Search PBS Space Time

What are you looking for?

	2022-10-12: The REAL Possibility of Mapping Alien Planets! 06:05: ... telescope is sent to do the work. The second   is the string of pearls option, in which many so-called small-sats are sent in a ... 10:07: ... the Sun.   Remember that the scientists called this  a string of pearls. That first cluster of   craft was the first pearl. ...
	2022-09-21: Science of the James Webb Telescope Explained! 13:29: Robin Saunders reminds us that there’s a relationship between gluon flux tubes and string theory. 13:37: ... string theory actually began as an attempt to understand QCD, before being ... 13:46: And asks whether the methods of string theory are being brought back to understanding gluons again? 13:56: The core mechanics of string theory were developed to describe the very stringy one-dimensional gluon bonds between quarks, particularly in mesons. 14:20: Quantum chromodynamics actually started to explain was going on, so it suplanted hadronic string theory. 14:28: ... as Robin notes, one of the vibrational modes of these strings looked like the graviton, so the entire theory was shrunk in size by ... 14:41: We explain everything in our string theory episodes. 14:45: ... now, decades later, with string theory still failing to produce a slam-dunk testable prediciton, people ... 13:29: Robin Saunders reminds us that there’s a relationship between gluon flux tubes and string theory. 13:37: ... string theory actually began as an attempt to understand QCD, before being abandoned ... 13:46: And asks whether the methods of string theory are being brought back to understanding gluons again? 13:56: The core mechanics of string theory were developed to describe the very stringy one-dimensional gluon bonds between quarks, particularly in mesons. 14:20: Quantum chromodynamics actually started to explain was going on, so it suplanted hadronic string theory. 14:41: We explain everything in our string theory episodes. 14:45: ... now, decades later, with string theory still failing to produce a slam-dunk testable prediciton, people are ... 14:41: We explain everything in our string theory episodes. 13:56: The core mechanics of string theory were developed to describe the very stringy one-dimensional gluon bonds between quarks, particularly in mesons. 14:28: ... as Robin notes, one of the vibrational modes of these strings looked like the graviton, so the entire theory was shrunk in size by ... 13:56: The core mechanics of string theory were developed to describe the very stringy one-dimensional gluon bonds between quarks, particularly in mesons.
	2022-06-22: Is Interstellar Travel Impossible? 18:03: And we even have ideas for black holes in theories of quantum gravity - for example, the fuzzball of string theory, which we did an episode on.
	2022-06-15: Can Wormholes Solve The Black Hole Information Paradox? 06:01: ... advanced form of this is AdS/CFT correspondence, a branch of string theory that reveals that a   particular type of universe with ... 07:24: ... tidal wave of math in these papers  pulls ideas from string theory, holography,   quantum field theory, and  quantum ... 11:25: ... had seen this equation. The island rule had already been derived in string theory.   The researchers were surprised to find  that ... 06:01: ... advanced form of this is AdS/CFT correspondence, a branch of string theory that reveals that a   particular type of universe with three ... 07:24: ... tidal wave of math in these papers  pulls ideas from string theory, holography,   quantum field theory, and  quantum ... 11:25: ... The researchers were surprised to find  that you don’t need string theory to   derive the island rule: all you need  is the ... 07:24: ... tidal wave of math in these papers  pulls ideas from string theory, holography,   quantum field theory, and  quantum computing to name a few ... 11:25: ... The researchers were surprised to find  that you don’t need string theory to   derive the island rule: all you need  is the gravitational path ... 06:54: ... using only general relativity  and accepted quantum mechanics - no string   theories attached. To be fair, these US teams, dubbed the ...
	2022-05-25: The Evolution of the Modern Milky Way Galaxy 11:10: ... it pulls it back down. Like  beating a drum or plucking a guitar string,   the stars oscillate up and down in the galactic  plane, making a ...
	2022-04-27: How the Higgs Mechanism Give Things Mass 11:37: ... and we saw how this can lead to the creation  of cosmic strings in a recent episode.   But cosmic strings are the perhaps ...
	2022-03-08: Is the Proxima System Our Best Hope For Another Earth? 16:48: And the one on cosmic strings - topological defects that may span the length of the universe. 18:27: OK, on to cosmic strings. 18:33: When those cosmic strings radiate gravitational waves, how is the Higgs field supposed to smooth itself out? 18:46: ... episode - the simple vortex of phase angles making a loop around the string - is the most simplistic version of this ... 19:20: Or are cosmic strings the only indication of a change in phase angle? 19:45: I don’t know how you’d do this besides observing a cosmic string, but I suspect there are ways. 19:51: ... Scoot asks whether cosmic strings could explain the filaments and voids in the large scale distribution of ... 20:03: So the answer is maybe to the first two - but only if cosmic strings influence the CMB. 20:12: ... strings may have had sufficient density at extremely early times to leave an ... 20:24: ... is defined by those density fluctuations, so in that sense cosmic strings could have influenced it - but not directly in the sense of cosmic ... 20:38: ... - extremely unlikely - in our most accepted understanding of cosmic strings there aren’t anywhere near enough of them to account for dark ... 18:46: ... episode - the simple vortex of phase angles making a loop around the string - is the most simplistic version of this ... 13:02: Nonetheless, we’re focusing in on a relatively stringent set of requirements for this exoplanet to be able to support life. 20:24: ... influenced it - but not directly in the sense of cosmic strings causing string-like structure in galaxy ... 16:48: And the one on cosmic strings - topological defects that may span the length of the universe. 18:27: OK, on to cosmic strings. 18:33: When those cosmic strings radiate gravitational waves, how is the Higgs field supposed to smooth itself out? 19:20: Or are cosmic strings the only indication of a change in phase angle? 19:51: ... Scoot asks whether cosmic strings could explain the filaments and voids in the large scale distribution of ... 20:03: So the answer is maybe to the first two - but only if cosmic strings influence the CMB. 20:12: ... strings may have had sufficient density at extremely early times to leave an ... 20:24: ... is defined by those density fluctuations, so in that sense cosmic strings could have influenced it - but not directly in the sense of cosmic ... 20:38: ... - extremely unlikely - in our most accepted understanding of cosmic strings there aren’t anywhere near enough of them to account for dark ... 16:48: And the one on cosmic strings - topological defects that may span the length of the universe. 20:24: ... could have influenced it - but not directly in the sense of cosmic strings causing string-like structure in galaxy ... 20:03: So the answer is maybe to the first two - but only if cosmic strings influence the CMB. 18:33: When those cosmic strings radiate gravitational waves, how is the Higgs field supposed to smooth itself out?
	2022-02-23: Are Cosmic Strings Cracks in the Universe? 00:00: ... defects stretching across the sky. These are   cosmic strings, and many physicists think that they have to exist, and that we can ... 00:58: ... formed from topological defects in the quantum fields, aka cosmic strings. They have subatomic   thickness but prodigious mass and they ... 05:59: ... met. Our ice cube forms sheets, but our  Higgs field formed strings. Remember   that the vacuum decayed in a random  direction ... 07:33: ... around a central line.   And that central line is our cosmic string. Other topological defects may be possible.   For example, a ... 08:50: ... horizon,   potentially leading to dozens of cosmic  strings in a network across the universe.   Unlike the topological defects ... 10:09: ... occurs, a pair of “kinks” is formed in each of the newly formed strings speed   away from each other along the string at near ... 12:19: ... give us the data that we need to find these. Now if we do find a cosmic string, there’s one   other point of confusion we’d need to ... 08:50: ... or they switch partners - they intercommute.   If a straight string collides with itself it can  cut out a loop. Then, if the loop intersects ... 12:19: ... best - dare I say only - evidence to date in   support of string theory. We also expect  cosmic superstrings to decay less ... 10:09: ... images or even a   ring surrounding that lens. A cosmic string would also deflect light towards itself, but that can   only lead to a ... 12:19: ... or is it a cosmic   superstring? You’ve probably heard of string  theory - we’ve certainly talked about it enough   on this ... 00:00: ... defects stretching across the sky. These are   cosmic strings, and many physicists think that they have to exist, and that we can ... 00:58: ... formed from topological defects in the quantum fields, aka cosmic strings. They have subatomic   thickness but prodigious mass and they ... 05:59: ... met. Our ice cube forms sheets, but our  Higgs field formed strings. Remember   that the vacuum decayed in a random  direction ... 08:50: ... horizon,   potentially leading to dozens of cosmic  strings in a network across the universe.   Unlike the topological defects ... 10:09: ... occurs, a pair of “kinks” is formed in each of the newly formed strings speed   away from each other along the string at near ... 12:19: ... these subatomic 1-dimensional filaments called,  fittingly, strings. The strings of string theory   have nothing to do with the ... 10:09: ... radiating kinks in cosmic strings.   The other way to spot cosmic strings also  relies on a gravitational effect: gravitational   lensing - ... 00:58: ... And it’s the freezing of this field that can give us our cosmic strings.   Now a quantum field is just some numerical  property that the ... 10:09: ... tell-tale signals from gravitationally radiating kinks in cosmic strings.   The other way to spot cosmic strings also  relies on a ... 05:59: ... met. Our ice cube forms sheets, but our  Higgs field formed strings. Remember   that the vacuum decayed in a random  direction towards this ... 10:09: ... occurs, a pair of “kinks” is formed in each of the newly formed strings speed   away from each other along the string at near the  speed of light. ... 12:19: ... waves and the lensing.   But there are differences. While cosmic strings  almost always intercommute when they collide,   cosmic ... 07:33: ... the first bawlings of the baby universe and woven some cosmic strings.   What do they look like and what do they do? Those  phase angles ... 12:19: ... wave signature.   Now we haven’t actually found cosmic strings or superstrings … yet. But our searches   have given us bounds on ...
