The Trouble with Gravity: Why Can't Quantum Mechanics explain it?

[@rickpontificates3406]

Gravity always fascinated me because it's the only fundamental law that interacts with time. Unlike electromagnetism or the the strong and weak forces, we are living INSIDE gravity (spacetime), which might be why we can't properly study it, because we can't step away from it to analyze it objectively

[@lacommunautebienconnue349]

Everything interacts with time.

[@hyronvalkinson1749]

@@lacommunautebienconnue349 What they meant is that gravity is not time-invariant like the other forces. Sometimes it's called a fictitious force like centrifugal force - real and measurable, but only a helpful tool and nothing more.

[@lacommunautebienconnue349]

@@hyronvalkinson1749 Gravity isn’t a force.

[@hyronvalkinson1749]

@@lacommunautebienconnue349 If I shove you, that's a force. It's not a fundamental force and it's caused by other phenomenon entirely but it's still a force. You can still use Newtons to measure gravity

[@lacommunautebienconnue349]

@@hyronvalkinson1749 If it’s not the same definition then it’s not the same thing.

[@Riogrande1964]

This is by far the simplest and clearest explanation of this issue that I've seen or read, period. Excellent, easy-to-understand graphics aid comprehension. Great job.

[@ThomasJr]

There are many others. But your statement is accurate since you said "that I've seen". If you consider all the explanations, then this statement is no longer accurate.

[@uglystupidloser]

it's entertaining... but i do not understand.

[@replica1052]

(where gravity is shielding from cosmic radiation gravity can never exeed the speed of light )

[@marcinha1973]

@@ThomasJr Can you provide some links or what to search for the other explanations you have in mind?

[@ThomasJr]

@@marcinha1973 Do a search for quantum gravity and pick the videos with the most views, such as > 100K. I watched many wonderful videos and even better than this one. Especially from professor Leonard Susskind, Dr. Sabine Hossenfelder, Dr. Don Lincoln from Fermilab, and Dr. Matt O'dowd from PBS Space Time.

[@leighedwards]

Feynman was renowned for his ability to explain very difficult problems to others and so do you Arvin very well done.

[@alison4316]

Absolutely agree.

[@Cosmogenitor]

Arvin, you are absolutely my favorite science communicator. You don’t just make the explanations of the physics so clear, you also articulate the questions that demand more fundamental answers and the logic that gets us to new theories and solutions SO brilliantly. I learn so much from your videos, and the most valuable thing is how to *think* better. THANK YOU!

[@ArvinAsh]

Glad you like them!

[@SunDogGod]

Honestly! I watch other channels like pbs and they are not as good at making things simple and easy to understand

[@voidisyinyangvoidisyinyang885]

@@ArvinAsh You should read Professor Basil J. Hiley. He was the collaborator with David Bohm only Hiley has now relied on noncommutativity to explain relativistic quantum physics. thanks

[@wearethefruitoftheuniverse]

@@ArvinAsh what can be space-time like in our common day to day experiences? Gelatin Gelatin is like membrane of string theory Spacetime is ripple that is writing time code in particular fashion

[@steelgreyed]

KZbin algorythm doesn't handle videos above 15 minutes in length very well, unless you know what you are looking for you will go through a lot of trash and pseudo-science channels before Arvin Ash shows up, but by then you already know what quality is, or someone explicitly sent his link, word of mouth still works in the Digital World and Arvin's a diamond in the signal buzz.

[@charlesblithfield6182]

Arvin, the graphics on your videos and editing consistently impress me. I learn a lot more because of how skillfully you integrate the text with images.

[@Scott-qe4wy]

The graphics for timespace are inaccurate. They show a 2D representation of a 4D phenomenon. Timespace forms spheres or shells around all matter that warps inversely when a heavier object enters the field of a lighter object. It's not a flat trampoline.

[@charlesblithfield6182]

@@Scott-qe4wy I get what you said and have wondered about such representations. If imagining/rendering the 2D plane distortion across a third dimension can the spherical warping be be represented? It’s such a common demonstration of gravity, the rubber trampoline bowling ball demo in science museums…

[@projectw.a.a.p.f.t.a.d7762]

I hope I live long enough to see quantum mechanics and general reality come together.

[@AlirezaNabavian-eu6fz]

Yes I like to see them married...and also want to what the offsprings will prove

[@Packwatch2022]

I have been looking for something about this topic for what feels like forever! it felt like people would just say "it breaks down once you try to include gravity" and leave it at that-- thank you for such a clear explanation!

[@TiagoHansen]

Exactly! Congratulations on the video. Excellent explanation.

[@TheEncodedStar13]

This is one of the simplest explanation on this topic I have ever come across on internet. The graphics in video are super explanatory. In Physics, it is very important to have clear understanding of the most fundamental concept and your tremendous efforts to simplify such difficult subject are commendable.

[@cooper8473]

It’s crazy how you don’t have at least a million subscribers, this video was very easily understood by me (a junior in high school with a C in physics), and very well put together as well.

