The Battle for REALITY: String Theory vs Quantum Field Theory
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- čas přidán 20. 05. 2024
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REFERENCES
Quantum Field Theory: • Quantum Fields: The Mo...
String theory and loop quantum gravity: • Quantum Fields: The Mo...
Equations of the Standard Model: • The STANDARD MODEL: A ...
Quantum Chromodynamics (QCD): • The STANDARD MODEL: A ...
Quantum Gravity: • The STANDARD MODEL: A ...
Everything is a spring: • Everything, Yes, EVERY...
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CHAPTERS
0:00 Is String Theory Crazy?
2:19 Why am I in London?
3:28 String Theory and Quantum Field Theory differences
5:16 Why bother with String Theory?
6:52 Why does a graviton need to have no mass and spin 2
7:52 Why no Graviton in Quantum Field Theory?
8:47 String Theory solves quantization of gravity
11:20 Similarity and differences between QFT and String Theory
14:08 Why does String Theory need extra dimensions
15:01 Bottom line on String Theory
SUMMARY:
How is string theory related to quantum field theory? Quantum field theory (QFT) is a mathematical
framework that is close to a theory of everything. It describes nearly all particles and forces in the universe, and is consolidated into an overarching theory - the standard model of particle physics. But it is incomplete because it doesn't explain gravity. Enter string theory, which sounds crazy, mainly because it proposes a universe made of vibrating strings and with at least 10 dimensions! We only know of 4, the three spatial dimensions and time. It claims that at least 6 other dimensions are hidden from us. But it is popular because it has an answer explaining gravity in quantum mechanical terms.
String theory posits that the smallest building blocks of the universe are not point-like particles, but tiny, one-dimensional "strings" that vibrate at various frequencies and in different dimensions. Different combinations of frequency and dimensions describe all the different types of matter, forces and energy in the universe. There are several string theories, all related to a deeper overarching theory called M-theory.
Quantum field theory posits that all particles are excitations in fields that span the entire universe, and that forces are due to the interaction of these particles mediated by other particles called bosons.
Both theories in principle can mathematically describe all particles and forces. But we know quantum field theory works. This is not the case for string theory, but we continue to bother with it is because it can model particle that looks identical to the graviton, the theorized missing boson particle that could quantize gravity.
String theory models a particle with zero mass and spin of 2, which would be a graviton. It needs to have no mass because gravity propagates at the speed of light and has an infinite range. Only a massless boson particle could have such properties. A spin 2 is required to model an exclusively attractive force which is what gravity is.
Quantum Field Theory can also describe gravitons - as excitations in a theoretical graviton field. But the problem with trying to quantize gravity in quantum field theory is renormalization. This is the procedure of making a theory valid to infinitesimally small lengths. When we try to do this, we get infinities in the equations. So quantizing gravity using QFT, doesn’t work.
Unlike QFT, String theory solves the issue of quantizing gravity. But the price we pay is that is that we have to contend with 6 to 7 extra dimensions. This is a problem because these dimensions have never been detected.
Scientists have come up with explanations about where the missing dimensions might be. One is compactification. It's like floss - from far away, it looks like a thin 1D line. But as you look at it more closely, we can see it is 3 dimensional.
Another solution to the missing dimensions is that there could be super dimensional membranes in a 4th dimension isolated from us. We would have to exist outside of our local brane to see these extra dimensions.
If we could detect these extra dimensions, It would be significant evidence indicating that string theory is likely a superior model of the universe, and that QFT is an approximation.
But there are some similarities between QFT and String theory. The amplitude in QFT corresponds to the number of particles, just like the amplitude of the vibrations in string theory also corresponds to the number of particles.
#stringtheory
#quantumfieldtheory
Why does String Theory need all these dimensions? because its mathematics does not work in 4 dimensions. It only works if we allow the strings to vibrate in at least 10 dimensions. Note that extra dimensions could also be theorized in quantum field theories, but we have not needed them to make the theory work. The math works fine as long we ignore gravity. - Věda a technologie
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I remember when this channel had 530 subscribers that's when I subbed this channel had grown more than any other channel I have seen it's unreal 😮
String theory - if you need 10 dimensions to make the math work, it is right off the bat delusional as Penrose said.
