It's strange anti-gravity effect is unlike anything we've ever encountered.
  • 03:06: It's anti-gravitational effect emerges in the second Friedmann equation.
  • 05:17: Instead, the overall effect of pressure on the curvature of space time is a purely relativistic effect.
  • 05:39: ... ultimate effect is that the massive of a region of the universe is higher if its ...
  • 07:03: And that means its anti-gravity effect must come from its physical properties.
  • 07:08: The effect of the cosmological constant is the combined effect of dark energy's own density and pressure.
  • 08:20: That's where dark energy's crazy anti-gravity effect comes from.
  • 09:01: Again, this is due to its relativistic effect.
  • 09:05: The direct effect of dark energy's negative pressure doesn't do anything, because that negative pressure is the same everywhere in the universe.
  • 09:14: But even though the negative pressure has no direct effect, it has its relativistic effect.
  • 09:29: The relativistic effective of negative pressure is actually really, really hard to describe intuitively.
  • 10:35: That looks like negative pressure, and yet this abstract-sounding negative pressure has a very real physical effect.
  • 10:44: It's the opposite effect to positive pressure.
  • 10:47: And it's a clear, outward-pushing anti-gravity effect when we look at its role in the second Friedmann equation.

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

  • 04:06: Dark energy has dominated the universe only during the tenure of life on Earth, although its effect has been felt for a bit longer than that.
  • 05:11: It's only right now that both have a measurable effect.
  • 05:17: For how many of those past 100 doublings has dark energy had any significant effect-- let's say at least 10% of the energy density?
  • 05:29: ... future doublings will regular matter and energy have any significant effect-- again, at least 10% of the energy ...
  • 05:43: ... me how many billion years ago dark energy started to have a significant effect and how many billion years in the future will it take for matter to ...

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

  • 09:01: Dark energy does drive the expansion rate, causing a sort of anti-gravity effect.
  • 09:06: But if dark energy diluted away, like regular matter does, that effect would diminish as the universe expanded.
  • 10:33: Sandeep Siwach would like to know why dark energy only effects the space between galaxies and not within galaxies.
  • 10:40: So dark energy only has an observable effect when its density is at least comparable to the density of regular matter.

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

  • 00:52: ... universe and the resistance to this expansion due to the gravitational effect of everything it ...
  • 08:46: ... which will give us the insight we need to understand dark energy's effect on the future of ...
  • 10:28: ... does include dark matter, which we can measure by its gravitational effect in several independent ...

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

  • 05:40: But that oomph is resisted by the gravitational effect of all the master and energy in the universe.

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

  • 07:23: Incidentally, it also describes the effect of dark energy, and that may not be a coincidence.

2016-03-16: Why is the Earth Round and the Milky Way Flat?

  • 02:53: And this type of dimensional egalitarianism is also shared by another effect, ultimately leading to the ball shapes of stars, planets, and moons.
  • 03:05: Before we talk about what that other effect is, let's talk about planets.
  • 06:00: And unless there are other effects in place to resist these forces, then everything has to move until it finds an equilibrium.
  • 08:36: It's because the effect that prevents their collapse has a very different symmetry.
  • 09:58: Spheres happen when pressure is the dominant effect resisting gravity.
  • 10:10: That's a circularly symmetric effect, and so you get, well, a circle.

2016-03-09: Cosmic Microwave Background Challenge

  • 02:53: That plasma was effectively opaque because photons couldn't travel far without bouncing off all those free electrons.

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

  • 03:34: Because of the relativistic Doppler effect.
  • 03:37: The relativistic Doppler effect classically changes the wavelengths of light, blue-shifting approaching material and red-shifting receding material.
  • 05:48: One effect, time dilation, slows down the tick rate of the approaching clock.
  • 05:53: At the same time, the relativistic Doppler effect speeds it up.
  • 05:57: So which effect wins?
  • 06:08: The relativistic Doppler effect will speed up an approaching clock by 1 over 1 minus v on c.
  • 06:46: ... you think of just the time dilation, and not the Doppler effect, you get that the moving clock is always around 13% percent slower than ...
  • 06:56: By the way, this is an effect that we see out there in the universe all the time.
  • 07:12: ... of the universe appear to die away far more slowly due to the combined effect of time dilation and the Doppler ...

2016-02-03: Will Mars or Venus Kill You First?

  • 03:19: The effect is called ebulism.