[@w花b]

He's almost there, don't worry

[@rhyvehr]

For anyone who's lost, the first question should be "Wth is Space Time, anyways?" Well, Let me help. Space = Meters Time = Seconds Force = Meters/seconds squared. The squaring of seconds makes it a curve on le graph. Tada, Forces = Space Time Curvature. It's literally just a more confusing term to use to make everyone feel dumb Welcome to Einstein did nothing useful 101 ( and anyone hero worshipping him is weird because ykno, he abused his wife who probably did the math and actual science for him, then he left her for his cousin. What a charming "genius")

[@josephdavis3472]

​@@rhyvehr I don't think your comment was on topic, warranted, or well explained. Nobody in this specific comment section mentioned Einstein. Anything I could look up on the subject shows that while they did often work together, he credited her for her contributions. But again, I's irrelevant anyway because nobody mentioned them. Second, nobody asked you to explain anything either, as nobody was lost. They were _specifically mentioning_ how the presenter did a great job of explaining, such that even a layman would understand. So finally, why did you decide to post that?

[@rhyvehr]

@@josephdavis3472 "huh duh im finna protect einstein" You're right, I'm sorry, I'm not someone with a C in physics. In university my physics mark was 40% above the rest of the class and my professor was like "what?" Physics isn't difficult to comprehend, physicists are, and translating between the two is hard. Why did I excel? Because I translated the presented information into ideas I can grasp and then didn't bother to study *literally anything presented*. The biggest problem *with this content* is that this is all theory, most of it is going to be wrong within a matter of years because someone's going to have a new theory. And so without a *concrete comprehension of what's going on* people create *bullshit ones* and then *become superstars to everyone else* acting like they understand it *when they really don't*. I'm unfortunately not everyone else. I'm someone who thinks firmly that those who have the ability to understand a concept, have the responsibility to help those who don't. I only actually watched to the point he mentioned einstein, and stopped watching, as that, to me, discredits the entire presentation because it's based off of flawed principles. Hence my explanation about einsteins theory of gravity and why it's bogus (because it wasn't actually a new idea, it was just rewording the definition of force) But you're right, here we go, i'm going to watch it. Yeah nope I can't do it, "cant predict black hole center blah blah blah" Yeah, I'm sorry, but nobody's finna have an idea of what's going on inside a black hole until we have a way of getting sensors inside of it. What does that mean? This video is speculation about speculation about speculation. That's a few too many speculation ^ 2'd for me. And that's actually really important to realize, none of this is actually in any way accurate, it's just someones idea of what *may* be accurate *with our remarkably bad ability to observe the phenomena* and they never really tell you that. And the mere fact that you right now, want to discredit the ideas i'm presenting because I used the word "finna" actually says alot about who *you* are, not who *I* am. And the fact that I know exactly what you were *finna* think right now is kinda sad, because you like to think of yourself as unique and smart and well thought-out, but you're well worded, not thought-out'. And now you're wanting to act like i'm being crazy for predicting that, and that's even funnier because you're still thinking you've thought anything this entire time.

[@rhyvehr]

@@josephdavis3472 Where'd you go man, I was actually really interested to see which angle you were going to take there.

[@Chon2052]

THANK YOU! Excellent explanation for people like me who doesn't know tons of physics (I'm a Pediatrician) but really like physics videos! Hope your Channel gets more subscribers, all of your team deserves it!

[@papasmamas1]

Check out the Fermilab youtube channel, also very easy to understand the basics.

[@Chipchap-xu6pk]

Once again, another fantastic video. You've done so much to help the public understand science, Arvin. Thanks! The perfect balance of not over simplifying and not making it a tangled web of maths. You treat your viewers like intelligent people.

[@ArvinAsh]

Thanks for that. Yes, I try to treat viewers as intelligent people who don't need to be coddled with oversimplifications.

[@theodorei.4278]

@@ArvinAsh If quantum mechanics is the correct one, then what does quantum mechanics say about gravitational effect of electorns or how they affect spacetime? Am I wrong to say that quantum mechanics say nothing about how the quantum particles affect spacetime? NOTHING AT ALL. And yet we always say that GR is not the correct, but we keep on a pedestal the QM. Very very concerned about the bias in favor of QM

[@johnfitzgerald8879]