	2022-02-10: The Nature of Space and Time AMA 00:03: ... theories of the theme some of them try to answer this theory doesn't string theory assumes that this that the stage is there that the the space ...
	2021-12-20: What Happens If A Black Hole Hits Earth? 16:33: ... the faller, it continues to exist - coded in the complexity of the string vibrations. It’s holographically projected into 2 spatial dimensions, ... 17:55: ... could be tested. Actually, this might be the most testable prediction of string theory. There are simulations that suggest that the gravitational waves ... 16:33: ... the faller, it continues to exist - coded in the complexity of the string vibrations. It’s holographically projected into 2 spatial dimensions, and in its ... 14:10: ... as an explanation for dark matter, and the one on fuzzballs - the stringy theory version of the black ... 16:33: ... Meanwhile from the perspective of a distant observer it becomes a stringy ... 14:10: ... as an explanation for dark matter, and the one on fuzzballs - the stringy theory version of the black ... 16:33: ... Meanwhile from the perspective of a distant observer it becomes a stringy ... 14:10: ... as an explanation for dark matter, and the one on fuzzballs - the stringy theory version of the black ...
	2021-12-10: 2021 End of Year AMA! 00:02: ... let's see how about this one from laz the creator if i held the purse strings to an unlimited science budget what wild experiments or projects ...
	2021-11-17: Are Black Holes Actually Fuzzballs? 00:13: But many physicists will tell you that the best way to fix broken physics is with string. 00:18: String theory, in fact. 00:20: ... in the black holes of string theory - fuzzballs - are perhaps even weirder than the regular type ... 05:28: Black hole paradoxes may be solved by string theory. 05:32: In string theory, black holes are not hairless at all - in fact all of those strings make them positively fuzzy. 05:43: First a spot of string theory. 05:52: ... string theory, all elementary particles are oscillations in 1-dimensional ... 06:01: ... String theory immediately solves the problem of the black hole singularity, ... 06:17: It turns out that though, that string theory can make sense of the black hole event horizon also. 06:22: ... 1996, when Andrew Strominger and Cumrun Vafa created a black hole using string theory - in theory-space, not ... 06:37: ... the number of possible configurations of stringy structures - the 1-D strings themselves and higher-dimensional structures called ... 07:04: The infinitesimal strings and branes of string theory might be the analog of the molecules that store the entropy of our room full of air. 07:13: ... it was a decisive step and it gave us a compelling reason to think that string theory might explain where the microstates of black holes ... 07:53: For instance, the profile of the radiation emitted by the strings precisely matched that of traditional Hawking radiation. 08:45: ... while he was exploring stringy black holes, Samir Mathur found that the strings that formed the black hole would increase in size as the strength of ... 08:55: In fact, if you have a bunch of strings dense enough to form a black hole in general relativity, it wouldn’t actually collapse. 09:02: Rather it would grow to produce an agglomerate of strings with the same radius as a classical black hole. 09:09: ... at all, but rather a real surface that looks like a tangled nightmare of strings and branes, like the hairball coughed up from some hyperdimensional ... 09:25: ... a fuzzball will see its constituents crushed into a soup of elementary strings. ... 09:52: The ability for strings to maintain structure in this extreme gravity comes down to an effect specific to string theory called fractionation. 10:02: ... tension of a string is inversely proportional to its length: tight rubber bands are ... 10:10: ... in string theory, when you merge a large number of strings, the tension of the ... 10:22: That means by crushing an enormous number of strings together, the resulting monstrosity can be stretched to enormous scales. 10:30: The normally Planck-length strings can therefore pile up into fuzzballs with sizes ranging from kilometers to light years. 12:20: In string theory we have extra compact dimensions - spatial dimensions that are coiled up on the Planck scale so we can’t see them. 13:00: ... emergence of fuzzballs in string theory radically changed our vision of what a black hole could be and ... 10:10: ... of the resulting object is effectively smaller than for each individual string - proportional to the number of strings ... 00:18: String theory, in fact. 00:20: ... in the black holes of string theory - fuzzballs - are perhaps even weirder than the regular type Einstein’s ... 05:28: Black hole paradoxes may be solved by string theory. 05:32: In string theory, black holes are not hairless at all - in fact all of those strings make them positively fuzzy. 05:43: First a spot of string theory. 05:52: ... string theory, all elementary particles are oscillations in 1-dimensional strands that ... 06:01: ... String theory immediately solves the problem of the black hole singularity, because ... 06:17: It turns out that though, that string theory can make sense of the black hole event horizon also. 06:22: ... 1996, when Andrew Strominger and Cumrun Vafa created a black hole using string theory - in theory-space, not ... 07:04: The infinitesimal strings and branes of string theory might be the analog of the molecules that store the entropy of our room full of air. 07:13: ... it was a decisive step and it gave us a compelling reason to think that string theory might explain where the microstates of black holes ... 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: ... in string theory, when you merge a large number of strings, the tension of the resulting ... 12:20: In string theory we have extra compact dimensions - spatial dimensions that are coiled up on the Planck scale so we can’t see them. 13:00: ... emergence of fuzzballs in string theory radically changed our vision of what a black hole could be and provided ... 00:20: ... in the black holes of string theory - fuzzballs - are perhaps even weirder than the regular type Einstein’s ... 06:22: ... 1996, when Andrew Strominger and Cumrun Vafa created a black hole using string theory - in theory-space, not ... 05:32: In string theory, black holes are not hairless at all - in fact all of those strings make them positively fuzzy. 09:52: The ability for strings to maintain structure in this extreme gravity comes down to an effect specific to string theory called fractionation. 13:00: ... emergence of fuzzballs in string theory radically changed our vision of what a black hole could be and provided a ... 06:37: ... the microstates on the horizon- the number of possible configurations of stringy structures - the 1-D strings themselves and higher-dimensional ... 08:00: This was another stunning match to theory, and also a way for stringy black holes to leak out their information. 08:06: ... pretty good, but I realize that I haven’t really told you what these stringy black holes look like, or how they form, or how structure can actually ... 08:45: ... while he was exploring stringy black holes, Samir Mathur found that the strings that formed the black ... 11:07: But if you approach the fuzzball you start to see this surface of stringy material with a thickness of about a Planck length. 11:35: ... a fuzzball is forming, all of the matter - now dissolved into stringy mess, is pushed up to the surface and the interior grid of spacetime is ... 05:32: In string theory, black holes are not hairless at all - in fact all of those strings make them positively fuzzy. 06:01: ... a single point, it gets distributed around the ring structure of these strings. ... 06:37: ... the number of possible configurations of stringy structures - the 1-D strings themselves and higher-dimensional structures called ... 07:04: The infinitesimal strings and branes of string theory might be the analog of the molecules that store the entropy of our room full of air. 07:53: For instance, the profile of the radiation emitted by the strings precisely matched that of traditional Hawking radiation. 08:45: ... while he was exploring stringy black holes, Samir Mathur found that the strings that formed the black hole would increase in size as the strength of ... 08:55: In fact, if you have a bunch of strings dense enough to form a black hole in general relativity, it wouldn’t actually collapse. 09:02: Rather it would grow to produce an agglomerate of strings with the same radius as a classical black hole. 09:09: ... at all, but rather a real surface that looks like a tangled nightmare of strings and branes, like the hairball coughed up from some hyperdimensional ... 09:25: ... a fuzzball will see its constituents crushed into a soup of elementary strings. ... 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: ... in string theory, when you merge a large number of strings, the tension of the resulting object is effectively smaller than for each ... 10:22: That means by crushing an enormous number of strings together, the resulting monstrosity can be stretched to enormous scales. 10:30: The normally Planck-length strings can therefore pile up into fuzzballs with sizes ranging from kilometers to light years. 08:55: In fact, if you have a bunch of strings dense enough to form a black hole in general relativity, it wouldn’t actually collapse. 10:10: ... smaller than for each individual string - proportional to the number of strings merged. ... 07:53: For instance, the profile of the radiation emitted by the strings precisely matched that of traditional Hawking radiation. 12:17: Now let’s try a string-theoretic version. 06:37: ... the microstates on the horizon- the number of possible configurations of stringy structures - the 1-D strings themselves and higher-dimensional ... 08:00: This was another stunning match to theory, and also a way for stringy black holes to leak out their information. 08:06: ... pretty good, but I realize that I haven’t really told you what these stringy black holes look like, or how they form, or how structure can actually ... 08:45: ... while he was exploring stringy black holes, Samir Mathur found that the strings that formed the black ... 11:07: But if you approach the fuzzball you start to see this surface of stringy material with a thickness of about a Planck length. 11:35: ... a fuzzball is forming, all of the matter - now dissolved into stringy mess, is pushed up to the surface and the interior grid of spacetime is ... 08:00: This was another stunning match to theory, and also a way for stringy black holes to leak out their information. 08:06: ... pretty good, but I realize that I haven’t really told you what these stringy black holes look like, or how they form, or how structure can actually be ... 08:45: ... while he was exploring stringy black holes, Samir Mathur found that the strings that formed the black hole ... 08:00: This was another stunning match to theory, and also a way for stringy black holes to leak out their information. 08:06: ... pretty good, but I realize that I haven’t really told you what these stringy black holes look like, or how they form, or how structure can actually be supported ... 08:45: ... while he was exploring stringy black holes, Samir Mathur found that the strings that formed the black hole would ... 11:07: But if you approach the fuzzball you start to see this surface of stringy material with a thickness of about a Planck length. 11:35: ... a fuzzball is forming, all of the matter - now dissolved into stringy mess, is pushed up to the surface and the interior grid of spacetime is ... 06:37: ... the microstates on the horizon- the number of possible configurations of stringy structures - the 1-D strings themselves and higher-dimensional structures called ...