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

  • 08:37: This gives us an ordered sequence of cause and effect-- this, then that.
  • 11:16: And special relativity only describes the relative effects on time and space due to a constant relative motion.
  • 11:23: To account for the effect of acceleration, you need to use general relativity.

2016-01-20: The Photon Clock Challenge

  • 00:42: It's a very real effect.

2016-01-13: When Time Breaks Down

  • 04:28: This effect is the time dilation of Einstein's special relativity.
  • 08:55: Shouldn't the resistance to acceleration produced by a compressed spring only take effect along the length of the spring, as opposed to the side?

2016-01-06: The True Nature of Matter and Mass

  • 01:22: Let's ignore the gravitational effect of mass for the moment, and just consider mass as the degree to which an object resists being accelerated.
  • 03:45: Again, we can describe this in terms of a straightforward physical effect.
  • 04:16: ... seemingly very different physical effects-- the box of photons and the compressed spring-- both give the same ...
  • 07:23: The presence in the flow of energy and momentum as well as pressure all have their quite different effects on the curvature of space-time.

2015-12-16: The Higgs Mechanism Explained

  • 07:55: ... horizon, the light it emits is red shifted such long wavelengths that it effectively becomes ...
  • 08:06: ... sees does grow because anything falling into the black hole adds to its effective mass as seen by a distant observer even before it crosses the event ...

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

  • 00:21: ... relativistic entities, as space time regions whose boundary curvature effectively removes the interior from our observable ...
  • 07:31: This is a quantum effect, even though it's happening on the scale of a star.

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

  • 06:08: The angle of the thrusters ends up being around 30 degrees, so the effective exhaust velocity is the backwards or reverse component of the thrust.

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

  • 02:12: At two to three kilometers, the sky goes dark from the ejector, and nuclear winter effects global climates.

2015-10-28: Is The Alcubierre Warp Drive Possible?

  • 03:44: We can create something like it, a negative pressure, on quantum scales via Casimir effect.
  • 05:33: ... and you hypothetically soften the fabric of space via higher dimensional effects-- literally, a hyper space warp ...
  • 06:02: Quantum scale manipulation of the vacuum energy a la the Casimir effect may be enough.

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

  • 07:15: The longer the effective range of the beam, the higher the speed we can reach.

2015-10-07: The Speed of Light is NOT About Light

  • 03:39: We measure its effect.
  • 10:02: There is no time and space, no cause or effect, because all locations and times communicate with each other instantly.

2015-09-30: What Happens At The Edge Of The Universe?

  • 08:09: And that mass predicts the deflection angle for light passing the Sun perfectly, that is its gravitational lensing effect.

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

  • 04:35: But they ultimately have a hard time getting all of the observed effects.
  • 08:48: The monkey may see some time dilation effects from the local part of its universe.

2015-08-27: Watch THIS! (New Host + Challenge Winners)

  • 04:07: And the effective potential formulation for radio [INAUDIBLE].

2015-08-19: Do Events Inside Black Holes Happen?

  • 09:00: By the way, bigger black holes also have smaller tidal effects near their horizons.
  • 13:33: ... are gravitational effects from the Sun and Moon that do the same thing, but they're highly, highly ...

2015-08-05: What Physics Teachers Get Wrong About Tides!

  • 00:42: ... net effect of this differential of the Moon's gravity across the Earth is to ...
  • 02:16: The Sun's effects are going to work analogously, anyway.
  • 07:25: First, the Sun-- its effects on tides are analogous to those of the Moon, but they're only about a third as big.
  • 07:33: Now, when Earth, the Moon, and the Sun all line up in space, the effects are additive and you get extra-large spring tides.

2015-07-29: General Relativity & Curved Spacetime Explained!

  • 05:49: ... making any assumptions about how gravity effects light, that would be true even if it turned out that gravity slowed ...
  • 06:36: ... can speak about space and time separately at all, most of the everyday effects on earth that Newton would attribute to gravity are due to curvature in ...

2015-07-08: The Leap Second Explained

  • 01:47: Of course, Earth's rotation has irregularities due to earthquakes and other effects.

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

  • 01:57: We'll end up seeing that all the supposedly gravitational effects on motion can be accounted for just by the geometry of spacetime.
  • 09:18: ... magnetic pole reversal wouldn't affect Earth's orbit or the tilt, any effects on the seasons would be ...
  • 09:25: Indigo said that tracking time in the future might become a challenge if you have to consider relativistic effects.