Quantum field theory - if you need infinities to make predictions right, it's more delusional than string theory.
Maybe the “Tube Hypothesis” could further string theory and possibly quantum field theory?
- tube hypothesis proposes that the fundamental strings in string theory are tubes (possibly two-dimensional) that facilitate vibration, by channeling the flow of spacetime.
What are the particles that make a quantum harmonic oscillator.
It was a fun way to incorporate NordVPN into your science!
I'm absolutely sure we will find the other missing dimensions in the same place my dryer loses my socks.
Check your local paper, or online, for the next Single Sock Symposium (SX3) in your area. The best place to find that matching single sock you've been looking for that you lost through the dryer wormhole.
Your socks are in superposition, waiting to be measured.
@@alfadog67 then they must also be entangled because I'm missing whole pairs.
@martinblank-th2kx does that mean my socks disappeared at light speed?
Since your dryer lives in a symmetrical spacetime-system (see Noether theorem), eradication of your socks would violate conservation of energy (aka mass). There are three things, that hold in symmetrical systems - otherwise our universe would collapse: i) conservation of energy, ii) conservation of momentum, iii) Pauli's exclusion principle. Every single known physical law obeys these basic principles.
but the idea that a graviton being a force carrier conflicts with the idea that gravity is not a force but a twisting of space-time.
@harper262 what you are saying is exactly the problem physicists are trying to resolve. General Relativity says gravity is warping of spacetime due to mass-energy. QFT says fundamental forces, of which gravity is one, is mediated through particles. We need a new theory to reconcile the two descriptions.
But QFT says nothing about gravity. That's the problem. Gravity isn't a force but can be described in terms of gauge fields. In QFT gauge fields correspond to force carriers and so gravity is assumed to be a force. However, there is no trivial way to quantize gravity and that's where the problem lies - providing a quantized field-theoretic description of gravity @@Johnny-bm7ry.
That’s not what the issue is.
You can write down a perfectly good theory of quantum gravity in 2 dimensions, so whatever intuitions we have about general relativity aren’t really a problem.
The problem is that quantized general relativity in 4 dimensions is nonrenormalizable. You need to include an infinite number of free parameters to get results that aren’t obviously unphysical infinities. This is a huge problem and physicists really don’t like it.
Does the earth still have gravity if one day suddenly stopped spinning around (Rotation) ??
@@NPC2358 yes. All it needs is mass.
The Nord VPN Placement was hilarious :D
Is this some kind of stock app joke Im too ReVanced to understand?
Great job on the commercial insertion!
@@drasiella it was one of arvin's smoothest segues
"warp!"
😂
Nerd VPN
Me watching not understanding any of this but really interested
SAMEE. I'm only a physics undergrad so I watched twice in a row trying to understand
Same here 😅 I watched it and understood approximately 14% of it.
Saving this video and coming back to it when I get a little older
Fizyka pozwala wznieść się wyższy poziom niezrozumienia 😁
That reminds me of a Brian Regan joke about string theory.
I see an arvin upload , i click real quick
6:51 this is my first time seeing a string theory equation
Don't worry, you haven't been missing much. String Theory has nothing to do with reality and everything to do with the University system collecting billions of dollars in tuition $$$ from physics students. I can't imagine how cognitively compromised I would have to be before I would agree to pay an institution that much $$$ for a degree in science fiction.
and it is not one, just a misleading complicated formula one of many one can write.
@@ika5666looks fine to me, it’s an amplitude of genus g written as a sum over moduli. standard.
@@kashu7691 I see it, but it is not the "string theory equation".
@@ika5666 i would say it is, perturbative string theory is entirely equivalent to the set of all its amplitudes
So cool! Thanks for the detailed explanation 😊
Ok. This is one of those videos I will need to watch a few more times if there is any hope for me to almost understand. Thanks for the rabbit hole, Arvin.🙂
The visualizations are very helpful
I remember taking calculus in college. We were assigned the problem of rotating the y=1/x function around the x-axis to form a cone. Then calculate both the volume and surface area of the cone from x=1 to infinity. The result was a cone with a finite volume, but an infinite surface area. In other words, you could fill it with paint, but couldn't paint the inside.