	2021-10-05: Why Magnetic Monopoles SHOULD Exist 06:30: ... construction is called the “Dirac string”, and Dirac’s argument is that if the string part of the Dirac string is ... 06:43: The second part of the argument is under what conditions that string is undetectable. 06:57: Imagine a charged particle - say an electron - passing by a Dirac string. 07:02: To plot that trajectory you add up all possible paths of the electron, including paths to the left and to the right at the string. 07:09: ... presence of the string, with its magnetic fields, should introduce different phase shifts ... 07:22: In other words, the string would be detectable. 07:24: But there’s one scenario where the string can never be detected. 07:34: ... that charge, the phase shift induced between the different sides of the string is exactly one wave cycle - which means no observable ... 07:42: ... for the Dirac string to be undetectable then electric charge can only exist in integer ... 07:56: ... the upshot is that the string connecting monopoles is fundamentally unobservable, and Dirac argued ... 17:56: Physicists hope to understand these things someday, perhaps with twistor or string theory. 07:56: ... the upshot is that the string connecting monopoles is fundamentally unobservable, and Dirac argued that this ... 17:56: Physicists hope to understand these things someday, perhaps with twistor or string theory.
	2021-05-11: How To Know If It's Aliens 18:32: ... hurt to check. I like this a lot. Looking for dark matter in, say, string theory, before you check whether it’s black holes is like looking for ...
	2021-02-17: Gravitational Wave Background Discovered? 00:00: ... gravitational waves and there are theoretical sources also cosmic strings topological seams in the fabric of space would produce waves when their ...
	2021-01-12: What Happens During a Quantum Jump? 05:10: He argued that the same emission spectra could be got by thinking of these levels as fundamental vibrational modes, like on a drum or guitar string.
	2020-10-05: Venus May Have Life! 13:48: And, ultimately, to ally with them in war against the cosmic string entities in the heart of the Sun that we discussed recently.
	2020-09-28: Solving Quantum Cryptography 09:52: Suppose Alice wants to send a message to Bob—”CAT” which is represented by the binary string 1 1 0 1. 14:24: Last week we talked about a highly speculative idea - lifeforms inside stars, formed from cosmic strings and magnetic monopoles. 09:52: Suppose Alice wants to send a message to Bob—”CAT” which is represented by the binary string 1 1 0 1. 14:24: Last week we talked about a highly speculative idea - lifeforms inside stars, formed from cosmic strings and magnetic monopoles.
	2020-09-21: Could Life Evolve Inside Stars? 00:16: Oh, and here’s an extra crazy one - life composed of cosmic strings and magnetic monopoles, evolving in the hearts of stars. 01:03: ... fundamental kinks and defects in the fabric of the universe - cosmic strings beaded with magnetic monopoles - may evolve into complex structures, and ... 01:28: What exactly are cosmic strings and magnetic monopoles? 01:38: Cosmic strings and magnetic monopoles are what we call topological defects. 03:56: A 1-D topological defect is a cosmic string - an extremely thin filament. 04:10: We’re interested in the strings and monopoles for now. 04:14: In certain theoretical scenarios, a monopole can be connected to the end of a string - or two strings, actually. 06:29: With semipoles, it’s possible to form string segments capped by NON-annihilating semipole pairs that actually repel each other. 06:36: In this way, it may be possible to develop complex string structures, analogous to chemistry. 07:00: Others have speculated that cosmic strings may get trapped inside stars in the process of star formation. 09:50: ... going to have to get a much better understanding of cosmic strings and monopoles - and, you know, actually verify that they exist in the ... 11:28: ... those who don't know, James is a higher being composed of cosmic strings and monopoles, visiting Earth from the core of the Sun to help spread ... 03:56: A 1-D topological defect is a cosmic string - an extremely thin filament. 04:14: In certain theoretical scenarios, a monopole can be connected to the end of a string - or two strings, actually. 06:29: With semipoles, it’s possible to form string segments capped by NON-annihilating semipole pairs that actually repel each other. 06:36: In this way, it may be possible to develop complex string structures, analogous to chemistry. 05:31: Can these string-monopole necklaces store information? 00:16: Oh, and here’s an extra crazy one - life composed of cosmic strings and magnetic monopoles, evolving in the hearts of stars. 01:03: ... fundamental kinks and defects in the fabric of the universe - cosmic strings beaded with magnetic monopoles - may evolve into complex structures, and ... 01:28: What exactly are cosmic strings and magnetic monopoles? 01:38: Cosmic strings and magnetic monopoles are what we call topological defects. 04:10: We’re interested in the strings and monopoles for now. 04:14: In certain theoretical scenarios, a monopole can be connected to the end of a string - or two strings, actually. 07:00: Others have speculated that cosmic strings may get trapped inside stars in the process of star formation. 09:50: ... going to have to get a much better understanding of cosmic strings and monopoles - and, you know, actually verify that they exist in the ... 11:28: ... those who don't know, James is a higher being composed of cosmic strings and monopoles, visiting Earth from the core of the Sun to help spread ... 01:03: ... fundamental kinks and defects in the fabric of the universe - cosmic strings beaded with magnetic monopoles - may evolve into complex structures, and even ...
	2020-09-08: The Truth About Beauty in Physics 00:37: ... it’s also been argued that modern theoretical physics, and in particular string theory, has been overly transfixed by the allure of beauty for decades, ... 10:44: So now we come to string theory. 10:46: The first compellingly beautiful aspect of string theory is that gravity, in the form of the Einstein field equations - automatically emerged from it. 10:54: But there are other things too - for example, disparate versions of string theory seem to miraculously converge into one master theory. 11:05: String theorists find their math beautiful, even if it is far from being simple. 11:15: So did string theory fall for the same sort of misguided obsession with beauty as did Weyl? 12:11: And so perhaps the mathematical wonders of string theory DO reflect something true about reality, but we’re struggling with how to interpret it all. 11:05: String theorists find their math beautiful, even if it is far from being simple. 00:37: ... it’s also been argued that modern theoretical physics, and in particular string theory, has been overly transfixed by the allure of beauty for decades, and that ... 10:44: So now we come to string theory. 10:46: The first compellingly beautiful aspect of string theory is that gravity, in the form of the Einstein field equations - automatically emerged from it. 10:54: But there are other things too - for example, disparate versions of string theory seem to miraculously converge into one master theory. 11:15: So did string theory fall for the same sort of misguided obsession with beauty as did Weyl? 12:11: And so perhaps the mathematical wonders of string theory DO reflect something true about reality, but we’re struggling with how to interpret it all. 11:15: So did string theory fall for the same sort of misguided obsession with beauty as did Weyl?
	2020-08-10: Theory of Everything Controversies: Livestream 00:00: ... today from loop quantum gravity which is one of the founders to string theory to the foundations of quantum mechanics and the philosophy of ...
	2020-07-28: What is a Theory of Everything: Livestream 00:00: ... physicist with really a hugely broad range of interests including string theory and loop quantum gravity in principle we could do this entire ...
	2020-07-08: Does Antimatter Explain Why There's Something Rather Than Nothing? 04:48: ... So, if there exists some underlying more fundamental theory, maybe string theory for example, then CPT symmetry may no longer be a foregone ...
	2020-05-27: Does Gravity Require Extra Dimensions? 05:57: ... most famous example of compactified extra dimensions is in string theory, and in modern superstring theory there are 6 additional spatial ... 06:10: ... the idea of compact extra dimensions is much older than string theory - first proposed by Oscar Klein in the 1920s as part of what ... 11:32: ... near being able to probe the size-scale of the extra dimensions from string theory though, and so string theorists can keep on ... 13:29: ... black hole - regions like the Carter time machine and the infinite string of parallel ... 15:33: ... the string of universes through the rotating Kerr black hole requires the ... 15:44: ... Polygondwanaland: in reality, impossible-seeming things like an infinite string of universes or a time machine indicate that the math may have led our ... 11:32: ... the size-scale of the extra dimensions from string theory though, and so string theorists can keep on ... 05:57: ... most famous example of compactified extra dimensions is in string theory, and in modern superstring theory there are 6 additional spatial ... 06:10: ... the idea of compact extra dimensions is much older than string theory - first proposed by Oscar Klein in the 1920s as part of what became ... 11:32: ... near being able to probe the size-scale of the extra dimensions from string theory though, and so string theorists can keep on ... 06:10: ... the idea of compact extra dimensions is much older than string theory - first proposed by Oscar Klein in the 1920s as part of what became ...
	2020-05-11: How Luminiferous Aether Led to Relativity 03:25: ... a wave on a string: each string segment moves up and down only, tugging on neighboring ...
	2020-04-28: Space Time Livestream: Ask Matt Anything 00:00: ... stuff as well I was certainly dreaming about quantum with gravity and string theory when we were writing those episodes so so it varies massively ...
	2020-02-03: Are there Infinite Versions of You? 11:39: ... duplicate region of the universe where Shakespeare’s plays are just long strings of S’s underscored with fecal smears - and where the infinite monkey ...
	2020-01-27: Hacking the Nature of Reality 11:24: Other physicists quickly realised that it was telling us that mesons could be described by a very particular type physical system: a vibrating string. 11:35: ... so string theory was born - at first as a description of strong nuclear force ...
	2019-12-17: Do Black Holes Create New Universes? 04:27: Perhaps the configuration of the geometry string theory’s extra dimensions gets shifted - this would do the job.
	2019-12-09: The Doomsday Argument 01:57: ... number of theories in physics from string theory to eternal inflation predict that the cosmological constant could ... 12:57: ... a special thanks we pulled a few strings and got you moved over to the doom-never box . If anyone wishes to join ... 01:57: ... number of theories in physics from string theory to eternal inflation predict that the cosmological constant could take ... 12:57: ... a special thanks we pulled a few strings and got you moved over to the doom-never box . If anyone wishes to join ...
	2019-11-11: Does Life Need a Multiverse to Exist? 11:24: ... example we have string theory: this candidate theory of everything suggests that the values of ...