2015-06-24: The Calendar, Australia & White Christmas

  • 00:53: See, Earth bulges slightly at the equator due to centrifugal effects from its own spin.
  • 04:33: Now, one effect of all this orbital craziness is that the mean tropical year is actually getting shorter by about a half second every 100 years.
  • 04:49: ... all of these effects would put the equinoxes ahead of the calendar by eight to nine days ...

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

  • 00:00: [SOUND EFFECTS PLAYING] [MUSIC PLAYING] Hey, Space Timers.

2015-06-03: Is Gravity An Illusion?

  • 05:39: ... if the so-called "real" downward gravity from Earth is also fake, a side effect generated because Earth's surface is really accelerating ...
  • 12:02: BJ Klophaus does the film and sound editing and sound effects and Michael Leng does the animation and graphics.

2015-05-27: Habitable Exoplanets Debunked!

  • 10:17: ... that happened, then effectively the kilogram would be redefined as the total amount of effective mass ...

2015-05-13: 9 NASA Technologies Shaping YOUR Future

  • 08:46: ... might be long term negative effects to which women are more susceptible that we haven't even seen yet, and a ...

2015-05-06: Should the First Mars Mission Be All Women?

  • 04:14: ... attention in late 2014 when writer Kate Greene wrote an article to this effect in "Slate." Greene was one of six volunteers-- three men and three ...
  • 07:56: I agree it has slow RPMs and low Coriolis effects, but it only has 0.7 earth Gs, which might be intentional.
  • 08:10: And Watchit1337 supplied numbers for the "Gundam" ships, which if right, I agree would produce minimal Coriolis effects.
  • 08:25: ... is done apparently in "Mass Effect," the "Expanse" series, another Niven work called "The Mote in God's Eye." ...
  • 08:52: ... Conte asked why we didn't bring up gravity gradient effects, namely that in a small ring-- this is not as a big a problem in large ...
  • 09:02: I didn't bring this up because we don't entirely know the effects of that.
  • 09:11: But in the short term, the Coriolis effects are a lot more significant.
  • 09:22: ... and gravity here but no net angular momentum, and thus no net gyroscope effects. ...
  • 09:33: ... at a pretty fast clip but doesn't seem to have any weird Coriolis effects. ...
  • 09:43: The reason is that if he's driving along the axis of the space station, there would be no Coriolis effects.
  • 09:47: The Coriolis effects would only be there if you move along the rim, not along the axis.

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

  • 02:27: It turns out that there's a simple formula for how big the effective surface gravity produced by this rotating structure would be.
  • 03:17: ... produce 1 Earth g of effective gravity at its surface or 10 meters per second squared, our earlier ...
  • 03:31: Unfortunately, in real life, even a few RPMs in such a small craft would create a lot of weird effects that "2001" overlooks.
  • 03:56: That apparent departure from straight line motion in rotating reference frames is called the Coriolis effect.
  • 04:09: At 10.5 RPMs, the effect is big enough that Poole's arms would flail as he punched.
  • 04:27: ... what we see in "2001." But there are other more subtle physiological effects whose effects we should ...
  • 04:40: On the rotating ship, standing up would therefore make your head want to curve forward from the Coriolis effect, knocking you over.
  • 04:57: ... small radius and high rotation rate, it ends up sweeping major Coriolis effect under the rug, especially the part where Poole would be constantly ...
  • 05:31: ... velocity would be small enough that, just like on Earth, Coriolis effects would only be noticeable at very high ...
  • 05:45: There would be no Coriolis effects sideways.
  • 06:10: So bigger is better for reducing the Coriolis effect.
  • 06:34: The Coriolis effect at such RPMs would be undetectable in ordinary human activity.

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

  • 02:05: Now for nearby events, the effect is microscopic, but so what?

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

  • 05:00: The effects when you're releasing that little mass are basically additive.

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

  • 02:52: But if everything lines up just right, then over billions of years, they could have a sizable cumulative effect and distort those orbits.
  • 03:38: As in weather forecasting, you have a butterfly effect situation that's highly unpredictable.
  • 04:18: Well, it's not that simple because there's a competing effect.

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

  • 03:19: ... so much CO2 on Venus that the greenhouse effect makes the surface hotter than hell-- over 450 degrees Celsius, well ...

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.
  • 01:09: Now a planet's surface gravity has a huge effect on how high you can jump on that world.
224 result(s) shown.