My point : Just because the math says something .... doesn't mean it reflects reality.
Math can reflect reality, as you say, to a very high degree. One might even say it's unreasonable effective at it. 😏
Just never try to work infinity into those equations. 😂
Until you define what you mean by 'Reality', you can't say whether math is an accurate description of it or not. If your definition of reality includes the role of the (human) observer, then you have to use math to describe consciousness....good luck with that ...
...and I thought before I stopped using my DDCs, like Blender to make computer graphics, that was hard... czcams.com/video/w0bnigQ17JE/video.html What's the point now that Sora and stuff like that does the same thing with a few prompts.
@@portugalforme1198 Whoa, whoa, whoa. The brightest mathematicians in the world held a conference to put Mathematics on a firm footing.
THEY FAILED. I know that ppl like Bertrand Russell was there along with Kurt Gödel* IIRC, etc., so until the machine intelligence informs us what the world is really, we are just less hairy talking apes, and I'm not joking.
So what reality are you talking about, bud?
_______________________________________________
* ...and not because of his "Incompleteness Proof," btw. Mathematics itself is flawed... Don't tell me that my adv degree in Applied Mathematics and Statistics doesn't make me an Au'thor'i'ty on the subject (read like it's from South Park).
Remember very few ppl know the logical fallacy of "Appeal to Authority," so I can get away with saying that.
well yueah, that's why nothing in nature can accurately be pointed to as being "Quantum" because quantum is ahuman agreed upon abstraction of natures true mechanics ;)
Thanks for the info
I have an idea on how to visualize string theory's extra dimensions. As it's been said that it's impossible for our brains to visualize extra dimensions, this can bypassed by the assertion that the extra dimensions are compactified, so the visualization can remain 3D. Each of the extra compactified dimensions can be visualized by giving an object extra visual properties but keeping their 3D location the same. Imagine a ball. You can visualize it moving through the first 4 dimensions by moving it around and watching it in motion. Then imagine a 5th dimension: moving through a color gradient from blue to red. So now you can move a ball through regular 4D space (its motion being the 4th dimension), and you can move it back and forth through the 5th by changing its color from red to blue or back. You can then add additional visual properties to represent further dimensions. Imagine a conversation between 2 particles: "Hey, I'm here where you told us to meet, at the exact coordinates and at the right time, but I don't see you", "Your x,y,z is correct, and I'm still here. However, you need to come bluer to me. You're too far away off in the red. Come bluer and you'll see me" "Oh ok, I see you now. I must've taken the wrong turn at purple". If you take away an object's innate visual description and give it to the coordinate system, you can represent another dimension by having it represent another dimension's gradient by making it be an arrow that can point in various directions, each direction representing a point on that dimension's gradient. Like an arrow on a speedometer pointing to numbers, it could be pointing at its representive coordinate for that dimension. So if the 6th dimension were represented by a fuel fage, those particles can extend their conversation: "let's go for a stroll. We can keep our x,y,z coordinates, stay in the blue, but we can take a stroll from full to empty and then back. 1 lap". Since motion in the extra dimensions doesn't affect the x,y,z coordinates, this should work, as it remains conistent with the 3D world, borrowing some of its attributes to represent motion in dimensions we can't see, the same way that worldlines on a spacetime diagram borrow the Y dimension to represent time.
U r the first one to have a similar idea as mine..
Honestly I don't like this..
I thought that was an original idea of mine which only I thought of.. Feeling odd to see someone with similar thought process..
My idea was just the same..
It's like we all are living in red 3D space with yellow and other colours 3D space overlaying ours.. .
Imagine we living inside a Rubik's cube with each face colour emitting that color light and we living in red 3D face..
All 6 sides emitting thier colour ..
They are the other dimensions we can't access coz we are not just colour blind in our eyes but colour blind in our bodies as a whole..
And some higher being who is not colour blind can see us all 6 coloured beings with his eyes...
Just like we can see video games character but they can't see us or know of us..
