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	2022-12-14: How Can Matter Be BOTH Liquid AND Gas? 01:29: The relationship between temperature, pressure, and phase is mapped on a phase diagram. 02:11: ... both temperature and pressure in the right proportions we follow the phase transition boundary between liquid and ... 02:55: And beyond it is an entirely new state of matter - the here-be-dragons of the phase diagram. 03:00: This is a land with no boundaries - a sort of no-man's land where liquids can skirt around the phase boundary and become gasses without ever boiling. 03:27: What does it even look like to transition between states without ever crossing a phase transition boundary? 05:48: We know what we need to know, to take a journey to that strange new land of the phase diagram. 05:54: Let’s see what it looks like for a liquid to pass into the supercritical phase. 06:36: ... sublimation causes pressure to rise, taking us into the realm of the phase diagram where liquid CO2 is ... 07:27: ... has no effect because liquids are incompressible, but look at the phase diagram: At higher pressures the boiling point of CO2 increases, which ... 08:01: But we’re approaching our strange new region of the phase diagram, where the rules are going to change Let's talk about density for a moment. 08:27: At that point, microscopic droplets of remaining liquid are free to flow and swirl through the gas phase to diffuse. 09:46: When ice is applied to the chamber, temperature drops and CO2 liquid rapidly condenses from the supercritical phase. 11:15: ... the water and then you can turn the CO2 back into a low-density gas phase, leaving the gel lattice intact and full of ... 03:00: This is a land with no boundaries - a sort of no-man's land where liquids can skirt around the phase boundary and become gasses without ever boiling. 01:29: The relationship between temperature, pressure, and phase is mapped on a phase diagram. 02:55: And beyond it is an entirely new state of matter - the here-be-dragons of the phase diagram. 05:48: We know what we need to know, to take a journey to that strange new land of the phase diagram. 06:36: ... sublimation causes pressure to rise, taking us into the realm of the phase diagram where liquid CO2 is ... 07:27: ... has no effect because liquids are incompressible, but look at the phase diagram: At higher pressures the boiling point of CO2 increases, which means all ... 08:01: But we’re approaching our strange new region of the phase diagram, where the rules are going to change Let's talk about density for a moment. 11:15: ... the water and then you can turn the CO2 back into a low-density gas phase, leaving the gel lattice intact and full of ... 02:11: ... both temperature and pressure in the right proportions we follow the phase transition boundary between liquid and ... 03:27: What does it even look like to transition between states without ever crossing a phase transition boundary? 02:11: ... both temperature and pressure in the right proportions we follow the phase transition boundary between liquid and ... 03:27: What does it even look like to transition between states without ever crossing a phase transition boundary?
	2022-11-23: How To See Black Holes By Catching Neutrinos 08:40: ... currently in a feeding phase - gas from the surrounding galaxy has been driven to the center, forming ... 10:29: ... neutrino detection and it was revealed to be in a particularly active phase, so there’s a good chance it was spitting out high energy neutrinos at an ... 08:40: ... currently in a feeding phase - gas from the surrounding galaxy has been driven to the center, forming a ...
	2022-10-19: The Equation That Explains (Nearly) Everything! 01:33: ... example, if we insist that the phase of the quantum wavefunction is fundamentally unmeasurable, then we need ... 02:21: ... to say exactly what is being distorted, as it is with the phase invariance of U(1). You may have noticed I skipped gravity. We’re still ... 09:45: ... is equivalent to the piece added to the Schrodinger equation to ensure phase invariance. And now we have to add the pieces for the other fields ... 02:21: ... to say exactly what is being distorted, as it is with the phase invariance of U(1). You may have noticed I skipped gravity. We’re still working on ... 09:45: ... is equivalent to the piece added to the Schrodinger equation to ensure phase invariance. And now we have to add the pieces for the other fields ...
	2022-10-12: The REAL Possibility of Mapping Alien Planets! 01:25: ... this requires exact measurement of the   arrival time and phase of the electromagnetic wave  - which gets harder the shorter the ... 07:45: ... and plenty more solar sails missions are in the design   phase. But getting to 550 astronomical units would be the most ambitious ... 14:06: ... involved is either existent,   or in the development phase. Nothing seems like a dealbreaker. There is no funded mission ...
	2022-09-21: Science of the James Webb Telescope Explained! 06:48: You celebrate for a few days, and get back to work on the next step - the phase 2 proposal. 06:57: The first step was the phase 1 proposal, by the way. 07:00: Phase 2 is when you lay out the exact observing plan in even more meticulous detail. 06:57: The first step was the phase 1 proposal, by the way. 06:48: You celebrate for a few days, and get back to work on the next step - the phase 2 proposal. 07:00: Phase 2 is when you lay out the exact observing plan in even more meticulous detail. 06:48: You celebrate for a few days, and get back to work on the next step - the phase 2 proposal.
	2022-08-03: What Happens Inside a Proton? 10:43: ... comes from adding up all the little   shifts in the particle phase from each step. Then at the end of the path, you add ... 11:28: ... path integral,   each time step results a complex-valued  phase shift at each spatial point. Those   complex numbers are fine ... 10:43: ... step. Then at the end of the path, you add together   the phases of all paths to get a probability. This is exactly like the famous ...