	2019-11-04: Why We Might Be Alone in the Universe 12:30: A few of you wondered if there's a connection between the loops of loop quantum gravity and the closed strings of string theory. 12:39: The strings of string theory have a somewhat physical interpretation - the fact that they can hold energy and vibrate and exist in space. 12:30: A few of you wondered if there's a connection between the loops of loop quantum gravity and the closed strings of string theory. 12:39: The strings of string theory have a somewhat physical interpretation - the fact that they can hold energy and vibrate and exist in space. 12:30: A few of you wondered if there's a connection between the loops of loop quantum gravity and the closed strings of string theory. 12:39: The strings of string theory have a somewhat physical interpretation - the fact that they can hold energy and vibrate and exist in space.
	2019-10-15: Loop Quantum Gravity Explained 00:06: And can it really defeat string theory in our quest for a Theory of Everything? 00:32: ... it quite a bit already, including what’s probably the lead contender - string ... 00:42: But string theory isn’t the only game in town - or so some physicists believe. 00:47: ... gravity that avoids a lot of conceptual baggage like tiny wiggling strings made of coiled up extra ... 02:54: In string theory, a type of background independence emerges in an abstract space of moving strings and with that comes a gravitational field. 03:04: But for that to work first you need those strings to exist - and we don’t know if they do. 03:10: ... quantum gravity tries to quantize general relativity with no strings attached, while preserving the background independence already inherent ... 11:13: And without adding big assumptions – like the existence of strings or extra dimensions or supersymmetry. 13:16: Loop quantum gravity is an intriguing alternative to the more popular string theory. 00:06: And can it really defeat string theory in our quest for a Theory of Everything? 00:32: ... it quite a bit already, including what’s probably the lead contender - string theory. ... 00:42: But string theory isn’t the only game in town - or so some physicists believe. 02:54: In string theory, a type of background independence emerges in an abstract space of moving strings and with that comes a gravitational field. 13:16: Loop quantum gravity is an intriguing alternative to the more popular string theory. 00:42: But string theory isn’t the only game in town - or so some physicists believe. 00:47: ... gravity that avoids a lot of conceptual baggage like tiny wiggling strings made of coiled up extra ... 02:54: In string theory, a type of background independence emerges in an abstract space of moving strings and with that comes a gravitational field. 03:04: But for that to work first you need those strings to exist - and we don’t know if they do. 03:10: ... quantum gravity tries to quantize general relativity with no strings attached, while preserving the background independence already inherent ... 11:13: And without adding big assumptions – like the existence of strings or extra dimensions or supersymmetry. 03:10: ... quantum gravity tries to quantize general relativity with no strings attached, while preserving the background independence already inherent to ...
	2019-10-07: Black Hole Harmonics 03:02: ... or a black hole – are analogous to the harmonics of a vibrating guitar string or piano ... 03:12: In the latter cases we can describe a vibrating string as a series of standing sine waves of different frequencies, all happening at the same time. 03:22: ... lowest frequency the string can support is called the fundamental mode – it’s usually the strongest ... 03:40: The full set of possible frequencies a string can support are called its harmonics.
	2019-09-30: How Many Universes Are There? 07:20: People have also invoked the anthropic principle plus eternal inflation to explain a conundrum in string theory. 07:27: ... we’ve talked about before, modern string theory is difficult to pin down because there are countless possible ... 07:46: The vast space of possible configurations of these compact dimensions is referred to as the string landscape. 08:01: We don’t know why our universe has the particular string vacuum state that it does. 08:14: Enter the anthropic principle once again: eternal inflation gives us enough universes to easily populate the entire string landscape. 07:46: The vast space of possible configurations of these compact dimensions is referred to as the string landscape. 08:14: Enter the anthropic principle once again: eternal inflation gives us enough universes to easily populate the entire string landscape. 07:20: People have also invoked the anthropic principle plus eternal inflation to explain a conundrum in string theory. 07:27: ... we’ve talked about before, modern string theory is difficult to pin down because there are countless possible ... 08:01: We don’t know why our universe has the particular string vacuum state that it does.
	2019-08-19: What Happened Before the Big Bang? 06:04: As well as theories which also unify gravity, like string theory. 10:04: ... are also deep possible connections between inflation and string theory and with the holographic principle, as described in one of ... 06:04: As well as theories which also unify gravity, like string theory. 10:04: ... are also deep possible connections between inflation and string theory and with the holographic principle, as described in one of Stephen ...
	2019-07-18: Did Time Start at the Big Bang? 09:52: ... there isn't anywhere near enough matter to do that unless we bring in string theory the Steinhardt-Turok model suggests that our universe floats in a ...
	2019-05-09: Why Quantum Computing Requires Quantum Cryptography 07:43: ... generates a random string of bits, 0’s and 1’s and encodes these bits using photons polarized in a ...
	2019-04-10: The Holographic Universe Explained 01:02: We’ve moved from quantum field theory to black hole thermodynamics to string theory. 04:06: ... laid out the first steps towards how this could be achieved using string theory, but ultimately it was Juan Maldacena who figured out a concrete ... 04:26: Let’s ignore string theory for the moment and just think about how to create an extra dimension. 05:53: We also see it in string theory, which I’ll come back to. 07:42: But for the details we need string theory. 07:47: Even from the beginning string theory had hints of this scale invariance and dimensional weirdness. 07:54: ... quarks – mesons – as this strand of gluons that behaves like a vibrating string. ... 08:15: That means you can pretend string length-slash-energy is a separate dimension as a calculation trick. 08:44: This and other glitches led to string theory being abandoned as a model for the strong force. 08:49: ... to make it a theory of quantum gravity, and the scale invariance of the strings becoming a central feature of string ... 09:02: We now have a several versions string theory that try to explain how vibrating strings can lead to the familiar particles of this universe. 09:10: These were tentatively united by Ed Witten’s M-theory, which showed that different types of string and string theories were all related by dualities. 09:27: These arose from the way string size and energy scales could be rescaled. 09:34: But the strangest string duality was still to come with AdS/CFT correspondence, proposed by Argentinean physicist Juan Maldecena in 1997. 09:52: Maldecena imagined a set of string theory objects called branes. 09:57: These are like multidimensional strings that can serve as start and end points for strings, but also as spaces embedded within higher-dimensions. 10:15: The strings connected to these branes are scale invariant, so their length and energy can vary without changing the physics. 10:57: This quality fcame from the energy-scale-invariance of the strings embedded in the construction of this space. 11:38: As with the other dualities in string theory, this one was extremely useful for calculations. 15:28: ... AdS/CFT correspondence, the volume exhibits gravity via a type of string theory, while the surface exhibits no gravity - only a quantum field ... 09:34: But the strangest string duality was still to come with AdS/CFT correspondence, proposed by Argentinean physicist Juan Maldecena in 1997. 08:15: That means you can pretend string length-slash-energy is a separate dimension as a calculation trick. 09:27: These arose from the way string size and energy scales could be rescaled. 04:06: ... theory, but ultimately it was Juan Maldacena who figured out a concrete string theoretic realization of the holographic principle with AdS/CFT ... 09:10: These were tentatively united by Ed Witten’s M-theory, which showed that different types of string and string theories were all related by dualities. 01:02: We’ve moved from quantum field theory to black hole thermodynamics to string theory. 04:06: ... laid out the first steps towards how this could be achieved using string theory, but ultimately it was Juan Maldacena who figured out a concrete string ... 04:26: Let’s ignore string theory for the moment and just think about how to create an extra dimension. 05:53: We also see it in string theory, which I’ll come back to. 07:42: But for the details we need string theory. 07:47: Even from the beginning string theory had hints of this scale invariance and dimensional weirdness. 08:44: This and other glitches led to string theory being abandoned as a model for the strong force. 08:49: ... and the scale invariance of the strings becoming a central feature of string theory. ... 09:02: We now have a several versions string theory that try to explain how vibrating strings can lead to the familiar particles of this universe. 09:52: Maldecena imagined a set of string theory objects called branes. 11:38: As with the other dualities in string theory, this one was extremely useful for calculations. 15:28: ... AdS/CFT correspondence, the volume exhibits gravity via a type of string theory, while the surface exhibits no gravity - only a quantum field theory ... 09:52: Maldecena imagined a set of string theory objects called branes. 08:49: ... to make it a theory of quantum gravity, and the scale invariance of the strings becoming a central feature of string ... 09:02: We now have a several versions string theory that try to explain how vibrating strings can lead to the familiar particles of this universe. 09:57: These are like multidimensional strings that can serve as start and end points for strings, but also as spaces embedded within higher-dimensions. 10:15: The strings connected to these branes are scale invariant, so their length and energy can vary without changing the physics. 10:57: This quality fcame from the energy-scale-invariance of the strings embedded in the construction of this space. 10:15: The strings connected to these branes are scale invariant, so their length and energy can vary without changing the physics. 10:57: This quality fcame from the energy-scale-invariance of the strings embedded in the construction of this space. 11:04: In good string-theorist style, Maldacena defined incorporated that scale factor into be a new spatial dimension.
	2019-04-03: The Edge of an Infinite Universe 14:20: That structure looked exactly like a string theory with gravity and everything.
