This is literally the best lecture you could ever watch on this subject. Not dumbed down, gives mathematical and technical details but not too technical to the point a layman can’t understand. Just brilliant.
Wow, I noticed those too, but I thought I might just have slipped into a different universe - or a different brane. Glad to have had you there with me.
As a layman you should really feel overwhelmed since it's not random letters put into words but real, rigorous descriptions and theories of the universe.
So when we compactify the extra dimensions, it seems like we're making an assumption. As if we're just trying to rationalize the results. Or is there some evidence to support it beyond conjecture? I'm considering another possibility. Which is that perhaps the only reason we experience 3 spacial dimensions and 1 temporal dimension is because we've evolved to only need these dimensions in order to compose and understanding out of the world around us. Similar to how even though we can only see visible light, we know that it's only a very narrow band of the much larger electromagnetic spectrum.
The motivation is that QFT is obviously incomplete or even wrong at some level. Thats why we need a different theory. Kaluza and Klein have shown how a compactification of additional dimensions can unify forces, which appaer seperated in lower dimensions. That was already in the 40s. Later, math and physics were finally unified again by Yang and Mills. They showed the world that any field is the curvature of a conncetion 1 form one a principal bundle with a lie group as structure grp. It turned out that any QFT can be described via bundle theory. Some might know them as gauge theories. Quantum gravity in 1 dimension is equal to a quantum field theory. In two dimensions it is called string theory. The great thing about the two dimensional case is the vanishing of any singularities of feynman graphs, which is very appealing to a physicist.
This was extremely detailed and deep. I'm out of my bachelor level physics curriculum for quite some years now so he did get a bit over my head on some aspects. It's amazing how far we've come in putting together these multi-dimensional models and in interpreting the results of these mathematical findings. Very exciting stuff and well presented.
maddie Sherouse funny kid.. do even know what a derivative an integral mean? i'm also a b.Sc but this was way over my head, the math and small scale of string theory is the main obstacle that make her useless..
You should know that i go out of my way to learn as much as i can about science and mathematics.I can infer that you didn't pay attention to the word almost.I am not a super child.I don't know everything.
+TaxTheFed: If you read his popular books, they will give you more background to fill in some of the gaps. Of course, one needs to know the mathematics in order to truly understand, but I find I can at least grasp the gist of what he's talking about.
Problem if the math doesent work out then just start adding untestible extra dimentions . The equivalent of if you dont know the answer then baffle them with bullsmitt
If string theory is shown to be dual of Q.M. How does that account for 'probabilities' and space of states being a vector space that leads to possibility of superposition ?
One of approximately 2,400 species of leaping insects (order Orthoptera) that are worldwide in distribution and known for the musical chirping of the male.
Interesting math and models but not a scientific theory. Why? If you can't design an experiment that can test your model then its not a scientific theory. Mathematical consistency is not enough. We don't have to prove Brian Greene wrong. In fact the burden is on Brian Greene to design experiments that can be performed to test string theory. This is how science works.
oWoudl live to see Brian Greene speak. When are you coming to D.C? I'm sure there's always a place at Politics and Prose. It'd be packed, and I'd be the first one there.
There will be always new kind of matter and that is difficult to predict in string theory because new kind of strings will always be created. Because matter is always a variable. Strings will behave differently. So possibly infinite.
what would be the implications of finding an imaginary Pi value for forces interacting considered the gravtiational constant and different masses with different distances?
Is on RU-vid the "full" lecture with B. Green available? At the end he cuts his lecture so not all was presented! I love to here the full story - great video!
It's not that they edited the lecture down; he ran out of time and didn't present the full lecture he had planned to give. Perhaps he gave the same lecture elsewhere and managed to get to that material; I don't know. Your best bet is to write to him at Columbia and ask for his lecture notes.