@@theodorei.4278 I think not. See time mark 12:02 of the video. The video presents the problem in a nice visual. Energy bends space-time and space-time directs movement of energy. Mass is, of course, energy. I think that is the point of the problem. Feynman was able to find a solution to the infinity of the states between combination and decay of particles by eliminating many. When space-time is added in, all those possible virtual particle interactions between combination and decay also affect space-time. I am not entirely sure of the precision of the diagram, but it does show the virtual particles as bending space-time. Simply, an electron has mass. Mass curves space-time. But, see, that's not really science. Science is calculating how much spacetime is curved as a result of the total energy and mass. Clearly, all mass, from that of a black hole to that of an electron bends space-time into a sphere around it, at some radius. But there is the catch, at what radius would a photon orbit and electron? I would be inclined to believe that the radius is less than that of some effective radius of quantum uncertainty. But then again, that's where it becomes science. There is no "bias". QM and GR are both well established theories. But it is important to understand what a scientific theory is as it consists of a sub-theories, pieces that have different levels of strength. A scientific theory is a mathematical model that specifies the equivalence between different properties of nature. It is capable of predicting the outcome of an experiment. Type I parts of a theory have been experimentally demonstrated to be absolutely factual. Type II parts predict things that can be experimentally tested. Type III parts are inferences that can't be proven by some experiment as nobody has a clue how to even go about testing for that. Type IV makes predictions that are considered a bit difficult to believe, like anytime the math leads to an infinity. The current problem is that we can't get the equations of GR to link up to the equations of QM. But we know that both are correct in terms of the scale in which they have been measured. GR must emerge from some aspect of QM, just as molecules emerge from atoms, classical thermodynamics emerges from atoms and molecules.

[@theodorei.4278]

@@johnfitzgerald8879 once more you say that GR must coincide with QM at the quantum level. Be careful of the words you are selecting and the order you put them together, because you might sound biased. If you want to be neutral then you should say that GR must coincide with QM but also the other way around, I.e. QM must coincide with GR at the macroscopic level ( and I dont mean newtonian, I mean GR ). Which of course QM does not, because if from QM you could generate GR then the problem would have been solved and we wouldn't talk about this. So to wrap up, at best you can say BOTH theories are incomplete and they need to merge from one another. The video and you do not say that, you just assume that QM is the only well established theory and everything else must abide by this theory, which of course is not. So better talk about "General-Relativize" (if that is even a word) QM and not only quantized GR.

[@johnfitzgerald8879]

@@theodorei.4278 There seems to be a general lack of detailed understanding of how a theory works. A theory, like QM and GR, any theory in science, Newtonian mechanics, thermodynamics, is not an all encompassing. There is a scale of factuality and deduction, extending off into a degree of speculation and even sensationalized headlines. Knowing the difference is important. Generalized, sweeping, inspecific, fault finding statements of "It's all wrong and doesn't work cuz this" isn't functional.

[@adamgm84]

I've been looking for a video like this for a few months now. I can't get enough of quantizing gravity.

[@DeepThinkersClub]

Then you might like to see my theory…. 1st Page: kzbin.info/www/bejne/a5ykg6WQoZtprqs 2nd Page: kzbin.info/www/bejne/imTSoKVvnpJ4npo 3rd Page: kzbin.info/www/bejne/rYvWmaJjos6Vp6c

[@shethtejas104]

Like others have already mentioned, I have never seen a simpler video that deals with heavyweight topics like quantum gravity. Arvin, you are gifted seriously. Your videos are simple and easy to absorb by total amateurs but at the same time it also serves the right amount of details. Great job! I had read about these topics on wikipedia but never did I ever feel complete in my understanding. After watching your vid, I am now in a position to speak one line or two on why gravity doesn't work at quantum scales and why do we even need to merge the two realms.

[@jitulsarma1388]

Knowing something and teaching or explaining something are completely different things! I really loved your explanation Thank you!

[@Number6_]

If you can't teach it you don't know it .

[@BrazilianImperialist]

@@Number6_ Not true

[@jeanbriones1190]

@@BrazilianImperialist Very true

[@enzop2835]

@@jeanbriones1190 Not everyone has the skill to teach. That's a skill all on its own.

[@jeanbriones1190]

@@enzop2835 "If you can't explain it simply, you don't understand it well enough." - Albert Einstein

[@andoletube]

You explain very complex concepts in a way that is accessible to novice students. Great stuff!

[@DeepThinkersClub]

I figured it out! Check out my theory on here! 🤯

[@brendawilliams8062]

All I can say is be glad the tens floated and saved the cyclic pi or the boat would be absent many more present day oars.

[@andoletube]

@@brendawilliams8062 Is it time for your medication?

[@bryanchambers1964]

I'm a physicist and I thought that was very well explained.

[@Baghdadbatterymusic]

Amazing video. You explain things with so much clarity and in such simple to understand terms. You have a deep knowledge and understanding this subject and I'm thankful you took the time to break it down so well.

[@dr.pradeep6440]

Wonderful presentation ..

[@chrisalvino812]

Wow, that was an explanation of quantum gravity and its problems that even a lay person could understand. That was a super impressive piece of work!

[@jamesnasmith984]

Nothing I have seen brought me closer to an understanding like this presentation. Thank you.

[@LowellBoggs]

This is a great video Arvin, thanks! You always do such a great job of explaining things. I particularly like the fact that your graphics showed the Feinman diagram's with the gravity field distortions underneath them. I have heard similar explanations before but without that specific graphic, I did not grasp what the speaker was trying to say. Great job!

[@johnfitzgerald8879]

Small thing. I just learned yesterday that his name is spelled Feynman. I'd been spelling it as Feinmann too.