@@godspeed5428 I have also considered the possibility that qualities associated with sensory experience could be considered as dimensions and formalized mathematically. Though I hadn't considered it in nearly so much depth as OP. It would certainly jive with the idea that consciousness plays some role in physics.
Wow! I appreciate your knowledge 😮
@@godspeed5428 makes sense
@@ero- thanks
Arvin, the image I have is more like that extra dimensions are rather the properties of a given point in space-time. Meaning 4 for space and time; 2 for electromagnetism; 1 for temperature; 2 for the strong and weak force; etc. BTW: As gravity is not a force but a gradient of bend space-time, I don't think a Graviton is necessary.
Thanks for this video
Like always, brief, concise and to the point description of comparison between QFT and ST.. Request you to make similar video describing the comparison between QFT and LQG (Loop Quantum Gravity).
Excellent, Arvin.
A little late to the party but at 11:14
i like the birth date and date of death for each forefather of mathematics and science being exactly true to fact.
That's why I like arvinash
The argument consisting of saying that "all other forces considered fundamental have a quantum model therefore the force of gravity must also have a model at the quantum scale" is untenable. Let us imagine that we are underwater beings having arrived at the stage of civilization, we could also begin to postulate that the Archimedean thrust, which raises objects in the water according to their density, must be the result of a fondamental quantum interaction to discover. However, we know that it is an emerging force.
"Let us imagine that we are underwater beings having arrived at the stage of civilization, we could also begin to postulate that the Archimedean thrust, which raises objects in the water according to their density, must be the result of a fondamental quantum interaction to discover".
What a crock of sh*t! It's just flim-flam. Nonsense. It doesn't mean anything.
Get a book, and start reading, kiddo! Right now it's just pathetic, get educated.
I was literally blown away by the way of your explanation😮👏
String Hypothesis*
As doctor who knows absolutely nothing about physics, but loves to learn about it, this video was amazing!!! Keep it up!
Uniting quantum mechanics and relativity will only lead to more questions, it won't be the theory of everything we hoped for. A true theory of everything must be able to account for all of the fundamental constants of nature. If a theory can be used to derive the values of all fundamental constants of nature, then we will finally have the Theory of Everything.
Very, very interesting video! Thank you Arvin Ash! 👍👍👏
Nice explanation, easy to understand.
Mathematically algebra is the driving force for working of QFT i.e its evolution into geometrical realities/topology and it is in the geometry of spacetime that gravitation arise. Can these be reconciled for example by an in depth description of how algebra (i.e.arrangememt of numbers as matrices and their interactions) give rise to a force which drives differential geometry? Or how these two branches of maths are connected at a more fundamental level? Would much like a video from you on this or allied topics.
How about “Tube Hypothesis”
- tube hypothesis proposes that the fundamental strings in string theory are tubes (possibly two-dimensional) that facilitate vibration, by channeling the flow of spacetime.
🤨
Actually, String Theory is a type of Quantum Field Theory, it is a QFT of D scalar fields living on the 2D world-sheet of the string
Indeed. At many places "QFT" should be replaced with "Standard Model".
It also depicts a bit old fashioned idea of string theory being a TOE, while most papers nowadays on string theory are about holography in which string theory is used as an embedding and calculational tool. Nice animations, though 😋
No it isn't. Because unlike 4d QFT, the "2d QFT" isn't the same as the actual theory, it's a description of a particular thing inside the theory, in a particular limit.
@@annaclarafenyo8185 ST is NOT the Standard Model, but it IS a QFT. Standard Model =/= Quantum Field Theory. QFT is just a theory of fields living in some arbitrary space-time, and String Theory is precisely that, a theory of 26 (for bosonic) or 11 (for superstring) scalar fields (the string coordinate functions) living on the 2D world-sheet traced out by the string. Yes, this looks kinda artificial since the world-sheet should be a submanifold of the background space-time, but that's only in the Nambu-Goto picture. In the Polyakov-Susskind picture, the world-sheet is it's own entity, and the background geometry actually emerges from condensates of gravitons. So yes, String Theory is indeed a Quantum Field Theory, just not a 4D Standard Model theory.