Consider what is E=MC2. TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). It is imperative to consider why and how it is that there is something instead of nothing ON BALANCE. WHAT IS GRAVITY is, ON BALANCE, an INTERACTION that cannot be shielded or blocked. Consider TIME AND time dilation ON BALANCE. Consider INSTANTaneity. Excellent. By Frank Martin DiMeglio
String theory: the most predictive theory... that has yet to make any predictions. What do we use to build accelerators and particle experiments that actually works in the real world? oh yea, the standard model of particle physics. String Theory has some major problems, and until it starts making useful predictions that we can base experiment off of, it's not a scientific theory, it is a hypothesis.
Yeah, Brian agrees with you. He has even commented several times that he would prefer not to use the word theory but that it has become part of the traditional name.
How did string theory get funding because what I have seen from debates with atheist they dont consider it science and how did they get access to school children
Black holes are like the invisible parts of the particles in the other side of a touch light. Edges of a torch light looks to have more galaxies spinning at the other side because light is facing the other side.
if -1/4F^uvFuv+i"Y"D"Y" assumes four dimensions gravital field symmetry and m is any value, C=^4 and g=c=1, the solution to the schroedinger equation is -4(ih-t)/2m delta square or "Y"^2 = "H"^2. what is a boson if E=ΩC^V?
The thing that bothers me about the boson is the fact that it does not rotate which makes me believe we are still looking for something that does not exist. Non rotational particles just does not make sense.
Dano _ I assume you're referring to the Higgs Boson, and the fact it doesn't have spin. Spin doesn't correspond to the particle rotating on its axis. It's is difficult to explain but it is just an intrinsic property of the particle similar to the idea of mass or charge. Why does a spin-0 particle make no sense to you? There are several (albeit composite) particles that have spin-0, it shouldn't be a huge shock that we have another particle with spin-0
E=ΩC^V energy is inertial to mass... could a boson be a magnetar energy state (protons, neutrons, quazars, and magnetars... they could be called magnetar stars)?
I wonder what he'd have to say about the idea that there is only one particle in all of creation that has no mass and therefore the ability to travel at infinite speed. This particle makes up all the matter in the universe by crossing its path. That's actually how ETs explain M-Theory.
8 лет назад
Wonder if Dark matter could be a force spiltted from gravity at the big bang or later when expansion stopt.
imagine that gravity itself is not defined by the planet, when we talk about earth, but a force in space., a gravitational field everywhere in space that reacts to mass simply by existing in space.. the earth exists in space and puts pressure on this field by existing there and in return., this field puts equal pressure back on the planet.. almost like a higgs field . a field existing everywhere in space but only reacts to mass, like the planets , while particles with little or no mass has no effect. then add in frame dragging and energy to boost the effects of gravity. curvature of space time seems incomplete...
You just (sort of) described Einstein's theory of general relativity, where gravity isn't a force but instead a distortion in spacetime caused by mass. It is incomplete simply because on a quantum level gravity as Einstein described it doesn't work in that way. Plus on a universal scale, gravity doesn't show to effect the expansion of the universe as much as the dark energy that's causing the universe to expand faster than the speed of light.
нефик хаять СМ.. 20 подстроечных параметров, нет гравитации, ой блин.. У суперстун там вобще 999 подстроек и можно чёрта лысого из неё вывести, который кста не пояснит почему он такой появился в 11 мерном пространстве.. не понравилась такая позиция Грина.. пусть об этом вещает когда М-теория начнёт считать кхд на решетках с 99.99999% погрешности струны хуже и СМ и ОТО по отдельности и не отвечают на вопрос откуда и с фига столько подстроек.. да, обьединяют гравитацию, но это явно не теория всего ПС извините за мой русский
kenny quintanilla Not in this case. String Theory really is more like what people think of the word theory, rather than say the theory of gravity and evolution, which are as you described.