[@OfficialGOD]

@@johnfitzgerald8879 lol

[@ivocanevo]

That was one of the most approachable explanations I've ever seen. I hope that this is found by people who are interested in quantum gravity or the tension between relativity and quantum theory.

[@alexjaybrady]

Love your videos. I read Wikipedia on these subjects a lot but sometimes a video, an animation, or just your patient laying out of the issues is so much easier to grasp than pages of mathematical machinery to a layperson like me. Thanks a lot Arvin and crew!

[@tayzonday]

5:16 How would one even do a double-slit experiment with gravitational waves? Nothing blocks causality and it’s hard to articulate as an energy, though it does radiate 🤔

[@charleshansmann]

kzbin.info/www/bejne/lZqze4h3r7B-grc

[@Ben-ee2xy]

Yooo what’s up tay zonday

[@antonyguglielmone5430]

Test out heavy particles at ordinary vs. relativistic velocities? Might at least see time dilation effects 🤡

[@alwayscurious413]

Good question. My take is that anything that is wave like can be superposed as in interference. If gravity implies curved space and gravitational waves are thus a wave like oscillation or ripple of that space then in principle as we can superpose any waving fields together and generate interference it must be so for gravity. A bit like a standing wave on a drum or water passing through an aperture. That’s how I see it. Happy to be corrected if that isn’t right.

[@voidburger2989]

I've been binging these science videos recently and have been learning a lot about quantum mechanics, general relativity, and physics. Thanks so much for this great information

[@DeepThinkersClub]

Want to think outside the box? 😮1st Page: kzbin.info/www/bejne/a5ykg6WQoZtprqs 2nd Page: kzbin.info/www/bejne/imTSoKVvnpJ4npo 3rd Page: kzbin.info/www/bejne/rYvWmaJjos6Vp6c

[@Robertpupo]

Brilliant Arvin Ash as always - the reference to Wonderium even better - would strongly recommend if you can thread through your videos as a lecture series (over last few years) under different titles, that in itself too would be a great reference - amazing - appreciable efforts

[@jeffreymartin8448]

He has a way. Almost as if I'm sitting around with friends and a couple beers saying whatever we think.

[@pareeks]

Two things I do when watching Arvin speak: 1. Slow my watching speed to normal from 2x. 2. Constantly anxiously checking timeline if the video is not over Such the power of soothing voice and simple explanations of complex topics. 🙏🏾

[@pareeks]

Arvin I rhumbly equest you to open a channel in Hindi, translate same content, so that a large number of viewers.from remote villages in India gets Science in its most accurately discussed form. They are mugging up Bhors model, yet cracking IITs.

[@dj-kq4fz]

You do an amazing job of describing these concepts, Arvin. Thanks! Dave J

[@ArvinAsh]

Many thanks. Glad you enjoyed it!

[@omargaber3122]

I've tried for years to understand what they say (when we try to reconcile quantum mechanics with gravity, things go to infinity) but I didn't understand it, I wish I could see it in mathematical equations to understand it more Also, I hope to understand the meaning of their saying ( gravity is non-normalization) with mathematical equations thank you my friend

[@Primitarian]

This was so great I may be getting greedy, but I'll ask anyway: Would it be possible to go into more detail on how Feynman, et al, canceled infinities as part of renormalization?

[@Primitarian]

@Opterongeek Or it's a mathematical tool by which to facilitate accurate calculations, one of the two.

[@Primitarian]

@Opterongeek Are you saying that this gives you a right of ownership? Since you wrote some of these variables down, as you say, nobody else gets to comment on them, they're yours?

[@Primitarian]

@Opterongeek How have all of us been treating you?

[@korakys]

Looking at your animation of the double slit it made me think that a particle is an instantaneous "condensation" of the energy field foam into a point particle. I like this as a visualisation.

[@BlueFrenzy]

I have a friend that said once while smoked something in the direction of "of course, if you spend the energy of the particle to interact at one specific point, there's no more energy to be able to interact elsewhere". So serious.

[@ascensionunlimited4182]

Sort of like a how a wave crashes and the air and water at a moment are in a churn or mixing of the boundary layer (at fractally proportionate scales no less) only to coalesce into its separate constituent particles. Thus deciding its particle state. Literally from a wave function. Nature speaks volumes if we stop and listen

[@StorytellerStudios]

Your wonderful videos never cease to amaze me. Describing the indescribable is a tough assignment, and doing it with a language most of us don't speak. Fantastic! Thank you!

[@rhyvehr]

For anyone who's lost, the first question should be "Wth is Space Time, anyways?" Well, Let me help. Space = Meters Time = Seconds Force = Meters/seconds squared. The squaring of seconds makes it a curve on le graph. Tada, Forces = Space Time Curvature. It's literally just a more confusing term to use to make everyone feel dumb Welcome to Einstein did nothing useful 101 ( and anyone hero worshipping him is weird because ykno, he abused his wife who probably did the math and actual science for him, then he left her for his cousin. What a charming "genius")

[@johndoeofficial4357]

Is it time relative at quantum level? Or the quantum waves form the space-time?