	2019-01-16: Our Antimatter, Mirrored, Time-Reversed Universe 13:52: ... inverted version of Canada. The last episode before the break was, "Why string theory is Wrong". Today, I want to address the comments to that episode ... 15:29: ... if it provides an answer to the hierarchy problem and gives us super string theory it will be odd if supersymmetry existed as part of super string ... 16:06: ... other point is that the large undefined parameter space of string theory - the so called 'String landscape' is no more of a problem for ... 16:49: ... or wrongness. FieldStrength's final point is that the untestability of string theory is connected to the extreme energy scale of quantum gravity and ... 17:15: ... yeah string theory is apparently not yet testable, but I disagree with those who say ... 16:06: ... the large undefined parameter space of string theory - the so called 'String landscape' is no more of a problem for string theory than it is for the standard ... 13:52: ... inverted version of Canada. The last episode before the break was, "Why string theory is Wrong". Today, I want to address the comments to that episode or ... 15:29: ... if it provides an answer to the hierarchy problem and gives us super string theory it will be odd if supersymmetry existed as part of super string theory ... 16:06: ... other point is that the large undefined parameter space of string theory - the so called 'String landscape' is no more of a problem for string ... 16:49: ... or wrongness. FieldStrength's final point is that the untestability of string theory is connected to the extreme energy scale of quantum gravity and that ... 17:15: ... yeah string theory is apparently not yet testable, but I disagree with those who say that ... 16:06: ... other point is that the large undefined parameter space of string theory - the so called 'String landscape' is no more of a problem for string ... 13:52: ... provide a neat resolution to the standard models hierarchy problem but string theory doesn't require supersymmetry to be at that scale at all for the purpose of ...
	2019-01-09: Are Dark Matter And Dark Energy The Same? 12:07: Which is good for string theorists, as Farnes notes, but not for observers because that’s not consistent with what we see.
	2018-12-20: Why String Theory is Wrong 00:13: String theory is certainly beautiful in the eyes of many physicists, but is it beautiful enough to pursue even if it's wrong? 01:03: Could this also be the case with string theory? 01:06: ... idea did work when translated to the very particular case of a quantum string, which is part of what got string theory going in the first ... 01:18: We talked about this in detail in our episode on why string theory is right. 01:23: Which itself was a sequel to our primer on the basics of string theory. 01:27: In those episodes, we saw some of the remarkable ways that string theory promised to converge on a theory of everything. 01:35: ... under one umbrella, and there's also the convergence of many versions of string theory into a single picture with a very specific number of extra ... 01:55: ... of this promise of being so right do more and more physicists think that string theory is after all either woefully incomplete or just plain ... 02:07: Modern string theory is the convergence of many beautiful ideas in physics, each of which feel right in their own way. 02:14: ... see where string theory ultimately fails, we need to rewind to look at some of these a ... 04:57: These may have seemed like fatal flaws, but we can thank this wrongness for the later development of string theory. 05:07: For example, adding more compact dimensions of various shapes and, of course, strings. 05:16: String theory is just the most famous. 05:18: So, start with Kaluza-Klein, add vibrating strings and exactly the right extra special dimensions, and you have string theory. 05:40: It also introduces fermions to the boson only version of string theory to give super string theory. 06:03: Superstring started out with incredible promise, and so there was a proliferation of different versions of super string theory. 06:20: Five different approaches to getting all of the desired particles out of the basic premise of strings wiggling in ten dimensions. 06:32: What differs is the detailed geometries and symmetries of those spaces, and the way strings vibrate within them. 07:12: These dualities reveal that certain classes of string theory were actually the different ways of expressing exactly the same theory. 07:20: Perhaps there was a glimmer of hope for these divergent versions of string theory after all. 07:50: Our tiny quantum strings can roam that small dimension. 08:01: ... number of times a string winds around this compactified dimension is called its winding number. ... 08:17: These strings are vibrating with standing waves like guitar strings, and their energy also depends on the frequency of that vibration. 08:25: That frequency depends on the density of wave cycles on the string. 08:30: ... divided by the radius. So, there are two ways to get a high-energy string: have a large winding number along with a large radius that gives you a ... 08:55: ... radius can be used to define the momentum of a particle produced by this string. ... 09:19: ... sounds weird but this may just have saved string theory. I just described a type of duality, in this case t-duality, ... 09:48: T-dualities prove that some of these different versions of string theory are actually different expressions of the same theory. 09:54: The other main type of duality in string theory is s-duality, strong-weak duality. 09:59: In this case it's a duality between strongly versus weakly interacting strings. This seems even more contradictory, but it's incredibly powerful. 10:18: S-duality provided the final linchpin that demonstrated that the five different types of string theory were all manifestations of the same theory. 10:31: ... a string conference in '95, Witten showed that the disparate string theories were ... 10:51: ... that it adds a single extra dimension, to connect all of the five super string theory types via ... 11:41: See, in parallel to the development of super string theory, other physicists have been working on super gravity. 11:49: ... Super gravity should be the low energy, large-scale limit to super string theory. So it was incredibly exciting that string theory appeared to ... 12:14: ... with each other and with super gravity restored the sense of beauty to string theory. It appeared to be on the track to rightness once again, so So ... 12:53: The behavior of strings in these hyper dimensional surfaces is only understood in idealized cases. 13:08: ... 500 different topologies, the actual number is a lot higher. This is the string landscape. Each geometry for the compactified dimensions implies a ... 13:44: ... principle the standard model lives somewhere in the string landscape, but without knowing the geometry of the extra dimensions, ... 14:00: Essentially all string theories require supersymmetry in order to work. 14:16: But string theories are still rightly concerned. Their elegant theory which was converging so beautifully has stalled. 14:55: So perhaps string theorists should also stick to their guns. 15:00: ... wrong or incomplete as current string theory may be, it may also be the inevitable early step as we seek an ... 15:14: ... the physics required to understand string theory is tough thankfully there are online tools that can help like ... 10:31: ... a string conference in '95, Witten showed that the disparate string theories were all just ... 08:01: ... dimension is called its winding number. The energy of such a string depends on the winding number times the radius of the compactified dimension. ... 13:08: ... 500 different topologies, the actual number is a lot higher. This is the string landscape. Each geometry for the compactified dimensions implies a different set of ... 13:44: ... principle the standard model lives somewhere in the string landscape, but without knowing the geometry of the extra dimensions, this can't be ... 10:31: ... a string conference in '95, Witten showed that the disparate string theories were all just different perspectives, different limits or special cases ... 14:00: Essentially all string theories require supersymmetry in order to work. 14:16: But string theories are still rightly concerned. Their elegant theory which was converging so beautifully has stalled. 14:00: Essentially all string theories require supersymmetry in order to work. 14:55: So perhaps string theorists should also stick to their guns. 00:13: String theory is certainly beautiful in the eyes of many physicists, but is it beautiful enough to pursue even if it's wrong? 01:03: Could this also be the case with string theory? 01:06: ... the very particular case of a quantum string, which is part of what got string theory going in the first ... 01:18: We talked about this in detail in our episode on why string theory is right. 01:23: Which itself was a sequel to our primer on the basics of string theory. 01:27: In those episodes, we saw some of the remarkable ways that string theory promised to converge on a theory of everything. 01:35: ... under one umbrella, and there's also the convergence of many versions of string theory into a single picture with a very specific number of extra dimensions. ... 01:55: ... of this promise of being so right do more and more physicists think that string theory is after all either woefully incomplete or just plain ... 02:07: Modern string theory is the convergence of many beautiful ideas in physics, each of which feel right in their own way. 02:14: ... see where string theory ultimately fails, we need to rewind to look at some of these a bit ... 04:57: These may have seemed like fatal flaws, but we can thank this wrongness for the later development of string theory. 05:16: String theory is just the most famous. 05:18: So, start with Kaluza-Klein, add vibrating strings and exactly the right extra special dimensions, and you have string theory. 05:40: It also introduces fermions to the boson only version of string theory to give super string theory. 06:03: Superstring started out with incredible promise, and so there was a proliferation of different versions of super string theory. 07:12: These dualities reveal that certain classes of string theory were actually the different ways of expressing exactly the same theory. 07:20: Perhaps there was a glimmer of hope for these divergent versions of string theory after all. 09:19: ... sounds weird but this may just have saved string theory. I just described a type of duality, in this case t-duality, short for ... 09:48: T-dualities prove that some of these different versions of string theory are actually different expressions of the same theory. 09:54: The other main type of duality in string theory is s-duality, strong-weak duality. 10:18: S-duality provided the final linchpin that demonstrated that the five different types of string theory were all manifestations of the same theory. 10:51: ... that it adds a single extra dimension, to connect all of the five super string theory types via ... 11:41: See, in parallel to the development of super string theory, other physicists have been working on super gravity. 11:49: ... Super gravity should be the low energy, large-scale limit to super string theory. So it was incredibly exciting that string theory appeared to have an 11 ... 12:14: ... with each other and with super gravity restored the sense of beauty to string theory. It appeared to be on the track to rightness once again, so So where did ... 15:00: ... wrong or incomplete as current string theory may be, it may also be the inevitable early step as we seek an even more ... 15:14: ... the physics required to understand string theory is tough thankfully there are online tools that can help like brilliance ... 11:49: ... limit to super string theory. So it was incredibly exciting that string theory appeared to have an 11 dimensional version, M-theory, to correspond to everyone's ... 01:27: In those episodes, we saw some of the remarkable ways that string theory promised to converge on a theory of everything. 10:51: ... that it adds a single extra dimension, to connect all of the five super string theory types via ... 02:14: ... see where string theory ultimately fails, we need to rewind to look at some of these a bit closer, to start ... 08:01: ... number of times a string winds around this compactified dimension is called its winding number. The ... 05:07: For example, adding more compact dimensions of various shapes and, of course, strings. 05:18: So, start with Kaluza-Klein, add vibrating strings and exactly the right extra special dimensions, and you have string theory. 06:20: Five different approaches to getting all of the desired particles out of the basic premise of strings wiggling in ten dimensions. 06:32: What differs is the detailed geometries and symmetries of those spaces, and the way strings vibrate within them. 07:50: Our tiny quantum strings can roam that small dimension. 08:17: These strings are vibrating with standing waves like guitar strings, and their energy also depends on the frequency of that vibration. 09:59: In this case it's a duality between strongly versus weakly interacting strings. This seems even more contradictory, but it's incredibly powerful. 12:53: The behavior of strings in these hyper dimensional surfaces is only understood in idealized cases. 13:08: ... dimensions implies a different set of porperties for vibrating strings, and so a different family of particles and different laws of physics to ... 06:32: What differs is the detailed geometries and symmetries of those spaces, and the way strings vibrate within them. 06:20: Five different approaches to getting all of the desired particles out of the basic premise of strings wiggling in ten dimensions.