	2022-07-27: How Many States Of Matter Are There? 02:02: Change in temperature results in change in state, or in a phase. 02:06: ... Phase shifts occur at temperatures specific to the material, for example ice ... 02:38: Instead of a 1-dimensional relationship between phase and temperature, think of a 2-dimensional relationship with both temperature and pressure. 02:48: We call this a phase diagram. 03:12: The two numbers related on the phase diagram - temperature and pressure - are statistical properties of a large collection of particles. 07:09: To fully convince you that quark matter has its own states of matter, behold its phase diagram. 10:14: But if you increase the people-density to around 5 per square meter or more, a phase transition occurs. 10:50: Namely, lower the density when you see it’s approaching a phase transition. 02:48: We call this a phase diagram. 03:12: The two numbers related on the phase diagram - temperature and pressure - are statistical properties of a large collection of particles. 07:09: To fully convince you that quark matter has its own states of matter, behold its phase diagram. 03:12: The two numbers related on the phase diagram - temperature and pressure - are statistical properties of a large collection of particles. 02:06: ... Phase shifts occur at temperatures specific to the material, for example ice melts ... 10:14: But if you increase the people-density to around 5 per square meter or more, a phase transition occurs. 10:50: Namely, lower the density when you see it’s approaching a phase transition. 10:14: But if you increase the people-density to around 5 per square meter or more, a phase transition occurs.
	2022-06-30: Could We Decode Alien Physics? 16:39: ... material as reaction  mass and fusion fuel for the slowdown phase.   Actually Tony Tee   seems to have independently invented ...
	2022-06-22: Is Interstellar Travel Impossible? 16:52: ... but I think that we are asking one of the two questions: "what's your phase?" and "which detector did you go to?" Framed as yes/no ... 17:09: ... can either ask about the wave-like properties (for example the phase), or about the particle-like properties (which detector), but not both at ...
	2022-06-01: What If Physics IS NOT Describing Reality? 10:33: ... could tell you either which path the photon took,   or the phase of the photon by looking  at the interference pattern.   ...
	2022-04-27: How the Higgs Mechanism Give Things Mass 02:31: ... to a gauge field. We’ve seen an   example of this. The exact phase of the quantum  wavefunction from one point in space to ... 02:50: ... the Schrodinger equation that lets the  universe counteract these phase shifts.   That gauge field turns out to be  ... 03:09: ... that the laws of physics are invariant  under changes in local phase. The set   transformations that can change local phase ... 02:31: ... wavefunction from one point in space to the   next - local phase - doesn’t affect measurable  quantities - only relative phase ... 03:09: ... with just   “one” number in this case rotation of  phase angle vector of “unit” ... 02:31: ... local phase - doesn’t affect measurable  quantities - only relative phase matters. ... 02:50: ... the Schrodinger equation that lets the  universe counteract these phase shifts.   That gauge field turns out to be  electromagnetism, and ...
	2022-04-20: Does the Universe Create Itself? 06:24: ... was traveling both paths at the same time, then the combination of phase shifts in the beamsplitters causes the photons wavefunction to perfectly ...
	2022-03-08: Is the Proxima System Our Best Hope For Another Earth? 18:40: Two ways: if the loop shrinks itself down to zero size then the Higgs field phase angles can match up. 18:46: ... defect that I described in that episode - the simple vortex of phase angles making a loop around the string - is the most simplistic version ... 19:14: Brandon Munshaw asks if the Higgs phase angle something that could theoretically be measured? 19:20: Or are cosmic strings the only indication of a change in phase angle? 19:27: ... phase angle is fundamentally unmeasurable - just the the phase of the ... 19:37: ... the relative phase angle can in principle  be measured - that is, we  can see the ... 19:14: Brandon Munshaw asks if the Higgs phase angle something that could theoretically be measured? 19:20: Or are cosmic strings the only indication of a change in phase angle? 19:27: ... phase angle is fundamentally unmeasurable - just the the phase of the wavefunction - ... 19:37: ... the relative phase angle can in principle  be measured - that is, we  can see the ... 18:40: Two ways: if the loop shrinks itself down to zero size then the Higgs field phase angles can match up. 18:46: ... defect that I described in that episode - the simple vortex of phase angles making a loop around the string - is the most simplistic version of this ...
	2022-02-23: Are Cosmic Strings Cracks in the Universe? 00:58: ... to convince you that they probably do exist, we need to understand phase transitions   in quantum fields - we need to see how a ... 05:59: ... of the two components of the Higgs  field. We’ll call that the phase angle.   Across a single expanding region of ... 07:33: ... What do they look like and what do they do? Those  phase angles really do prefer to line up, which   means the loops ... 05:59: ... of the two components of the Higgs  field. We’ll call that the phase angle.   Across a single expanding region of decaying vacuum, the ... 07:33: ... What do they look like and what do they do? Those  phase angles really do prefer to line up, which   means the loops around ... 05:59: ... tried to rotate to line up. This led to textures of slowly shifting phase angles across   the universe. But if multiple bubbles join with  different phase ... 00:58: ... vapor   ionizes into plasma. But that’s not the final  phase transition. Keep heating until you hit   temperatures of the extremely ... 05:59: ... event. But   independent bubbles may have very different phase angles. When bubbles met, the Higgs phase angle at   the boundary ...
	2022-02-10: The Nature of Space and Time AMA 00:03: ... that we see in the distant past and it works um which is a put in phase all the axioms behind relativity including the constancy of the speed ...
	2021-12-20: What Happens If A Black Hole Hits Earth? 12:01: ... hole should quickly sear the rock around it into exotic high-pressure phases of quartz and pyrite that otherwise couldn’t be produced by regular ...
	2021-12-10: 2021 End of Year AMA! 00:02: ... still they're still gigantic um and these stars go through this these phases where the outer layers are fairly opaque okay so the outer layers ...