Time to head off string theory- it does not predict and whilst I believe the Standard Model is not correct, it does currently predict results. Some results. Science is a process, and these theories are simply the current knowledge. How cool but do wish the scientists would note that they "think" and "believe at this time" and "to our best knowledge" when they talk about their theories.
problem with string theory is that the "strings" are too small to be measured in current equipment. We will need particle accelerators the size of the moon to maybe see these. I think strings are around plank lengths.
string theory is correct cause me and you and everything is the words of god as mentioned in quran and bible..words are kind of music and notes and this is our reality its huge symphony...the words are created by knocking on membrane above us at the edge of the universe the event horizon..there are 7 knockers or membranes and the words come dowon seven stages before they become our reality...its all mentioned in quran in details and the holographic principles is mentioned there in details tooo..
@Imjust Observing No String Theory ruined theoretical physics and the money junkies who've infested our institutions use String Theory to maintain their priveledge. Dark Matter has outted them and destroyed their SUSY bs.
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Christian Farina in what way is rigorous mathematics albeit without experimental validation worse than believing numbers have mystical, unexplainable power?
Precisely because they try to turn rigorous mathematics, which is something that works in an abstract setting, to physics, which is grounded and founded on experimental evidence.
Christian Farina No, you need rigorous mathematics to have a self consistent physical theory. That goes hand in hand and has done for centuries. Now the problem with String Theory and theoretical physics as a whole is that there is a huge gap between the energy scales accessible by particle accelerators and the energy scales needed to probe modern theories. This, I might add is not so much a problem with theoretical physics, more so it is merely a problem of engineering. However, just because the energy scales are inaccessible as of yet, does that mean we stop doing theoretical physics? No. String theory is an elegant theory in that in combines all fundamental forces including gravity into one framework. We have no other model that comes close. One could argue perhaps theorists should work closer to home and seek theories that are testable. In my opinion it's hubris, string theory promises so much as a theory that it is just too big an opportunity to miss. One thing that shouldn't be overlooked as Freeman Dyson once said; is that having a fully self consistent theory in itself is an achievement, but of course physicists will strive for better than just that. Even if string theory turns out to be wrong, the techniques and machinery used in the theory will be useful to theoretical physics for decades to come. Saying it is worse than numerology is borderline ignorance I'm sorry to say.
Mr. Malloy. I have no problem with string theorists as long as they don’t claim that "it is the only game in town". The facts are indisputable: There is no experimental evidence that string theory is a correct description of reality. String theory doesn’t provide a unique solution but instead tells us that there are millions of them and no way of knowing which one to pick. I personally think string theory is a beautiful theory and worth pursuing if you’re a mathematician because it actually helped us discover new things in math. The problem I have with them is that they basically hijacked our academia and they now have such a strong grip that I fear physics as we know it might be dead.
The sky is not falling, again, relax. And besides, if a theory is so general that it provides millions of solutions, then what is likely is some additional principle or intuition is needed to narrow things down to either find a smaller subset of possibilities or to rule out the theory entirely. I understand people's frustration that the second option feels impossible to do (ruling string theory out), but at least when it comes to the first option of narrowing down the possibilities, the fact that it's unclear what to do at this point is not a reason not to try. As for whether it's the only game in town, people are well within their right to work on alternative theories. Yes funding is an issue, but then it is the culture and historical basis for how funding and positions are awarded that is killing physics and innovation in general, it is not the fault of string theory or string theorists. I do however agree that it's ridiculous that people will assert that their theory is the correct theory without more evidence, this is after all unscientific. But some subset of scientists and academics in general have always been arrogant, so this is the point of reform that I would discuss: "do arrogance and existing funding structures, which are fundamentally unscientific, do more harm than good when it comes to advancing science?" But I would not say string theory is killing or has killed physics.
Not really fair. He is talking about particles smaller than quarks and fermions. I honestly think we will revisit this idea in a hundred years or so when the equipment to observe strings exist. The tech simply isn't there yet to peer at things smaller than quarks or gluons.
Physicists want proof for everything. All known laws of physics break down inside a black hole because we haven’t discovered the mathematics needed to prove anything. String theory is the opposite. Infinite calculations that have no proof