@@MessedUpSystem No. It's not that. You can't describe the full string theory with those 10 scalars (NOT 11, it's never 11) any more than you can describe the standard model fully using 4 scalars on worldlines. This is a mistaken point of view, please don't fall into it.
The 'fields' of superstrings are best thought of in string field theory, or in holographic reconstruction, never as the coordinate fields. The coordinate fields are the analog of Feynman/Schwinger coordinates, they describe the path of the string, not the physical content of the theory..
@@annaclarafenyo8185 The excitations in the 2 dimensional conformal field theory which string theory is (a QFT) play the same role as the excitations in the 4 dimensional QFT we call the standard model. In the standard model you have quantum fields which have their own excitations, giving different particles falling in some representation of the Lorentz algebra. In string theory the fields are the internal degrees of freedom, i.e. the bosonic and the fermionic ones, and these excitations fall in different representations of the Lorentz algebra, which can be translated to particles in space time (one of the curious aspects of string theory: worldsheet excitations become spacetime particles, which is non-trivial!) Every representation has its own beta-function, which in a conformal field theory should vanish: this restriction gives you the equations of motion of the particles in space time.
You can go one step further on the quantization level and consider string field theory in which you can create and annihilate whole string apparently, but that's something I never studied.
I actually stopped watching another video just to click on this when I saw the notification.
Same 😂
Exploring theories, even when they eventually don't give us all answers, is never a waste. It enriches our knowledge and often points us in a new direction.
Great explanation 👏👏👏
I'm sad that Newton died 10 years before I was born, but I'm also sad that Einstein wasn't as far ahead of his time as I thought. But, maybe Nord allows for time travel too. lol
Are you saying you're 296 years old? :))
This proves that Einstein invented a time machine, went back to Newton's time, then brought Newton back with him to the 20th century. Unfortunately, Newton kept blathering away the whole trip back, so Einstein forgot to stop and kill baby Hitler.
GOOD, thank you for this explanations. I like the comparison 👍 And only crazy ideas leads to new knowledge, by falsifying or proving.
You are so good at this! Love your channel.
It is amazing how scientists like Arvin Ash can intellectually pop into the strange world of QFT/ ST and still be able to pop out back into reality translating their findings so that "normal" people "nearly" can understand!
He's just doing propaganda against string theory.
The Nord VPN grift/ad was genius placement lolol
QFT and the Standard Model are really great but it does seem like we still have a fundamental misunderstanding of the nature of reality. It could be that we'll never truly understand it, we'll just make better and better models which leads to more and more discoveries and eventual engineering concepts. That's probably the most exciting thing about physics; it's a never-ending pursuit towards understanding. There is always going to be something new.
Thanks!
Thanks so much!
String theorists just keep changing the target for all their models.
It's a bit theoretical and not always my speed but I want to say Arvin gives a kind accessable summation of the status quo. I think your a unique voice in the field and I like your rigorous introductions to these topics. I keep hearing how strings are dead in predictions so there's no experimental data. So maybe there's something here for me
The thing I always wonder is what gets the mattress vibrating in the first place?
In my case, it takes an alarm clock that can't be ignored.
Thanks Sir for the excellent explanation
Arvin, you're getting better and better. So happy for you. Thanks for the video 🙌🏿❤️
Great video and breakdown. Quantum Field Theory makes more sense to me. It's how I envision things. I don't like string theory because it describes a string in a singular point of space. I just don't think that's right. That being said, I'm not a physicist or mathematician and I like everyone have a lot of questions. There's no doubt we are missing a lot of the pieces of the puzzle. I think someone will have to come along and really throw a curveball idea to help us make some progress like Einstein did. There's a lot of problems:
1. Dark Energy - Expansion of the Universe caused by who knows what
2. Dark Matter - Massless gravitational phenomena holding galaxies together but we can't figure out what it is. Right, makes sense...
3. Quantum Gravity - How gravity works on the quantum level. My feeling with this is that if we proved that gravitational waves exist, doesn't that inherently prove there is a gravitational field? Sorry I'm a novice
4. Time and Space- I for one really struggle with time and space. What even is time? We describe it as a dimension, but to me it's less a dimension and more a law of change/entropy. The more space things occupy or warp, the slower time/entropy occurs. Weird dude.