[@macronencer]

Great explanation! Oddly enough, I'm reading about this very topic right now in Sean Carroll's "Something Deeply Hidden". I've peeked ahead and the next chapter has Feynman diagrams in it so I think there's a well-trodden path being followed here (I know that Sean is also going to discuss entanglement as the basis of proximity though, which is the bit that I'm curious about).

[@ArvinAsh]

That's a good book. I'v read it, and even did an interview with Sean on my channel.

[@macronencer]

@@ArvinAsh I saw that interview, yes! His podcast is also great: he interviews some incredibly interesting and informative people.

[@Italianjedi7]

Wonderful video Arvin. Really helped me understand how complex gravity is.

[@Solemn_Kaizoku]

The quality explanations and animations in these videos is far above anything else I've watched regarding quantum physics. I come away feeling like I almost understand (at some level, at least). Well done, Arvin!

[@feynstein1004]

I think trying to reconcile QM and GR is the wrong approach. QM is all about *matter-matter interactions* while GR is all about *matter-spacetime interactions* They're completely different things. Asking why the two theories aren't compatible is like asking why a ball dropped to the floor bounces but the same ball dropped in water sinks instead of bouncing.

[@feynstein1004]

@Darren Murphy What?

[@Rex.404]

There gotta be some connection somewhere that we just can’t find yet. The probability ain’t zero for sure.

[@feynstein1004]

@@Rex.404 Hmm idk

[@CareBear-z9w]

You both tryna act smart gravity isn’t quantum it can’t have a force carrier it would require a superposition of gravity acting force acrriers

[@vogelvogeltje]

@@CareBear-z9w why are nerds so fucking hostile with each other 😂 chill bro, you can have a discourse without ad-hominem.

[@cmilkau]

Renormalization might not be necessary if you have better number systems than the real numbers. In theory you can make a number line that can fit a copy of itself between any two (distinct)numbers without any distortion (just zoom-like rescaling), even between two numbers that are so close that their distance is smaller than any positive real number. That would allow you to fit the entire universe into a single point (well, in real numbers it would be a point, and from outside it would look like a point), but you could still walk around inside it, possibly not even noticing anything unusual.

[@OmniGuy]

Once again, Mr. Ash, you have made clear to me what I've never quite been able to understand watching other videos. What the conflict is with relativity and the quantum world. Where the hell is it's gravitational effect. Well done. Again. No, very well done.....my friend.

[@howtheworldworks3]

It seems to me that subatomic particles expand into a very large area when they have to move and all that expanded blob is their gravity combined and when they hit something or are stationary, they are forced to contract into a single point again. That's the reason why the point where they form on collision can't be determined. because of the large expanded size they can have any of their parts move faster or slower and have it's shape change while traveling and whitchever part gets to have a larger density at the moment of impact, the rest of it's body contracts over there. It feel to me that subatomic particles act a little bit like cells but unlike cells and other solid macro scale matter, the subatomic particles have huge spaces of influece where they can contract and expand. If there is such a huge amount of space between an atomic nucleus and the electrons around it then that way of organising may be even more extreme at the smaller scale. And that also coincides with the way bodies at the huge scale work. The sun and the planet are tiny dots compared to the massive patches of space between them and yet if you were to look at a huge distance you kinda see galaxies as compact bodies with very little space inbetween stars. That's an illusion given by scale or distance.

[@anishashee8511]

Great video and very well explained 👏

[@dan7291able]

Damn, great video dude, it's all stuff we all mostly know too but its the way you pieced it all together for a decent explanation is what stands out. Thanks Arvin, keep it up

[@stephanieparker1250]

This video is fantastic, well done! Gives an easy to understand frame work of the issue and what scientists are actually working on for a solution. Great graphics, too!

[@maxwell8758]

Quantum gravity is my future field of research. I intend to solve it, or die trying.

[@stevenyoutsey8989]

Arvin, this explanation was simply fantastic. Like others have said, the coupling with illustrations was fantastic and by far the simplest explanation. Thank you!

[@pasijutaulietuviuesas9174]

Fantastic video. One thing I missed was how renormalization works. When learning about infinite divergent sums, I've learned of several different summation methods, such as Cesaro, Ramanujan summation and others. If I remember correctly, it was specifically Ramanujan summation that was used to renormalise sums in QFT. I'm curious how exactly it's used and in what specific problems it's used to remove infinities in QFT?

[@Reddles37]

I don't know the exact mathematical terminology, but basically whenever you have a Feynman diagram with a loop you have to integrate over the possible momentum going around the loop. And this can go up to infinite momentum, which tends to cause the integrals to blow up. But what you can do is find another matching diagram which gives a contribution with the opposite sign, and then cancel out the infinities from the two diagrams. In practice what you usually do is put in a maximum momentum cutoff for these loops to keep everything finite, and then when you add the contributions from all the possible diagrams all the terms depending on the cutoff should cancel out.

[@Anonymous-df8it]

@@Reddles37 Why does this fail for gravity?