	2018-12-12: Quantum Physics in a Mirror Universe 00:02: ... to seem heavily and yeah we'll be covering that after we do why string theory is wrong because you guys haven't stopped complaining that it ...
	2018-11-21: 'Oumuamua Is Not Aliens 15:28: Well, actually, modern string theory relies on supersymmetry so it's already included. 15:37: Actually, the name string theory originally applied to what we call bosonic string theory. 15:53: And these days some form of superstring theory is implied when people talk about string theory. 15:28: Well, actually, modern string theory relies on supersymmetry so it's already included. 15:37: Actually, the name string theory originally applied to what we call bosonic string theory. 15:53: And these days some form of superstring theory is implied when people talk about string theory. 15:37: Actually, the name string theory originally applied to what we call bosonic string theory. 15:28: Well, actually, modern string theory relies on supersymmetry so it's already included.
	2018-11-14: Supersymmetric Particle Found? 02:08: It's a key feature in some grand unified theories as well as modern string theory, leveling it up to superstring theory. 12:33: ... below to subscribe to "Two Cents." Last week, we talked about why string theory is so compelling to so many ... 12:51: Many of you have some interestingly passionate hate for string theory on the grounds that it's so far proved unfalsifiable. 13:04: String theory may be wrong, but it's not testable due to the limits of current facilities. 13:25: The thing that makes string theory less sciencey is that its modern version, M-theory, is not particularly well-defined. 13:39: String theory is not precise enough yet to be confirmed wrong, which means it might be right or not. 14:17: To quote, "I thought one of the fundamental properties of the strings was that the maths only works if they are one dimensional. 14:24: So how can you get world sheets?" Yes, it is a pain keeping the number of dimensions straight in string theory. 14:32: ... dimension of space and one of time, this is the shape traced out by a string moving through ... 14:47: So yeah, the math of string theory only works for 1D objects because these trace 2D world sheets. 15:32: But this has no bearing on the compactified extra dimensions of string theory. 16:06: And to end on a funny, Dash to the Max points out that string theory is literally like playing a sad song on the world's smallest violin. 16:16: And if it proves wrong in the end, at least we have the perfect instrument for a requiem to string theory. 14:32: ... dimension of space and one of time, this is the shape traced out by a string moving through ... 02:08: It's a key feature in some grand unified theories as well as modern string theory, leveling it up to superstring theory. 12:33: ... below to subscribe to "Two Cents." Last week, we talked about why string theory is so compelling to so many ... 12:51: Many of you have some interestingly passionate hate for string theory on the grounds that it's so far proved unfalsifiable. 13:04: String theory may be wrong, but it's not testable due to the limits of current facilities. 13:25: The thing that makes string theory less sciencey is that its modern version, M-theory, is not particularly well-defined. 13:39: String theory is not precise enough yet to be confirmed wrong, which means it might be right or not. 14:24: So how can you get world sheets?" Yes, it is a pain keeping the number of dimensions straight in string theory. 14:47: So yeah, the math of string theory only works for 1D objects because these trace 2D world sheets. 15:32: But this has no bearing on the compactified extra dimensions of string theory. 16:06: And to end on a funny, Dash to the Max points out that string theory is literally like playing a sad song on the world's smallest violin. 16:16: And if it proves wrong in the end, at least we have the perfect instrument for a requiem to string theory. 02:08: It's a key feature in some grand unified theories as well as modern string theory, leveling it up to superstring theory. 14:17: To quote, "I thought one of the fundamental properties of the strings was that the maths only works if they are one dimensional.
	2018-11-07: Why String Theory is Right 00:06: ... see string theory as the one great hope for a theory of everything that will unify ... 00:20: Others see string theory as a catastrophic dead end, one that has consumed a generation of geniuses with nothing to show for it. 00:29: So why are some of the most brilliant physicists of the past 30-plus years so sure that string theory is right? 00:37: [MUSIC PLAYING] Why has string theory been the obsession of a generation of theoretical physicists? 00:48: What exactly is so compelling about tiny vibrating strings? 00:59: ... short, the strings of string theory are literal strands and loops that vibrate with ... 01:14: And, by the way, these strings exist in six compact spatial dimensions on top of the familiar three. 01:21: In this episode, I'm going tell you why string theory is right, at least why so many of those geniuses think it is. 01:52: I also want to give you a teaser on why string theory is actually wrong. 02:01: The greatest criticism of string theory is that it's never made a testable prediction. 02:06: ... space of possible versions of string theory is so vast that nothing can be calculated with certainty, so ... 02:19: But string theorists might disagree. 02:22: They might say, maybe half jokingly, that string theory does make one great prediction. 02:41: But the fact is when you start to work out the math of string theory, gravity appears like magic. 02:47: You don't need to try to fight gravity into string theory. 02:50: ... fact, it will be difficult to remove it, and the quantum gravity of string theory is immune to the main difficulty in uniting general relativity ... 03:07: ... in a recent episode, but before we get to the nuts and bolts of how string theory predicts gravity, it's worth taking a moment to see how stringy ... 04:22: OK, let's switch to string theory where particles are not points. 04:32: When strings move on a spacetime diagram, they trace out sheets or columns. 04:37: In fact, you can think of a string not as a 1D surface but as a 2D sheet called a world sheet. 04:45: Now let's look at the interaction of two strings. 04:53: Even the most energetic interactions are smeared out over the string, so you avoid the danger of black hole creating infinities. 05:06: ... illustrate why quantum gravity isn't hopelessly broken in string theory, and that's a huge point in favor of string theory, but these ... 05:20: And this is the second point in string theory's favor. 05:22: ... see, it turns out that tiny vibrating quantum strings automatically reproduce the theory of general relativity and, in the ... 05:39: This stuff appears a little too naturally in the math of string theory to be a coincidence, or so a string theorist might tell you. 05:48: For some reason, vibrating strings are bizarrely well suited to quantization. 07:17: Quantizing the motion of strings also starts out ugly, but there are also some math tricks to make it work. 09:02: ... turns out that exploring a very different symmetry of string theory both makes it possible to quantize the theory and gives us a very ... 09:14: So, like I was saying, when we try to quantize string theory, of course it's a huge mess. 09:36: It says that changing the scale of space itself shouldn't affect the physics of strings. 10:25: That's on the 2D dimensional world sheet of a quantum string. 10:30: ... the 2D sheet traced out in spacetime by a vibrating 1D string has this symmetry that lets us redefine the scale on its surface however ... 10:41: ... quantum wave equation from the equations of motion, but only for 1D strings making a 2D world sheet, not for any other dimensional ... 10:57: This is part of what makes strings so compelling. 11:28: So, with our quantized equations of motion in hand, you can predict the quantum oscillations of our string. 11:44: ... you use string theory to write down the gravitational field in what we call the ... 11:57: ... get the right particles, including the graviton and the photon, out of string theory for a very specific number of spatial dimensions, nine to be ... 12:11: In fact, if string theory makes any predictions, it's the existence of exactly this number of extra dimensions. 12:18: And this is where string theory starts to look less attractive. 12:25: ... String theorists hypothesize that the extra dimensions are coiled on themselves ... 12:43: And that's just the first of many problems of string theory. 12:49: ... were lead to string theory by the elegance of the math and the fact that it appeared, at ... 12:58: ... convergence is also seen in the union of different string theories by M theory and in the discovery of AdS/CFT correspondence-- ... 13:26: Perhaps we're now overly distracted by the elegance of string theory. 12:58: ... convergence is also seen in the union of different string theories by M theory and in the discovery of AdS/CFT correspondence-- again, for ... 05:39: This stuff appears a little too naturally in the math of string theory to be a coincidence, or so a string theorist might tell you. 02:19: But string theorists might disagree. 12:25: ... String theorists hypothesize that the extra dimensions are coiled on themselves so they ... 00:06: ... see string theory as the one great hope for a theory of everything that will unify quantum ... 00:20: Others see string theory as a catastrophic dead end, one that has consumed a generation of geniuses with nothing to show for it. 00:29: So why are some of the most brilliant physicists of the past 30-plus years so sure that string theory is right? 00:37: [MUSIC PLAYING] Why has string theory been the obsession of a generation of theoretical physicists? 00:59: ... short, the strings of string theory are literal strands and loops that vibrate with standing waves simply by ... 01:21: In this episode, I'm going tell you why string theory is right, at least why so many of those geniuses think it is. 01:52: I also want to give you a teaser on why string theory is actually wrong. 02:01: The greatest criticism of string theory is that it's never made a testable prediction. 02:06: ... space of possible versions of string theory is so vast that nothing can be calculated with certainty, so string ... 02:22: They might say, maybe half jokingly, that string theory does make one great prediction. 02:41: But the fact is when you start to work out the math of string theory, gravity appears like magic. 02:47: You don't need to try to fight gravity into string theory. 02:50: ... fact, it will be difficult to remove it, and the quantum gravity of string theory is immune to the main difficulty in uniting general relativity with ... 03:07: ... in a recent episode, but before we get to the nuts and bolts of how string theory predicts gravity, it's worth taking a moment to see how stringy gravity ... 04:22: OK, let's switch to string theory where particles are not points. 05:06: ... illustrate why quantum gravity isn't hopelessly broken in string theory, and that's a huge point in favor of string theory, but these world ... 05:39: This stuff appears a little too naturally in the math of string theory to be a coincidence, or so a string theorist might tell you. 09:02: ... turns out that exploring a very different symmetry of string theory both makes it possible to quantize the theory and gives us a very ... 09:14: So, like I was saying, when we try to quantize string theory, of course it's a huge mess. 11:44: ... you use string theory to write down the gravitational field in what we call the low-energy ... 11:57: ... get the right particles, including the graviton and the photon, out of string theory for a very specific number of spatial dimensions, nine to be ... 12:11: In fact, if string theory makes any predictions, it's the existence of exactly this number of extra dimensions. 12:18: And this is where string theory starts to look less attractive. 12:43: And that's just the first of many problems of string theory. 12:49: ... were lead to string theory by the elegance of the math and the fact that it appeared, at least in ... 13:26: Perhaps we're now overly distracted by the elegance of string theory. 02:41: But the fact is when you start to work out the math of string theory, gravity appears like magic. 03:07: ... in a recent episode, but before we get to the nuts and bolts of how string theory predicts gravity, it's worth taking a moment to see how stringy gravity avoids ... 05:06: ... favor of string theory, but these world sheets will also help us see why string theory predicts gravity in the first ... 12:18: And this is where string theory starts to look less attractive. 05:20: And this is the second point in string theory's favor. 03:07: ... string theory predicts gravity, it's worth taking a moment to see how stringy gravity avoids the problem of black ... 00:48: What exactly is so compelling about tiny vibrating strings? 00:59: ... short, the strings of string theory are literal strands and loops that vibrate with ... 01:14: And, by the way, these strings exist in six compact spatial dimensions on top of the familiar three. 04:32: When strings move on a spacetime diagram, they trace out sheets or columns. 04:45: Now let's look at the interaction of two strings. 05:22: ... see, it turns out that tiny vibrating quantum strings automatically reproduce the theory of general relativity and, in the ... 05:48: For some reason, vibrating strings are bizarrely well suited to quantization. 07:17: Quantizing the motion of strings also starts out ugly, but there are also some math tricks to make it work. 09:36: It says that changing the scale of space itself shouldn't affect the physics of strings. 10:41: ... quantum wave equation from the equations of motion, but only for 1D strings making a 2D world sheet, not for any other dimensional ... 10:57: This is part of what makes strings so compelling. 05:22: ... see, it turns out that tiny vibrating quantum strings automatically reproduce the theory of general relativity and, in the same mechanism, ... 01:14: And, by the way, these strings exist in six compact spatial dimensions on top of the familiar three. 10:41: ... quantum wave equation from the equations of motion, but only for 1D strings making a 2D world sheet, not for any other dimensional ... 00:53: In our last string-theory episode, I talked about what these things really are and covered some history. 03:07: ... string theory predicts gravity, it's worth taking a moment to see how stringy gravity avoids the problem of black ...