	2021-11-02: Is ACTION The Most Fundamental Property in Physics? 10:26: ... energy nor the proper time. Instead, it effectively calculates the phase shift that a particle picks up along each path towards a ... 11:00: ... it adds the phases of all conceivable paths to that destination. We find that the most ... 11:38: ... integral tells us that a particular final destination is likely if the phases of the many paths that could lead to that destination line up. Away from ... 12:16: ... proper time. In quantum mechanics configuration space could mean phase space - the space of possible positions and momenta - or it could be ... 11:38: ... points, very tiny changes in the path lead to rapid changes in the phase, causing those paths to cancel ... 10:26: ... energy nor the proper time. Instead, it effectively calculates the phase shift that a particle picks up along each path towards a ... 12:16: ... proper time. In quantum mechanics configuration space could mean phase space - the space of possible positions and momenta - or it could be more ... 11:00: ... it adds the phases of all conceivable paths to that destination. We find that the most ... 11:38: ... integral tells us that a particular final destination is likely if the phases of the many paths that could lead to that destination line up. Away from ...
	2021-10-05: Why Magnetic Monopoles SHOULD Exist 04:37: ... they predict are unaltered by changes in one simple property - the phase of the ... 06:52: In quantum mechanics, this works by shifting the phase of the particle’s wavefunction. 07:09: ... of the string, with its magnetic fields, should introduce different phase shifts depending on which side of the string the electron passes - and ... 07:29: The amount of the phase shift is proportional to the electric charge. 07:34: ... the right value of that charge, the phase shift induced between the different sides of the string is exactly one ... 07:29: The amount of the phase shift is proportional to the electric charge. 07:34: ... the right value of that charge, the phase shift induced between the different sides of the string is exactly one wave ... 07:09: ... of the string, with its magnetic fields, should introduce different phase shifts depending on which side of the string the electron passes - and that ...
	2021-09-21: How Electron Spin Makes Matter Possible 05:59: ... beam, a shift in one of them by half a wave cycle puts the two out of phase with each other. In that case they actually cancel each other out and ... 06:49: ... In that case a 360 degree rotation puts a spinor perfectly out of phase compared to its starting point. So a 360 rotation introduces a negative ... 07:22: ... returned to their initial state. But a 360 degree rotation shifts their phase by a half cycle and adds a -1 to the wavefunction. But we also know from ... 12:37: ... two electrons shoved into the same state end up perfectly out of phase and so destructively interfere. But you can’t just vanish electrons - so ... 06:49: ... In that case a 360 degree rotation puts a spinor perfectly out of phase compared to its starting point. So a 360 rotation introduces a negative sign to ... 05:59: ... out and you effectively have no photons. Mathematically, a half-cycle phase shift corresponds to putting a negative sign in front of the wavefunction. ...
	2021-09-15: Neutron Stars: The Most Extreme Objects in the Universe 09:34: ... and neutrons.   Nuclear physicists affectionately call this phase  of matter spaghetti. At slightly higher densities,   this ...
	2021-09-07: First Detection of Light from Behind a Black Hole 11:02: These three paths were apparent in the three distinct phases of the flare.
	2021-08-18: How Vacuum Decay Would Destroy The Universe 07:01: ... down into the true vacuum. This is vacuum decay. It’s a phase transition of the quantum fields.   In fact it has a lot of ...
	2021-07-13: Where Are The Worlds In Many Worlds? 08:14: ... no way to make a perfectly reliable measurement without corrupting the phase of the wavefunction in a way that destroys coherence - destroys the ... 08:28: ... still have two parts of the same electron’s wavefunction, but now the phase relationship, the correlation between peaks and troughs, is destroyed ... 09:04: Once there’s no longer a recoverable phase relation between the branches of the wavefunction, the worlds have separated forever. 09:21: But those parts of your brain wavefunction are out of phase with each other. 10:56: Is right-turning you sitting right there on the same train, but out of phase with left-turning you? 11:18: They overlap in location, but are so hopelessly out of phase that they can never interfere with each other - they just pass straight through. 11:26: ... that make up the other worlds fill all locations with all possible phases and so it's as though those ripples aren’t there at ... 11:36: A ripple pattern - a “world” - is only there if you share a phase relation with it. 12:07: Splitting happens when phase relations are scrambled due to interactions - and that’s - the entire universe doesn’t split with every atomic wiggle. 09:04: Once there’s no longer a recoverable phase relation between the branches of the wavefunction, the worlds have separated forever. 11:36: A ripple pattern - a “world” - is only there if you share a phase relation with it. 12:07: Splitting happens when phase relations are scrambled due to interactions - and that’s - the entire universe doesn’t split with every atomic wiggle. 08:28: ... still have two parts of the same electron’s wavefunction, but now the phase relationship, the correlation between peaks and troughs, is destroyed and so you ... 08:14: ... in a way that destroys coherence - destroys the relationship between phases of the wavefunctions emerging from both ... 11:26: ... that make up the other worlds fill all locations with all possible phases and so it's as though those ripples aren’t there at ...
	2021-07-07: Electrons DO NOT Spin 09:59: ... To get a little more technical - the spinor wavefunction has  a phase that changes with orientation angle - and a 360 rotation pulls it out ...
	2021-05-25: What If (Tiny) Black Holes Are Everywhere? 13:57: ... in a crystal to drop in energy to produce an identical photon matched in phase and direction of the ... 14:16: Those photons are entangled with each other because various properties are correlated - in particular phase, polarization, and momentum.