[@In20xx]

You're a great teacher. Thanks for making this!

[@alexbowman7582]

Does antimatter have antigravity? If we had antimatter in a vacuum and it fell down would it prove that antimatter has + gravity? Well no, because perhaps antimatter also has antitime so it’s not falling down it’s falling up but in reverse time. This could explain the problem with classical Big Bang where roughly equal amounts of matter and antimatter were produced and didn’t mutually destroy each other because they didn’t meet in time, our Universe went forward in time, the antimatter Universe went backwards in time.

[@dray7579]

Thanks Arvin, I have asked that question for a very long time. How can gravity have a particle when its curvature? And finally you answered it and i totally understand. Which is saying alot about your skills. Im just going to say it, man i love you.😥

[@ArvinAsh]

Thanks buddy. Love you back.

[@lavkmr1]

Hey why all planets are circular . Because they are supposed to be due to curvature of space time

[@leon_noel1687]

This could be the best Video ever created in the universe. I'm not even joking. The most important problem, presented so that everybody can understand the basics. Also it's a peace of art.

[@payattention6114]

Best illustration and way of explaining qm I have seen so far. Thank you

[@DB-oc5kh]

Amazing video. You made such a complex thing into something the every day person can somewhat understand. 10/10 GREAT JOB.

[@maddoghel]

Do we have to rule out the possibility that the space-time continuum is actually a wave form?.. If so, why? Isn't it the easiest way to explain the various fluctuations ascribed to various forces -and gravity too, as well? Your videos, Arvin Ash, are surely "food for brains" and I thank you about it! Looking forward for your next, but I'd appreciate any reply to my question, too!

[@Argon_John]

This was really well explained from start to finish

[@glennabate1708]

What scale does the quantum world end and the classical world begin?

[@SumitPrasaduniverse]

Thank you for explaining this topic in such a simple way 👌

[@Dxeus]

When Arvin talk about his sponsors, his face changes with a bit of smile. 😆 I got you. Love your videos.

[@DrRick-dq4bb]

Best explanation of gravity I have ever heard. Gravity may not have a quantum explanation as it is not a force.

[@iam6424]

Why gravity must work at small scales ? Is it an assumption tht it should ?Also tht thing/assumption about cumulative effects must work at large scales ?

[@amjadalhindi7350]

Because if it didn't, then how can we say it's a broad explanation of the universe? This is how theories must be, broad, unified, and applicable at all situations, not just certain phenomena

[@Cats2Fat]

Even if gravity didn’t work at small scales, you would still need a theory to explain the emergence of large scale gravitational effects.

[@ArvinAsh]

precisely!

[@iam6424]

All this makes me think...That theories come out of conscious minds 🙏🏼 So one day Science must proceed into the inner subjective world 🙏🏼

[@CaptainPeterRMiller]

I'm here again Arvin. Thanks for the explaining note. This looks very good. Cap.

[@ArvinAsh]

Welcome back Captain!

[@CaptainPeterRMiller]

@@ArvinAsh That was a great video. I feel you need a greater audience. I endeavour to spread the word. Thanks Arvin. Great to be back.

[@marishkagrayson]

Arvin, love the music selection! ❤ The subject matter is fantastic too!

[@LionThrone]

Excellent video Arvin. Really interesting. Regarding the disparity between the General Theory of Relativity and Quantum Mechanics (and I'm not a physicist and only have a very basic understanding of both), but relating particularly to the discussion on infinites and wave theory, could it be as simple as it doesn't matter what form the particle is - electron, proton, neutron, meson, quark, etc - it's simply the aggregate mass of that 'system' (or quantum object) if you have both particle and wave? Sorry if I'm completely off

[@jackhill2765]

Arvin, great video! Although pretty much all of your videos are very well done and informative, every now and then you conjure up one of a kind pinnacle performances. This video when coupled with the Loop Quantum Gravity (LQG) vs. String theory ST video is a double grand slam. I have watched/read countless videos/articles purporting to explain where it is that General Relativity (GR) and Quantum Mechanics (QM) are incompatible, most with condescending pats on the head and marginally appropriate metaphors whose connection with the topic is often more confusing than the original question. I mostly come away with a slightly out of focus understanding and the vague feeling that the answer was somehow just out of reach, like with QM itself. Maybe the answers were obvious to others, but having watched your two videos several times, I conclude, you have put your finger precisely on the jugular, explicitly listing concrete issues with crystal clear language and animation, and at a perfect level of abstraction. The fog is lifted, as one might experience the world anew following cataract surgery. 1. A QM wave (before measurement) is probabilistically dispersed in space, while in GR, gravitational sources are localized. 2. QM operates against the fabric of space-time while gravity in GR is the warpage of the fabric of space-time. 3. And, woven into the discussion, QM is quantized while GR is continuous (analog). Personally, I suspect that the fundamental problem is with the continuous space postulate of GR. A solution to Zeno's various paradoxes supports the position that space is quantized as is clearly illustrated in the following video: kzbin.info/www/bejne/n4aYaoZrf6mjibc Finally, midway through I picked up on the intuition that that final solution lies with somehow combining LQG and ST, with the strings, rather than the loops, perhaps forming the fabric of space-time. Excellent job! Thank you very much! Jack Hill+

[@goldwhitedragon]

Wouldn't that fabric itself require a background?