5. A million other things we don't know....
Anyway, I have to get back to my life, its a funny world. Someone smarter than me will figure it out.
So basically we are not any closer
Like many other vids..but especially this one, learned and memorised some things very easily..was veeeery goodly explained!!
Half a century of failing to connect with experiment strongly suggests that this is not a fruitful research direction. Time to try some other ideas. I agree with Sabine Hossenfelder that it makes sense to focus on resolving known experimental anomalies and logical inconsistencies -- whether or not that ultimately ends up taking us back to something like string theory.
Actually watched the ad because the lead into it earned it
Thank you for new video, always a pleasure!
11:16 The timelines of Einstein and Newton are switched. I did a double take when I saw that Newton lived well into the 20th century 😂
11:16
@@andreybobzhenko1018Thank you for the correction
THANKS FOR THE VIDEO BROTHER 💙🙏💙🙏💙🙏💙🙏
Could you do a video analysing the relationship between Quantum Field Theory (QFT) and Loop Quantum Gravity?
Hi Arvin. I've heard gravity described as both a force and the natural result of spacetime curvature. Are these views consistent with one another?
Amazing information... Thanks Arvin🎉
String theory is pretty. But what has led to? What breakthroughs in physics has it brought? Is it just elegant maths? Is maths reality or just approximation?
Gravity is not a force from outside,not like others:
Gravity is the force from inside of you,your real love.
It could be the extra dimensions are levels of spirality (coiling) and levels of spirality within or upon other levels of spirality. And also the clockwise vs. counterclockwise chirality of the coiling. Wind a rubber band enough times between two hooks, and if the twisting doesn't break the rubber band you eventually start to see hypercoiling.
Excellent video my friend!
String Theories are Quantum Field Theories.
Just in standard model we use this Hilbert space with tetravectors.
We obtain points which form a distribution. It resembles our wavefunction.
Putting 2D objects there is cool because it allows more degrees of freedom to distribute energy... And the characteristic of modeling a particle which is a boson with a non repulsive counterpart.
Standard model is PARTICLE PHYSICS. Subatoic particles like quarks and bosons. QUANTUM physics is different, mostly studying how probability waves interact with echother.
Your videos are awesome & to the point to the main Subject...
kudos for using about four animations for the entire video
8:26 - Holograms can appear to move as Time allows everything to move - giving the perception of three dimensions.
"Limited physical significance" -- in other words, the generals haven't figured out how to use it to make a new weapon. That's probably a good thing.
This is underselling quantum field theory. Any local (with other modest constrains) quantum theory are equivalent to a quantum field theory at low energy. In this sense, quantum field theory would always describe reality at low energy. This idea is Wilson's renormalization. This is similar to no matter what smooth function (with other modest constrains) you have, its behavior at low energy (global minimum) would always be like a 2nd degree polynomial.
The 2nd degree polynomial would always describe such functions at low energy... similar to how quantum field theory would always describe such functions at low energy.
The version of quantum field theory we have (core theory or standard model + naive gravity) can in principle already explain all daily phenomenon like biological, neuro science (and anything that is not made from billions dollars particle accelerators which is the reference for low/high energy)
Hi @ArvinAsh. Does Roy Kerr’s work on black holes contradict general relativity? If I recall correctly, he says that singularities are not necessary in black holes
One is wrong, the other is not even wrong.
At 11:14 the dates indicated are changed
Actually, in the String Theory of the universe, these dates are correct. The strings pull you back and forth through time, like a yo-yo.
One question I have never seen answered in these videos about string theory. Why does gravity have to be quantized and part of a unified theory? Is there a reason for this other than it would be tidier?