	2018-10-25: Will We Ever Find Alien Life? 13:18: Last week we dipped our toes into string theory. 13:38: Add it to string theory and you get superstring theory. 13:54: ... response to me saying that string theory has only one tunable parameter, Michael Murphy sarcastically ... 14:04: ... he's referring to the number of calibrial manifolds that string theorists need to search through to find the geometry of our universe's ... 14:30: Now, some string theorists would say that there are zero free parameters. 14:43: Korbus Barkly and some others ask whether, if string theory makes no testable predictions, shouldn't it be just called string hypothesis? 16:20: Does not the idea of "shut up and calculate" and "we don't care what strings are made of" sound a lot like the flaws that science finds in religion? 17:25: He was struck by the potential of multi-dimensional Pringles to unify string theory. 14:43: Korbus Barkly and some others ask whether, if string theory makes no testable predictions, shouldn't it be just called string hypothesis? 14:04: ... he's referring to the number of calibrial manifolds that string theorists need to search through to find the geometry of our universe's extra ... 14:30: Now, some string theorists would say that there are zero free parameters. 13:18: Last week we dipped our toes into string theory. 13:38: Add it to string theory and you get superstring theory. 13:54: ... response to me saying that string theory has only one tunable parameter, Michael Murphy sarcastically points out ... 14:43: Korbus Barkly and some others ask whether, if string theory makes no testable predictions, shouldn't it be just called string hypothesis? 17:25: He was struck by the potential of multi-dimensional Pringles to unify string theory. 08:46: ... Anchordoqui and collaborators found a less stringent limit on this likelihood by assuming that a lot of life gets wiped out ... 16:20: Does not the idea of "shut up and calculate" and "we don't care what strings are made of" sound a lot like the flaws that science finds in religion?
	2018-10-18: What are the Strings in String Theory? 00:07: You may have heard the usual pop psy description of string theory. 00:10: There are these tiny vibrating strings, and that's where all the force's particles, including gravity, in the entire universe come from. 00:18: This raises more questions than it answers, like why strings? 01:20: That would be a theory of everything, and this is the great hope of string theory. 01:26: In the following episodes, we're going to explore the gory details of string theory. 01:32: But today it's String Theory 101. 01:38: I mean, why tiny vibrating strings versus literally any other tiny vibrating anything? 01:45: What exactly are the strings of string theory? 01:48: First let's do a quick primer on the origins of string theory. 02:09: ... suggested that the quarks in mesons are connected by-- you guessed it-- strings. ... 02:23: In this case, the strings are stretched out tubes of strong nuclear force, vibrating elastic bands made of gluons. 02:32: A lot of work went into figuring out a quantum theory for the strong interaction based on the physics of strings. 02:46: ... of the reasons this strong force version of string theory got stuck is that it predicted the existence of unexpected and ... 03:16: ... the type of particle produced by this little investigation into hadronic strings except that there's no way anything like the graviton should appear in ... 03:51: In fact, what if all force-carrying particles result from oscillations in tiny strings? 03:58: ... we needed was to make the strings a bit smaller, like 20 orders of magnitude smaller, shrinking from the ... 04:20: This was so-called Bosonic string theory. 04:31: If wiggly strings can explain force-carrying bosons, why not also the fermions that comprise matter? 05:22: Let's talk strings. 05:24: So wiggly strings could explain the whole universe. 05:29: To understand quantum strings, first we need to look at regular strings. 05:35: The key is that strings can carry waves. 05:38: And if the string has ends or is tied in a loop, then a wave will end up overlapping with itself. 05:57: Constructive interference only happens if the wavelength of the wave fits a neat number of times along the length of the string. 06:14: The result is that for a given string, only certain frequencies corresponding to certain energies are possible. 06:22: These resonant frequencies depend on the length of the string, also its tension, which defines wave velocity and so relates frequency to wavelength. 06:31: For example, this leads to the specific frequencies of vibration on a guitar string. 06:45: String theorists weren't the first to notice this. 06:57: But quantum strings are much more ambitious than boring electron orbits. 07:10: Particle mass just comes from the length of the string and its tension. 07:17: String length defines mass, but also defines which complex vibrational modes are possible. 07:29: So this is the great promise of string theory. 07:32: ... defining a single parameter, the string tension, or equivalently, string length scale, all of the possible ... 08:05: The strings are real physical strands, and the waves are wiggles in actual space. 08:36: Most string theorists are more interested in what strings do, not what they're made of. 08:51: These last properties are important because it gives a mechanism for the particles of string theory to interact and to decay into other particles. 09:00: This picture of strings coming together jointly and splitting apart is a huge strength of the theory. 09:31: String theory fixes this because the graviton is a loop, not a point particle. 09:37: Its interactions are smeared around that string, handily avoiding the explosion of mathematical infinities you get below the Planck length. 09:45: All this stuff sounds great, and by the way, doesn't work for any other geometrical structure other than a 1-D string. 09:54: So vibrating guitar strings, yes. 10:01: ... the strings themselves are 1-D, but to even start to produce the properties of known ... 10:41: But this sort of thing doesn't deter string theorists. 11:16: Very tiny objects like quantum strings could explore that extra dimension, and importantly, oscillate in it. 11:30: Three large dimensions of space and six tiny Pac-Man dimensions that only strings experience. 11:37: Voila, string theory is saved. 11:54: ... theory unites different string theories because it demonstrates some philosophically fascinating ... 12:13: The exact behavior of strings depends on the shape of their compact dimensions. 12:19: In fact, the single free parameter in string theory becomes the configuration of the extra dimensions. 12:25: Find the right location in this string landscape, and you perfectly describe the universe. 12:43: Right now string theory appears to be at an impasse. 12:53: Tuning that string landscape to match our universe is daunting and perhaps impossible. 13:08: In coming episodes, we'll look deeper into both the successes, the failures, and the profound weirdnesses of string theory. 09:37: Its interactions are smeared around that string, handily avoiding the explosion of mathematical infinities you get below the Planck length. 12:25: Find the right location in this string landscape, and you perfectly describe the universe. 12:53: Tuning that string landscape to match our universe is daunting and perhaps impossible. 07:17: String length defines mass, but also defines which complex vibrational modes are possible. 07:32: ... defining a single parameter, the string tension, or equivalently, string length scale, all of the possible particles should be automatically ... 07:17: String length defines mass, but also defines which complex vibrational modes are possible. 07:32: ... defining a single parameter, the string tension, or equivalently, string length scale, all of the possible particles should be automatically ... 11:54: ... theory unites different string theories because it demonstrates some philosophically fascinating dualities ... 06:45: String theorists weren't the first to notice this. 08:36: Most string theorists are more interested in what strings do, not what they're made of. 10:41: But this sort of thing doesn't deter string theorists. 00:07: You may have heard the usual pop psy description of string theory. 01:20: That would be a theory of everything, and this is the great hope of string theory. 01:26: In the following episodes, we're going to explore the gory details of string theory. 01:32: But today it's String Theory 101. 01:45: What exactly are the strings of string theory? 01:48: First let's do a quick primer on the origins of string theory. 02:46: ... of the reasons this strong force version of string theory got stuck is that it predicted the existence of unexpected and unwanted ... 04:20: This was so-called Bosonic string theory. 07:29: So this is the great promise of string theory. 08:51: These last properties are important because it gives a mechanism for the particles of string theory to interact and to decay into other particles. 09:31: String theory fixes this because the graviton is a loop, not a point particle. 11:37: Voila, string theory is saved. 12:19: In fact, the single free parameter in string theory becomes the configuration of the extra dimensions. 12:43: Right now string theory appears to be at an impasse. 13:08: In coming episodes, we'll look deeper into both the successes, the failures, and the profound weirdnesses of string theory. 01:32: But today it's String Theory 101. 12:43: Right now string theory appears to be at an impasse. 09:31: String theory fixes this because the graviton is a loop, not a point particle. 13:17: And you can decide for yourself whether you accept the fundamental stringy nature of space time. 00:10: There are these tiny vibrating strings, and that's where all the force's particles, including gravity, in the entire universe come from. 00:18: This raises more questions than it answers, like why strings? 01:38: I mean, why tiny vibrating strings versus literally any other tiny vibrating anything? 01:45: What exactly are the strings of string theory? 02:09: ... suggested that the quarks in mesons are connected by-- you guessed it-- strings. ... 