	2021-05-19: Breaking The Heisenberg Uncertainty Principle 06:05: This measurement is incredibly sensitive to the path lengths - but that means it’s also sensitive to the phase of the light waves. 06:11: Phase refers to the relative positions of the peaks and troughs of the waves. 06:16: Any variation in the relative phase of the two beams can generate a flicker in the signal. 06:24: Because there’s always an inherent uncertainty in any quantity, the phases of the two beams never really perfectly match up. 06:44: ... quantum fluctuations in the phase of the laser beams are larger than the change in the arm lengths due to ... 06:56: In this case, the complementary variables in question are not position and momentum, but rather phase and amplitude. 07:07: To improve our ability to detect faint gravitational waves we need to reduce the uncertainty in the phase of the laser beams. 07:35: ... can show this in so-called “phase-space”—in this case phase is plotted on the x-axis and amplitude is plotted on the y-axis—as a ... 08:03: ... phase space, this amounts to a shrinking of the uncertainty in one dimension, ... 08:22: In the case of LIGO, the phase of the light is squeezed - its precision increased - at the expense of increased uncertainty in amplitude. 08:30: This phase squeezing is achieved by using quantum entanglement. 08:43: Those outgoing photons have entangled phases - the relative positions of their peaks and troughs are correlated. 08:54: ... they’re recombined, they still have quantum fluctuations in the phase, but the fluctuations between the two beams are now correlated so that ... 09:05: Less flickering due to random phase shifts means that we can see real signals due to much weaker gravitational waves. 09:26: ... course there’s always a price - you pay for the improved phase precision with more uncertainty in the number of photons traveling in ... 09:43: But that noise is less of a problem than the phase uncertainty, at least for the higher frequency gravitational waves. 09:26: ... course there’s always a price - you pay for the improved phase precision with more uncertainty in the number of photons traveling in your laser ... 06:11: Phase refers to the relative positions of the peaks and troughs of the waves. 09:05: Less flickering due to random phase shifts means that we can see real signals due to much weaker gravitational waves. 08:03: ... phase space, this amounts to a shrinking of the uncertainty in one dimension, and a ... 08:30: This phase squeezing is achieved by using quantum entanglement. 09:43: But that noise is less of a problem than the phase uncertainty, at least for the higher frequency gravitational waves. 06:24: Because there’s always an inherent uncertainty in any quantity, the phases of the two beams never really perfectly match up. 08:43: Those outgoing photons have entangled phases - the relative positions of their peaks and troughs are correlated.
	2021-03-23: Zeno's Paradox & The Quantum Zeno Effect 10:09: We would say that the wavefunction for different electron states or quantum arrow positions are in phase with each other, or “coherent”. 15:21: ... black holes spiral towards each other, the frequency of the last phase of the inspiral is pretty uniquely determined by the so-called ...
	2021-02-17: Gravitational Wave Background Discovered? 00:00: ... expansion and huge gravitational waves would have been produced in the phase transition that ended inflation all of these space-time tsunamis would ...
	2020-12-22: Navigating with Quantum Entanglement 14:50: The Star may go through a phase as a white - or perhaps now black dwarf and will continue to evaporate due to proton decay.
	2020-12-15: The Supernova At The End of Time 02:39: ... the big bang, when one of these iron stars was in its extremely brief phase as a bright ball of hydrogen, bathing a young planetary system in the ...
	2020-11-18: The Arrow of Time and How to Reverse It 10:58: ... the universe went thorugh another phase transition - a vacuum decay - then the weak interaction would ...
	2020-11-04: Electroweak Theory and the Origin of the Fundamental Forces 05:07: Like all waves, the wavefunction has a phase - the current position of the peaks and troughs. 05:13: But that phase should be totally unobservable by any experiment. 05:18: ... Phase is what we call a degree of freedom, because it should be possible to ... 05:42: So there we go - we insisted on a symmetry - that the Schrodinger equation is invariant to changes in the local phase of the wavefunction. 06:05: ... real and complex parts of the wavefunction by some amount, we shift the phase, a process which leaves the magnitude of the wavefunction ... 06:20: ... the magnitude of the wavefunction, and the rotation amount is our local phase ... 07:17: There, the single 2D vector could only change in its angle - its phase. 08:50: ... Schrodinger equation so that it would no longer be invariant to local phase ... 05:07: Like all waves, the wavefunction has a phase - the current position of the peaks and troughs. 06:20: ... the magnitude of the wavefunction, and the rotation amount is our local phase shift. ... 08:50: ... Schrodinger equation so that it would no longer be invariant to local phase shifts. ...
	2020-10-05: Venus May Have Life! 10:13: Perhaps microbes multiply in this phase.
	2020-09-21: Could Life Evolve Inside Stars? 02:42: They form during the phase transition from liquid to solid. 03:04: These may have been formed soon after the Big Bang when massive phase transitions swept across the universe. 03:11: These transitions were analogous to the phase transitions between states of matter - for example, water freezing into ice. 03:32: ... that more in the future, but for now the important thing is that these phase transitions could have resulted in different types of topological ... 02:42: They form during the phase transition from liquid to solid. 03:04: These may have been formed soon after the Big Bang when massive phase transitions swept across the universe. 03:11: These transitions were analogous to the phase transitions between states of matter - for example, water freezing into ice. 03:32: ... that more in the future, but for now the important thing is that these phase transitions could have resulted in different types of topological defects, just like ... 03:04: These may have been formed soon after the Big Bang when massive phase transitions swept across the universe.
	2020-09-08: The Truth About Beauty in Physics 04:17: ... shifts in time, space, angle, or something more abstract like the phase of the ...
	2020-08-24: Can Future Colliders Break the Standard Model? 08:22: ... been in the first off-line phase since 2018, with operations set to resume in 2021, and there’ll be ...
	2020-08-17: How Stars Destroy Each Other 08:44: ... side of the brown dwarf comes into our view, while the red, dim phase is when we are looking at its night ...
	2020-07-28: What is a Theory of Everything: Livestream 00:00: ... john archibald wheeler who who was told me that he went through three phases in life first it's all particles so that's not your quantum ...
	2020-07-20: The Boundary Between Black Holes & Neutron Stars 00:38: ... after event, the excitement is shifting from the holy-crap-we-did-it phase to giddy excitement about what we’re actually ...