An Oscar nomination for Arvin and his NordVPN act please :D
A theoretical framework based on "crazy" idea that supersedes string theory has been explored since 2000 by some physicists. Their theory, published in peer reviewed journals, is based on the concept 'Clifford space', a space of oriented areas/volumes associated with fundamental physical objects. The latter objects are assumed to be representable as branes living 4D spacetime. Instead of describing them in terms of infinite number of degrees of freedom, we describe them in terms of 16 degrees of freedom. For instance, a closed string (1-brane) can be fully described in terms of four embedding functions. Instead, it can be sampled by its center of mass and the oriented area enclosed by the string. The analogous can be done for 2-branes and 3-branes. So we arrive at the 16D Clifford space or C-space. This is just a sort of configuration space. A particular matter configuration can be represented in C-space as a point that traces a world line in C-space. Another type of matter configuration can be represented in C-space as a string that sweeps a world sheet in C-space. Such string in the 16D C-space, whose signature turns out to be (8,8), can be consistently quantized. The extra dimensions for the consistency of string theory are in C-space. The underlying space is 4D spacetime. In this theory, there is no need to add extra dimension to spacetime, and thus no need for their compactification. All the problems of the usual string theory, associated with compactification and similar, vanish.
Namely, there is a significant challenge in higher-dimensional theories, including string theory, regarding how to render the extra dimensions unobservable. A commonly employed approach involves assuming that the extra dimensions are compact and small. However, we can sidestep the necessity for compactification by postulating that spacetime is a subspace of a multidimensional configuration space-specifically, the space of possible matter configurations in 4D spacetime. Instead of formulating physics in spacetime, we can formulate physics in configuration space. In particular, as mentioned above, configuration space can be C-space.
A potential avenue in this direction was explored in my talk titled "Extending Physics to Clifford Space: Towards the Unification of Particles and Forces, Including Gravity." I delivered this talk as part of the lecture series "Octonions, Standard Model, and Unification," held from February 24 to December 15, 2023.
The video recordings of these lectures can be accessed at https:czcams.com/play/PLu4STGsfbix-_0BMOtpiH-_hOnBb2Xh5C.html. Specifically, the video recording of my lecture is available at czcams.com/video/lsYKz_uMb0c/video.html.
In the talk there is a section on how string theory can be consistently formulated in a target space with neutral signature (p,q) with p=q. In that setup, the higher dimensional target space is the 16D space, with signature (8,8), of the oriented areas/volumes associated with fundamental objects.
Was the field (web) there all along ?
Or does it appear as part of the physical world ?
String theory is probably correct. We just don't have equipment or knowledge to prove it. It's a shame b/c we will waste decades before coming back to it only to find out it's right. This always happens in physics.
I'm excited to see the Million subscribers 🎉🎉🎉🎉
Make a video on Russell's paradox and set theory.
Has anyone ever considered that space-time isn't "the background upon which quantum fields exist" but, that, in fact, quantum fields ARE what makes up space-time?
well it's my own personal thinking what if we have to change something in physics and in something else like how we perceive the virtual particles
What's truly unmeasurable is the amount of damage string theory did to modern physics over the decades.
I didn't see any damage. The only somewhat tangible "prediction" is supersymmetry and that will, most likely, be found anyway, whether string theory is the source or not.
Michio Kaku is out of control. . . .
Sean Carroll is covering up for this as well
Hear me out:
Strong, weak, and electromagnetic forces are three forces with spin 1 and possible repulsion.
Gravity is a force with spin 2 and only attracts.
We can move backwards and forwards in the three spatial dimensions, but only forwards in time.
So, gravity is just another effect of time (which we get from relatively anyway!) And we should really be looking for the chronon, not the graviton!
I'll take questions offline ;-)
From what I've heard in Susskind's lectures, String Theory must give QFT in its limit similarly to how quantum mechanics gives us classical mechanics in a limit. They do not oppose each other, ST just serves as a basis for QFT. Or as some other people formulate it, "ST is a QFT in such and such setting". I'm not familiar with details though, ST is way above my level.
@ArvinAsh
Could gravity in quantum field theory be thought of the disruption in symmetry when there’s a manifestation of a certain “particle” in a field forming its rest mass/energy like in the Higgs field?
Also, in a separate question. Do photons have a gravitational effect (including on each other)? Energy has a mass equivalence, however, photons are massless and their energy is “kinetic” since they have no rest mass E^2 = (pc)^2 + (m0c^2)^2. Does that mean that if photons do “produce gravity” that it is all from its “momentum related mass” that would be its kinetic energy equivalence?