[@gierdziui9003]

it is all just a simulation, and quantum phenomena such as planck lenghts etc are just limitation of floating point calculations

[@jackhill2765]

@@goldwhitedragon I can convince myself that the loops/strings would be the background with "nothing" beyond that, but this is just a mental model of how reality might be. And, envisioning exactly what the "nothing" would be is difficult at best and maybe impossible for humans to comprehend.

[@jackhill2765]

@@gierdziui9003 I agree that the simulation hypothesis is more likely than most people are willing to concede. And in the current era, most simulations are produced on digital computers so this is a natural metaphor for our age. But these simulations don't directly influence physical reality without a physical interface, i.e. airplane simulations don't actually fly nor do simulated tornados blow away buildings. Personally, I believe that infinities are a logical impossibility, at least in certain situations (i.e. Zeno's paradoxes or for physical movement generally), so that having a minimal unit of space-time is a logical requirement rather than a technical or mathematical issue.

[@gierdziui9003]

@@jackhill2765 Yes, I agree that digital simulations are probably not a 1:1 transformation nor explanation why our world seems to have such boundaries - reality might be infinitely more complex than our computer simulations. Things I think about the most lately are how exactly someone can determine they actually are in a simulation? Let's say i play a computer game and for a moment get into the perspective of the player. Let's assume the game is minecraft, for example. How can I determine that I am, in fact, in a simulated world? Looking for answers to this and by model-like analogy, I think we could try to answer quantum phenomena in simulation theory based research. So not really looking at our world as a digital simulation, but as "*a simulation*" and find out how that it is a simulation assuming we know how we can conclusively find this in games and other world symulators. For me, this is a really fascinating concept that I hope I will be able to research in the future. After all, finding the core of the simulation (if there is such) will automatically obsolete ALL current understanding in every field by essentialy comparing them to *magic that somehow works* instead of ojr current, really weird assumption, that math is even formulated the right way. I hope you get the point :D

[@syntaxed2]

I do wonder if Susskinds idea of ER = EPR could explain those missing 9 spatial string dimensions...they could be inside the ER bridge? or hell, there could be 9 bridges :)

[@OchiiDinUmbraa]

"It is not incorrect,its incomplete" Sounds like me when i try to explain my math teacher why i deserve a point

[@ArvinAsh]

Haha. Feel free to plagiarize that line my friend!

[@omargoodman2999]

@@ArvinAsh When you steal ideas from one person, it's plagiarism; from many, research.

[@vijaysahani3464]

Thank you Arvin sir, you make my understanding simple by putting Feyman Diagram into the explanation of gravity.

[@alexandermcclure6185]

This explained the idea of the Graviton very well. I always thought, "It's just curvature! Curves are continuous!" But this showed me the biggest flaw: Superpositions! Where would the gravity of a quantum object emanate from? It could average out, but then measuring a quantum state could remove a gravity well from far away, which doesn't seem quite right. Thanks Arvin!

[@waytoomuchtimeonmyhands]

It would be interesting to hear your take on the EP=EPR hypothesis. Interesting idea that space-time may be an emergent phenomenon of entanglement.

[@StephenGillie]

The theory that locations in spacetime are only next to each other because they're very tightly entangled leads to the concept that you can change what's next to a given patch of spacetime by entangling it with a remote part of spacetime. Vacuum energy is spacetime maintaining locality by entangling with neighbors. To create a portal you could entangle 2 photons, leave 1 at a location, goto a different location, then use the 2 photons to entangle spacetime and create a portal. And if you believe in Remote Viewing, it could be a read-only version of Remote Entanglement, where one part of spacetime (or the beings there) could affect another part of spacetime.

[@AlexanderShamov]

​@@StephenGillie You can't transport information through entanglement, so these "entanglement wormholes" are supposed to be non-traversable.

[@StephenGillie]

​@@AlexanderShamov It feels like there should be some way, as though we just haven't figured out a clever way yet. Like we measure Z for a 0 and "anti-Z" for 1, where "anti-Z" might be halfway between X and Y. Though since point particles act like they are spinning spheres, maybe it's mathematically impossible to determine how one will respond to a measurement.

[@theklaus7436]

This double slit experiment- has it ever been done in a none gravitational room! ( or in the space? ) I wonder if it would change the slightest! Dirac used the special relativity theory but this QFT is also incomplete!. And no I don’t feel bad. 😊

[@Nosirt]

The whole point is the gravity is not a force that is mediated by particle- it’s the actual curve of space itself. So a non l gravitational room, or experimenting in space makes no difference. The particle you are experimenting still have mass- therefore, gravity is present. Asking if you can test it in non gravational space is like asking if you can test the wetness of water in a non wet surface - the logical is, the test itself warrants the wetness.