	2020-05-11: How Luminiferous Aether Led to Relativity 05:08: ... perfectly, reinforcing each other. In between the waveforms are out of phase and so cancel out. We see exactly the same effect in a pair of expanding ...
	2020-04-14: Was the Milky Way a Quasar? 01:10: Our central black hole, Sagittarius A*, has been in a quiet or “inactive” phase for as long as we’ve been observing it. 01:49: ... field believe that all supermassive black holes went through violent AGN phases in the past — and that includes our very own Sagittarius ... 09:54: A mini AGN phase is triggered either by an influx of gas or by a random massive star getting too close to the black hole. 10:34: The energy from those outflows will eventually shut down the star formation, but in the early phase it can help kick it off. 01:49: ... field believe that all supermassive black holes went through violent AGN phases in the past — and that includes our very own Sagittarius ...
	2020-03-16: How Do Quantum States Manifest In The Classical World? 01:48: ... it last time - to observe a superposition there needs to be a knowable phase relation between two superposed states. But that doesn’t tell us why ... 09:28: ... it’s hidden in a superposition of the atom’s on-off status. Essentially, phase information got transfered from the electron to the atom. I won’t go ... 01:48: ... it last time - to observe a superposition there needs to be a knowable phase relation between two superposed states. But that doesn’t tell us why certain ...
	2020-03-03: Does Quantum Immortality Save Schrödinger's Cat? 13:48: ... first step in the decoherence chain, which ultimately spreads relative phase information to the environment in an irreversible ... 13:59: ... in the quantum eraser, we haven't reached true decoherence - relative phase information is spread across only two particles, and so decoherence is ... 14:54: ... don't necessarily decohere the light - instead they introduce small phase shifts that can blur out the interference pattern without destroying ...
	2020-02-24: How Decoherence Splits The Quantum Multiverse 03:11: ... and if the shape of the waves are the same, and if there’s a constant phase difference between them - the peaks and troughs either line up exactly ... 04:44: ... line up with the peaks of the other - the two waves are perfectly in phase with each ... 05:52: The key in this experiment is that all photons exit the slits with the same phase relationship. 05:59: In this case, the phases match perfectly when the wavefunction leaves the slits - peaks and troughs come out at the same time. 06:06: But it still works if they don’t match exactly, as long as we get the same relative phase offset between the two slits for every subsequent photon. 06:15: A constant phase offset will just shift the interference pattern to left or right on the screen. 06:21: So we have two parts of the wavefunction - two branches or alternate histories - that have a consistent phase relation between them. 07:03: These also have a known phase relation, so they have quantum coherence relative to each other. 07:49: To destroy coherence, all we need to do is to mess up that phase relation. 08:05: ... particles, and so the wavefunction leaving that slit picks up a random phase offset compared to the other ... 08:18: ... that emerging wavefunction can still interfere with itself - the random phase offset would just shift the pattern left or right for that ... 08:45: The key here is that we lost information about the relative phase, and so we lost the ability to see interference patterns. 10:27: Phase differences get introduced between the different branches of the increasingly complex wavefunction. 10:45: As those branches propagate along the wires there’s still a particular phase offset between them. 10:52: ... we knew what that phase offset was then we could cause these alternate histories to merge again ... 11:07: ... that phase offset becomes less and less knowable the further the wavefunction ... 12:59: ... maintain its coherence - we need to have information about the relative phases across the parts of the wavefunction that we’re interested ... 13:19: Any contact with the external environment causes the phase information to leak into that environment. 03:11: ... and if the shape of the waves are the same, and if there’s a constant phase difference between them - the peaks and troughs either line up exactly or have a ... 10:27: Phase differences get introduced between the different branches of the increasingly complex wavefunction. 06:06: But it still works if they don’t match exactly, as long as we get the same relative phase offset between the two slits for every subsequent photon. 06:15: A constant phase offset will just shift the interference pattern to left or right on the screen. 08:05: ... particles, and so the wavefunction leaving that slit picks up a random phase offset compared to the other ... 08:18: ... that emerging wavefunction can still interfere with itself - the random phase offset would just shift the pattern left or right for that ... 10:45: As those branches propagate along the wires there’s still a particular phase offset between them. 10:52: ... we knew what that phase offset was then we could cause these alternate histories to merge again - just ... 11:07: ... that phase offset becomes less and less knowable the further the wavefunction advances, ... 08:05: ... particles, and so the wavefunction leaving that slit picks up a random phase offset compared to the other ... 06:21: So we have two parts of the wavefunction - two branches or alternate histories - that have a consistent phase relation between them. 07:03: These also have a known phase relation, so they have quantum coherence relative to each other. 07:49: To destroy coherence, all we need to do is to mess up that phase relation. 05:52: The key in this experiment is that all photons exit the slits with the same phase relationship. 05:59: In this case, the phases match perfectly when the wavefunction leaves the slits - peaks and troughs come out at the same time. 12:59: ... maintain its coherence - we need to have information about the relative phases across the parts of the wavefunction that we’re interested ... 05:59: In this case, the phases match perfectly when the wavefunction leaves the slits - peaks and troughs come out at the same time.
	2020-02-11: Are Axions Dark Matter? 04:33: ... physical interpretations - but one way to describe it is that it’s a phase offset picked up by the quantum field as it moves between the different ...
	2020-01-20: Solving the Three Body Problem 10:30: ... and angular momentum of the system. The system explores what we call a phase space - a space of possible arrangements of position and velocity. Well, ... 11:21: ... pair. Stone and Leigh found that they could identify the regions of phase space where these ejections were likely - and by doing so they could map ... 10:30: ... and angular momentum of the system. The system explores what we call a phase space - a space of possible arrangements of position and velocity. Well, for a ... 11:21: ... pair. Stone and Leigh found that they could identify the regions of phase space where these ejections were likely - and by doing so they could map the ... 10:30: ... and angular momentum of the system. The system explores what we call a phase space - a space of possible arrangements of position and velocity. Well, for a ...