Thank you 🙏🏽
In Einstein's equation energy and momentum create gravity, not just (rest) mass. Mass enters the equation as one kind of energy, via E=mc^2. But even without mass, with just energy and momentum, photons do influence spacetime curvature, yes.
Arvin, super way to introduce your sponsor hahhaa
I've got to make myself understand this!
Ok, kudos for the sneaky sponsor message, I'm not even mad.
love this
I can't help feeling that they just keep adding strange ideas and mathematics to make their theory work out in the end but being completely unrealistic.
Question: Why don't we consider mass itself as a consequence of the excitation of the gravitational field (space time)?
@ArvinAsh what do you think of Nassim Harramein's work? Is he's blowing hot air, or do you think he's on to something?
Hi Arvin. I know it's not related to this video as such but the spin function of particles made me think.
What would be the implications of a spinning universe before the big bang. After expansion would it still have spin/rotation? How would we know if we are still in a spinning expanding universe?
You would see new terms in general relativity, for one thing. The idea has been explored, but if you turn those terms on, then some really strange physics starts happening in the x-ray and gamma-ray region, where the coupling between torsion and the electromagnetic field becomes strong. This hasn't been observed, so it stands to reason that nature is torsion free.
I am thrilled to see you back the The Sciences Pages. Here's to you ARVIN.!!!
Takes a brave man to take on Feynman. Good effort but how many dimensions can be invented to square the numbers ?
Love it, hooray AA!
Didn't Einstein say gravity isn't a force but an acceleration due to warped spacetime. So it can't be quantized.
No Einstein did not say that. He considered his geometric explanation of gravity to be a "crutch." He believed there was a superior theory that would be more complete, and not cause singularities at the limits.
I like the compaction
To say that Quantum Field Theory is battling String Theory for describing reality is like saying Warren Buffet is battling the guy who sells get-rich-quick courses on CZcams over who has more money lol
From a philosophical point of view, it seems that there is a supergravity that transcends the entire physical framework
Do you have a video that talks more about why we need a graviton, i.e. a particle that mediates the "force" of gravity? My understanding is that gravity is an effect of spacetime curvature, so what does that have to do with a mediating particle?
In QFT every field is quantized and everything is described via particle creation and annihilation operators. All interactions between fields go via creation or annihilation of their quanta. When we apply this principle to Einstein's gravity field of spacetime curvature, it also becomes made of its quanta, we call them gravitons.
Dear Arvin, we enjoy all your videos, thank you so much for taking the time to educate us on these complex subjects.
QFT ~ 1s and 0s, most of the "important stuff" happens in 4 dimensions
ST ~ The physical silicon chip/gates - the effect is perceived in 4 dimensions, but only functions with more
The analogy of a CPU works well here - we see the resultant data at a high level, but we dont observe the electricity moving at the CPU clock speed, nor the behavior of the atoms at the processor gates. Nor could we with just a stock running Intel chip. The only way to "observe" the behavior within the gates is with additional tools looking at a running CPU. The only way entanglement could happen is if there is an interface for quantum interactions that we arent observing. One non-breaking way entanglement could work is if that interface isnt locked to just 4 seemingly linear dimensions. Its basically the notion that quantum mechanics isnt deterministic in 4 dimensions, but there is a frame of reference where it would be. Kinda more like a dog and their owner playing wackamole with a hot dog. The dog only sees which hole the hot dog comes out, but not the hand moving it. We dont see individual electrons in CPU gates, but the 1s and 0s make cute dog videos.
awesome explanation graphics and all. Thank you. Please, I want to ask: what it the problem with the idea at t=8:17 ? What is the problem with something like: ok, the fields exist in the "stage" provided by spacetime. Why can't the fields "just" exist in the continuous spacetime and that is it? the argument at t=13:46 of why one need to make gravity quantized seem kinda aesthetic and not technical. Thank you anyway, awesome class.
We want to know how quantum particles create that spacetime curvature. Particles can be in superposition of states / places, like electron somehow passing through two slits. When it does, which way space curves? Totally unclear without quantum description of gravity.