02:23: In this case, the strings are stretched out tubes of strong nuclear force, vibrating elastic bands made of gluons. 02:32: A lot of work went into figuring out a quantum theory for the strong interaction based on the physics of strings. 02:46: ... of unexpected and unwanted vibrational modes in the gluon field of these strings. ... 03:16: ... the type of particle produced by this little investigation into hadronic strings except that there's no way anything like the graviton should appear in ... 03:51: In fact, what if all force-carrying particles result from oscillations in tiny strings? 03:58: ... we needed was to make the strings a bit smaller, like 20 orders of magnitude smaller, shrinking from the ... 04:31: If wiggly strings can explain force-carrying bosons, why not also the fermions that comprise matter? 05:22: Let's talk strings. 05:24: So wiggly strings could explain the whole universe. 05:29: To understand quantum strings, first we need to look at regular strings. 05:35: The key is that strings can carry waves. 06:57: But quantum strings are much more ambitious than boring electron orbits. 08:05: The strings are real physical strands, and the waves are wiggles in actual space. 08:36: Most string theorists are more interested in what strings do, not what they're made of. 09:00: This picture of strings coming together jointly and splitting apart is a huge strength of the theory. 09:54: So vibrating guitar strings, yes. 10:01: ... the strings themselves are 1-D, but to even start to produce the properties of known ... 11:16: Very tiny objects like quantum strings could explore that extra dimension, and importantly, oscillate in it. 11:30: Three large dimensions of space and six tiny Pac-Man dimensions that only strings experience. 12:13: The exact behavior of strings depends on the shape of their compact dimensions. 09:00: This picture of strings coming together jointly and splitting apart is a huge strength of the theory. 12:13: The exact behavior of strings depends on the shape of their compact dimensions. 11:30: Three large dimensions of space and six tiny Pac-Man dimensions that only strings experience. 01:38: I mean, why tiny vibrating strings versus literally any other tiny vibrating anything? 13:17: And you can decide for yourself whether you accept the fundamental stringy nature of space time.
	2018-10-03: How to Detect Extra Dimensions 06:15: They're used in string theory, where they typically have a large number of dimensions. 06:20: But in string theory, all but three spatial dimensions of the brane are inaccessible. 11:02: So string theorists are OK for now. 13:02: And string theories are an example. 11:02: So string theorists are OK for now. 06:15: They're used in string theory, where they typically have a large number of dimensions. 06:20: But in string theory, all but three spatial dimensions of the brane are inaccessible.
	2018-09-20: Quantum Gravity and the Hardest Problem in Physics 12:08: That's exactly what string theory seeks to do.
	2018-09-05: The Black Hole Entropy Enigma 11:24: You just need to add a little bit of string theory. 11:34: It might also be true, and obviously we'll be back before too long to talk about string theory and the holographic nature of spacetime. 11:24: You just need to add a little bit of string theory. 11:34: It might also be true, and obviously we'll be back before too long to talk about string theory and the holographic nature of spacetime.
	2018-06-20: The Black Hole Information Paradox 09:39: Leonard Susskind formalized this idea in the context of string theory in what we now know as the holographic principle. 11:22: ... ideas about the nature of information and entropy, exploded the field of string theory, and hinted at the possible holographic nature of ... 09:39: Leonard Susskind formalized this idea in the context of string theory in what we now know as the holographic principle. 11:22: ... ideas about the nature of information and entropy, exploded the field of string theory, and hinted at the possible holographic nature of ...
	2018-04-18: Using Stars to See Gravitational Waves 05:00: ... in which binary supermassive black holes were common, or from cosmic strings, if they ...
	2018-03-15: Hawking Radiation 02:55: They can oscillate with different frequencies, much like the many possible vibrational modes on a guitar string. 03:01: A particle is like a note on the string. 03:32: One way that quantum fields are very different to guitar strings is they can have both positive and negative frequencies.
	2017-10-25: The Missing Mass Mystery 13:17: Maybe we'll at least get some evidence for the string theory or something.
	2017-10-19: The Nature of Nothing 08:51: ... the same way that an organ pipe or a guitar string of a particular length only resonates with waves of certain frequencies, ...
	2017-09-13: Neutron Stars Collide in New LIGO Signal? 15:42: And Hot Fuzz is obviously a reference to black hole singularities in string theory.
	2017-07-12: Solving the Impossible in Quantum Field Theory 04:09: ... equation you string together from this one diagram represents all of the ways that two ...
	2017-07-07: Feynman's Infinite Quantum Paths 15:00: A few of you asked whether quantum field theory and string theory are the same thing. 15:16: String theory states that all particles are different vibrational modes in one-dimensional objects called strings. 15:30: ... with stunning success and is the foundation of the standard model, string theory is untested and may have nothing to do with ... 15:00: A few of you asked whether quantum field theory and string theory are the same thing. 15:16: String theory states that all particles are different vibrational modes in one-dimensional objects called strings. 15:30: ... with stunning success and is the foundation of the standard model, string theory is untested and may have nothing to do with ... 15:16: String theory states that all particles are different vibrational modes in one-dimensional objects called strings.
	2017-06-28: The First Quantum Field Theory 02:03: Anyone who's ever strummed or shredded knows that a stretched string vibrates with a certain frequency when plucked. 02:22: ... any point in time, every point on a vibrating string is displaced by some distance from its relaxed or equilibrium position, ... 02:38: Guitar strings are one-dimensional, but we can expand the analogy to any number of dimensions. 03:45: And let's go back to the string. 03:47: If this were a quantum mechanical guitar string, then there'd be a minimum amplitude for the vibration that depended on its frequency. 04:26: Everywhere in the universe, that value is usually zero, but just like the string or the air density field, it could oscillate. 02:22: ... or equilibrium position, and that displacement changes over time as the string oscillates back and ... 02:03: Anyone who's ever strummed or shredded knows that a stretched string vibrates with a certain frequency when plucked. 02:38: Guitar strings are one-dimensional, but we can expand the analogy to any number of dimensions.
	2017-06-07: Supervoids vs Colliding Universes! 09:30: And it could happen frequently or rarely, depending on the completely unknown details of the string theory parameter space.
	2017-03-15: Time Crystals! 04:28: So you prepare a string of ions where the line spins.
	2017-02-02: The Geometry of Causality 05:15: ... from my stationary point of view, I define my x-axis as a long string of spacetime events at different distances, but that all occur ... 12:07: ... out of the mathematical singularity at the center of black holes is with string theory, which proposes that particles that we see in regular 4D ... 12:22: One idea is that the inside of an event horizon is composed of a ball of raw strings, a so-called fuzzball, and that no infinite density exists. 12:07: ... out of the mathematical singularity at the center of black holes is with string theory, which proposes that particles that we see in regular 4D spacetime result ... 12:22: One idea is that the inside of an event horizon is composed of a ball of raw strings, a so-called fuzzball, and that no infinite density exists.
	2016-11-16: Strange Stars 13:09: ... go through the black hole information paradox, Hawking radiation, some string theory, the holographic principle, other ...
	2016-10-12: Black Holes from the Dawn of Time 03:21: For example, the collapse of cosmic string moves and the collision of bubble universes?
	2016-06-01: Is Quantum Tunneling Faster than Light? 10:15: Throw in some string theory and black holes and a really unique writing style and it's a very insightful Pop Sci book.
	2016-03-02: What’s Wrong With the Big Bang Theory? 04:31: ... together and what some of the resolutions might be-- [CLEARS THROAT] string theory-- another ...
	2015-12-16: The Higgs Mechanism Explained 01:32: But now, add some energy to that field at a particular spot, and it's like plucking a guitar string.
	2015-09-23: Does Dark Matter BREAK Physics? 06:58: Sinking down into the depths of quantum field and string theory, you can find all sorts of strange fish, WIMPs, axions, neutralinos.
	2015-08-19: Do Events Inside Black Holes Happen? 00:24: That means no Hawking radiation, no string theory, and no quantum anything-- baby steps.
	2015-07-29: General Relativity & Curved Spacetime Explained! 08:32: ... even when people are referring to relativity or string theory or whatever, it's just a lot easier to say the word gravity than ...
	2015-06-17: How to Signal Aliens 09:13: ... has a balloon in it filled with helium that's attached to the floor by a string and I simultaneously drop the van off a cliff and cut the string ...
	2015-06-10: What Happens to a Helium Balloon in Freefall? 00:26: Now, in that balloon video, there's a helium-filled balloon attached by a string to the floor of a minivan. 00:39: And at the same moment that I let go, I want to cut the string that holds the helium balloon to the floor.
	2015-06-03: Is Gravity An Illusion? 04:51: That is the new vertical and the pendulum string and the balloon string are just aligning with the vertical the way they always do.

75 result(s) shown.

Help · About · Index