	2019-10-07: Black Hole Harmonics 02:37: This final phase is called the ring-down – an expression comes from the analogy with a bell.
	2019-08-19: What Happened Before the Big Bang? 04:16: Old inflation predicts empty firewall bubbles that look nothing like the early phase of our universe. 06:09: These theories predict phase transitions in the behavior of fields as the temperature of the universe changes.
	2019-08-06: What Caused the Big Bang? 09:21: Introduce an ice crystal or even a speck of dust to the water and it will quickly turn to ice. Now, that's a phase transition. 09:30: The inflaton field also undergoes a phase transition towards the new vacuum state. 09:21: Introduce an ice crystal or even a speck of dust to the water and it will quickly turn to ice. Now, that's a phase transition. 09:30: The inflaton field also undergoes a phase transition towards the new vacuum state.
	2019-06-06: The Alchemy of Neutron Star Collisions 00:34: ... by nuclear fusion in the cores of very massive stars during the last phases of their lives and that elements heavier than iron were synthesized in ...
	2019-05-16: The Cosmic Dark Ages 11:49: ... ages ended, and light absorbed from the first quasars tracks the last phases of the subsequent ...
	2019-05-01: The Real Science of the EHT Black Hole 02:03: So they arrive at a different part of their wave cycle – there’s a phase difference between them. 02:08: And that phase difference itself is different for light coming from different points on the sky. 02:13: ... we can measure that phase difference precisely, we can measure the angular separation between two ... 02:27: It resolves between two points on the sky if the separation between those points results in a relative phase shift of around one wavecycle. 02:03: So they arrive at a different part of their wave cycle – there’s a phase difference between them. 02:08: And that phase difference itself is different for light coming from different points on the sky. 02:13: ... we can measure that phase difference precisely, we can measure the angular separation between two points to a ... 02:27: It resolves between two points on the sky if the separation between those points results in a relative phase shift of around one wavecycle.
	2019-04-03: The Edge of an Infinite Universe 17:29: After some millions of years watching the galaxies fall apart, the last phase of the destruction of the solar system would happen pretty fast.
	2019-02-07: Sound Waves from the Beginning of Time 05:18: The baryons transitioned in phase from a plasma to a gas. 05:22: We call this phase transition event: We call this phase transition event: Recombination.
	2019-01-24: The Crisis in Cosmology 03:18: ...giant stars, during the last phases of their lives.
	2018-12-12: Quantum Physics in a Mirror Universe 00:02: ... to coordinate shifts in space-time and even the rather abstract phase of the wave function in quantum mechanics so it might be surprising to ...
	2018-11-07: Why String Theory is Right 08:11: So, we expect the phase of the quantum wave function to be a gauge symmetry of any quantum theory. 08:35: ... special corrective term to the Schrodinger equation that fixes these phase differences preserving local phase ... 11:07: ... as local phase invariance required us to add the electromagnetic field to the ... 08:35: ... special corrective term to the Schrodinger equation that fixes these phase differences preserving local phase ... 11:07: ... as local phase invariance required us to add the electromagnetic field to the Schrodinger ...
	2018-10-25: Will We Ever Find Alien Life? 11:36: Researchers argue that all emerging technological civilizations will go through this phase of massive access to potentially cataclysmic technology.
	2018-10-18: What are the Strings in String Theory? 06:04: Then the phases of the overlapping wave match in the right way, and that wavelength/frequency of the wave is enhanced.
	2018-09-12: How Much Information is in the Universe? 04:21: ... will be better to use the number of grid points in a quantum phase space, which includes position, but also other degrees of freedom, like ... 05:53: Let's say instead, you only need a single bit of information for every element in phase space that's occupied. 04:21: ... will be better to use the number of grid points in a quantum phase space, which includes position, but also other degrees of freedom, like ... 05:53: Let's say instead, you only need a single bit of information for every element in phase space that's occupied.
	2018-07-18: The Misunderstood Nature of Entropy 06:47: We call this space of properties a phase space. 06:49: And instead of particles being distributed through position space, a microstate is really defined by how energy is distributed through phase space. 06:58: The average distribution of individual particles in phase space defines the thermodynamic properties of the system. 08:14: For example, if we try to draw pictures or write words in phase space, this is where we get to a point of common confusion. 06:47: We call this space of properties a phase space. 06:49: And instead of particles being distributed through position space, a microstate is really defined by how energy is distributed through phase space. 06:58: The average distribution of individual particles in phase space defines the thermodynamic properties of the system. 08:14: For example, if we try to draw pictures or write words in phase space, this is where we get to a point of common confusion. 06:58: The average distribution of individual particles in phase space defines the thermodynamic properties of the system.
	2018-07-11: Quantum Invariance & The Origin of The Standard Model 03:56: These components oscillate in sync with each other, but they're offset, shifted in phase by a constant amount. 04:03: Phase is just the wave's current state in its up-down oscillation. 04:12: But it turns out that this value doesn't depend on phase. 04:28: The phase itself is fundamentally unobservable. 04:31: ... can shift phase by any amount and you wouldn't change the resulting position of the ... 04:47: We call this sort of transformation a global phase shift. 04:56: The equations of quantum mechanics have what we call global phase invariance. 05:02: Global phase is a gauge symmetry of the system. 05:09: ... time, we'll shift the phase by different amounts at different locations, while still keeping the ... 05:16: This position dependent phase shift is called a local phase shift, instead of a global phase shift. 05:21: We'll try this because, well, we already know that the magnitude squared of the wave function should still stay the same under local phase shifts. 05:32: A global phase shift looks like this, where all points move by the same amount. 05:38: ... if we do a local phase shift, say, only this point here, only that location changes, as if it ... 05:50: If you allow this sort of local phase shift, you can change each point in a different way and really mess up the wave function. 06:08: Among other things, messing with local phase really screws up our prediction for the particle's momentum. 06:19: Change the shape of that wave function with local phase shifts and you actually break conservation of momentum. 06:26: Local phase is not a gauge symmetry of the basic Schrodinger equation. 06:38: Just for funsies, maybe we can change the Schrodinger equation to find a version that really is invariant to local phase shifts. 06:57: ... operator that's specially designed to undo any mess we make to the phase of the wave ... 07:06: If we choose this term correctly, it absorbs any local changes we make to the phase. 07:34: ... we've discovered that the only way for particles to have local phase invariance is for us to introduce a new fundamental field that pervades ... 08:24: Any particle that has this kind of charge will interact with and be affected by the electromagnetic field and be granted local phase invariance. 08:35: In order to have this particular type of local phase invariance, particles must possess electric charge. 08:48: In this case, the symmetry is local phase invariance and the conserved quantity is electric charge. 09:41: It turns out that local phase invariance is just the simplest of the larger suite of gauge symmetries of the standard model. 04:56: The equations of quantum mechanics have what we call global phase invariance. 07:34: ... we've discovered that the only way for particles to have local phase invariance is for us to introduce a new fundamental field that pervades all of ... 08:24: Any particle that has this kind of charge will interact with and be affected by the electromagnetic field and be granted local phase invariance. 08:35: In order to have this particular type of local phase invariance, particles must possess electric charge. 08:48: In this case, the symmetry is local phase invariance and the conserved quantity is electric charge. 09:41: It turns out that local phase invariance is just the simplest of the larger suite of gauge symmetries of the standard model. 08:35: In order to have this particular type of local phase invariance, particles must possess electric charge. 04:47: We call this sort of transformation a global phase shift. 05:16: This position dependent phase shift is called a local phase shift, instead of a global phase shift. 05:32: A global phase shift looks like this, where all points move by the same amount. 05:38: ... if we do a local phase shift, say, only this point here, only that location changes, as if it were ... 05:50: If you allow this sort of local phase shift, you can change each point in a different way and really mess up the wave function. 05:21: We'll try this because, well, we already know that the magnitude squared of the wave function should still stay the same under local phase shifts. 06:19: Change the shape of that wave function with local phase shifts and you actually break conservation of momentum. 06:38: Just for funsies, maybe we can change the Schrodinger equation to find a version that really is invariant to local phase shifts.
	2018-07-04: Will A New Neutrino Change The Standard Model? 04:04: It's related to the direction in which the particle's phase shifts under rotations.
	2018-06-13: What Survives Inside A Black Hole? 12:47: It's encoded in the energy, phase, polarization, et cetera of the two gamma-ray photons that are created.
	2018-05-16: Noether's Theorem and The Symmetries of Reality 07:42: That symmetry is the phase of the quantum field. 07:45: ... can rotate the complex phase of an oscillation in a quantum field by any amount, and the observable ...
	2018-04-25: Black Hole Swarms 05:35: The brightest X-ray binaries are aggressively gobbling up their companion stars, but that ravenous phase probably doesn't last all that long. 05:44: X-ray binaries likely spend most of the time in a quieter phase, with the gas just trickling slowly from the companion star.
	2018-04-11: The Physics of Life (ft. It's Okay to be Smart & PBS Eons!) 06:11: Beneath the thick ice caps, there's the transition between the solid and liquid phases of water.
	2018-03-07: Should Space be Privatized? 11:48: ... dwarf, but without the dramatic cycle of shell burning and red giant phases that the sun will go ...
	2018-02-21: The Death of the Sun 05:48: It's been blasting its own mess into the solar system in great winds through both red giant phases. 06:56: The final red giant phase is brief, only a few tens of millions of years. 08:22: The habitable zone, the region with the right solar flux liquid water, will expand beyond Neptune's orbit in the first red giant phase. 08:41: During the helium burning phase, the habitable zone contracts again for 100 million years. 05:48: It's been blasting its own mess into the solar system in great winds through both red giant phases.
	2017-12-20: Extinction by Gamma-Ray Burst 07:20: It's a massive star in the last phase of its life, currently blasting off its outer shells into a pinwheel-like nebula.
	2017-12-06: Understanding the Uncertainty Principle with Quantum Fourier Series 04:24: ... can build a wave packet by adding frequency components with the right phases to destructively interfere everywhere except within a small ...
	2017-10-19: The Nature of Nothing 12:56: The point at which a substance changes phase depends on both temperature and pressure. 13:02: The higher the pressure, the higher the temperature of these phase changes. 12:56: The point at which a substance changes phase depends on both temperature and pressure.
	2017-10-04: When Quasars Collide STJC 03:59: ... is observed with radio telescopes on opposite sides of the planet, and phase differences in the incoming radio waves are used to find the origin of ...
	2017-09-20: The Future of Space Telescopes 11:52: Feinstein 100 asks whether a black hole forming in the death of a massive star first goes through a neutron star-like phase. 12:04: The final phase of the core of such a star is a giant ball of nickel and iron, held up briefly by electron degeneracy pressure.
	2017-08-16: Extraterrestrial Superstorms 05:13: The phase changes from gas to liquid to solid release latent heat that lifts the storm still higher.
	2017-07-19: The Real Star Wars 02:14: ICBMs follow the parabolic path dictated by gravity when they're between an initial boost phase and an optional final guided phase. 05:05: The excited electron releases its energy is a photon that exactly matches the phase and direction of the seed photon.
	2017-07-07: Feynman's Infinite Quantum Paths 07:01: This is equivalent to the wave function along those paths being perfectly out of phase when they reach the destination.
	2017-03-15: Time Crystals! 05:35: Yao et al.'s work was theoretical, but it involved numerical calculations that allowed them to draw a phase diagram. 05:43: This is sort of like the phase diagram of regular matter in which you plot pressure versus temperature. 05:48: Different materials become solid, liquid, gas, or plasma at different locations on that phase diagram. 05:54: The analogous phase diagram for time crystals plots interaction strength between atoms versus imperfection in the spin-flip driving signal. 07:36: ... both fit the predicted phase diagram, their time asymmetry melting when subjected to too much ... 05:35: Yao et al.'s work was theoretical, but it involved numerical calculations that allowed them to draw a phase diagram. 05:43: This is sort of like the phase diagram of regular matter in which you plot pressure versus temperature. 05:48: Different materials become solid, liquid, gas, or plasma at different locations on that phase diagram. 05:54: The analogous phase diagram for time crystals plots interaction strength between atoms versus imperfection in the spin-flip driving signal. 07:36: ... both fit the predicted phase diagram, their time asymmetry melting when subjected to too much perturbation or ...
	2017-03-01: The Treasures of Trappist-1 09:53: It's design phase is a little further along, and it'll see first light a few years earlier than EELT. 10:18: ... before Galileo made his famous observations of Jupiter's moons and the phases of ...
	2017-02-15: Telescopes of Tomorrow 00:06: Telescopes have come a long way since Galileo first fixed two lenses to a tube and discovered the moons of Jupiter and the phases of Venus.
	2017-01-25: Why Quasars are so Awesome 07:36: As galaxies coalesced, they went through starburst phases, producing new stars at insane rates.
	2016-11-02: Quantum Vortices and Superconductivity + Drake Equation Challenge Answers 00:21: These theoretical physicists pioneered work in the understanding of phase transitions of materials at temperatures close to absolute zero. 00:31: The familiar phase transitions happen due to heating or cooling of a material. 00:53: Thouless, Kosterlitz, and Haldane massively advanced our understanding of these quantum phases by showing how topology drives this weird behavior. 00:21: These theoretical physicists pioneered work in the understanding of phase transitions of materials at temperatures close to absolute zero. 00:31: The familiar phase transitions happen due to heating or cooling of a material. 00:53: Thouless, Kosterlitz, and Haldane massively advanced our understanding of these quantum phases by showing how topology drives this weird behavior.
	2016-09-07: Is There a Fifth Fundamental Force? + Quantum Eraser Answer 05:33: And this is because those photons have interference bands that are exactly out of phase.
	2016-08-24: Should We Build a Dyson Sphere? 05:41: Engineers are in the serious planning phases for all sorts of space-based assembly projects, including 3D printing of giant telescope mirrors. 13:53: ... the challenge question, the interference pattern of C has the opposite phase to that of D. Its peaks line up with D's valleys and vice ... 05:41: Engineers are in the serious planning phases for all sorts of space-based assembly projects, including 3D printing of giant telescope mirrors.
	2016-05-25: Is an Ice Age Coming? 00:48: Right now, we're in a brief interglacial phase-- a relatively summery stretch in which the glaciers have retreated. 10:33: We're in a long, stable, low-eccentricity phase.
	2016-05-18: Anti-gravity and the True Nature of Dark Energy 12:27: If the signal sent by laser, then the same phased array that projects the launched laser will also be able to spot the returning later signal.
	2016-05-04: Will Starshot's Insterstellar Journey Succeed? 04:58: It would be a ground-based phased array of mini lasers called a light beamer that will produce a combined 100 gigawatt beam.
	2016-04-13: Will the Universe Expand Forever? 11:15: But recent work has suggested that it might actually be formed in lower-mass stars like our sun after they enter the red giant phase.
	2016-02-11: LIGO's First Detection of Gravitational Waves! 03:17: And the last phase of the merger takes only a few minutes.
	2015-12-09: How to Build a Black Hole 02:51: ... 3D space or even 4D space time but, rather, in six dimensional quantum phase ... 03:15: ... the exact way that the matter of a neutron star fills this 6D quantum phase space depends on two important principles of quantum theory, the Pauli ... 03:48: Now, by place, I mean location in quantum phase space. 04:09: In the case of a neutron star, position momentum phase space is completely full of neutrons. 04:26: This weird state of matter where phase space is completely full-- we call it degenerate matter. 06:53: Phase space expands. 02:51: ... 3D space or even 4D space time but, rather, in six dimensional quantum phase space. ... 03:15: ... the exact way that the matter of a neutron star fills this 6D quantum phase space depends on two important principles of quantum theory, the Pauli ... 03:48: Now, by place, I mean location in quantum phase space. 04:09: In the case of a neutron star, position momentum phase space is completely full of neutrons. 04:26: This weird state of matter where phase space is completely full-- we call it degenerate matter. 06:53: Phase space expands. 03:15: ... the exact way that the matter of a neutron star fills this 6D quantum phase space depends on two important principles of quantum theory, the Pauli exclusion ... 06:53: Phase space expands.
	2015-06-17: How to Signal Aliens 01:27: ... they suggested that the optimal solution would be a phased array of many radio telescopes sending narrow pulses of high-powered ...
	2015-05-13: 9 NASA Technologies Shaping YOUR Future 04:36: Now, right now it's just in the prototype phase, being used for experimental physical therapy, but in 10 years, I'm going to be jacked.

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