[@HKLpodcast]

Gravity is a less a force and more of an interaction/ distorting of space that increases exponentially with size. When you look at the quantam scale, the distortion of space is so extremely small/weak and almost non existent that the other forces over power it.

[@safebox36]

The one thing I still can't get my head around, even at a basic level, is the existence of virtual particles. Every time I try to read about them, the info always says they don't exist except in the maths to fill in supposed gaps. But then some black hole papers have suggested that Hawking radiation comes out of the event horizon via virtual particles failing to annihilate with its anti-particle. So do VP exist or what? It is really confusing.

[@christianthom5148]

Keep digging on the Hawking radiation, I have seen (or read) somewhere that it has nothing to do with virtual particles.

[@ronaldkemp3952]

Astrophysicists have been measuring massive amounts of energy and matter flowing rapidly away from the supermassive black hole in the core of our galaxy for quite some time now. Hawking came up with his Hawking radiation claiming pairs of particles were emerging just outside the event horizon of a black hole to try and explain the energy and matter observed to be moving away from the Sgr A* while keeping general relativity afloat as the prevailing theory. However, if nothing is able to escape the gravity of a black hole then why would anything be able to escape? So basically Hawking radiation violates Einstein's equations on gravity. In reality they were both wrong. They both neglected to include the action causing gravity in their equations. If they had included the action then the massive amounts of energy and particles streaming away from the supermassive black hole would have been easily explained. Research pair production theory. The particles don't come from nothing. When energy interacts with matter, external EM fields or comes to a rest relative to the body producing the EM field pairs of particles pop into existence. The energy according to the laws of conservation converts into elementary particles, a positive and negative particle. That's why it's called pair production because pairs of oppositely charged particles emerge out of the energy.

[@ichigo_nyanko]

The virtual particle explanation of hawking radiation is just a simplification hawking came up with to explain it to laypeople, iirc he really regretted it for the confusion it caused. It is actually caused by (and this is yet another simplification) due relativity causing the measured zero point energy at the black hole and from an observer infinitely far away to be different. Hawking discovered it while trying to mix relativity with quantum mechanics and found Hawking radiation to be one of the consequences.

[@johnfitzgerald8879]

I understood that Hawking Radiation was virtual particles as well. Perhaps that has been updated. Here is where we have to be careful. There is science established by experiment that is well established as being real. We can see the tracks left by particles in a cloud chamber and from collisions of the LHC and others. And, we have a successful theory that predicted them. There is an issue, we must take care of, that the theory is only solid on the grounds of what has been successfully observed. Anything else it predicts is not established and the theory could have some detail wrong. Theories of prediction are, as a requirement, simplified models of nature. The theories have their mathematical parts and mathematical models have a habit of producing equations where things go to infinity. Standard physics does this in places where there are oscillations. The equations would tell us that voltages go to infinity, bridges in the wind are driven to infinite amplitude swings, etc. That is generally where things blow up as nature gets more complicated than the basic theory. As far as we know, infinity exists only in mathematics. So far, aside from things just blowing up, Einstein showed that velocity doesn't go to infinity, only up to light speed. Einstein's General Relativity was curious in it's prediction of singularities when piling up more and more mass. The resistance to accept that is reasonable as we know nature abhors an infinity. Stars do resist infinities in nature as they start to collapse, they explode. That, despite their struggle against it, blackholes do exist and it is quite remarkable. Still, we actually don't know what is inside a black hole, so we don't know that it validates the singularity, only the run up to one. The problem for us is we need to distinguish between what part of the theory has been measured to be real and what part is an unvalidated prediction of an otherwise well validated theory. In particle physics, there is some complaint of the theory predicting particles that don't exist. That's a tough logic statement there because simply we can only know what we found, not what we did not find. I would have to review the KZbin video that highlights this. Heisenberg's uncertainty is clearly true, we have experimental evidence of it, right? Well, it explains a lot, that's for sure. And being what it is, the undeniable inference is that virtual particles blip in and out of existence. Have we measured them? And is there, perhaps, a difference between the context of a black hole and the context of Feynman particle transformations? The video says, "an infinite number of combinations of interactions". And this is why the research still goes on. When it comes to physics, there are the two parts of it, what it is proven to predict properly and what is predicted that isn't experimentally verified. Really, what theoretical physicist are doing is trying to predict what the experimenters should be doing next. Whatever hasn't been proven to be wrong in a theory that successfully predicts everything that has been tested is assumed to be true until proven otherwise. The theory continues to be developed until it can predict something that experimenters can test for so the theory can be further validated or some element proven wrong. Christian Thom's comment seems to suggest that virtual particles haven't been show to be real. Perhaps there is another explanation of Hawking Radiation that doesn't depend on VPs. And while this idea of VPs in Feynman physics is certainly justified by quantum uncertainty, I don't know that has been proven. And seeing as it yields an infinite number of VPs and all these have to be accounted for and then renormalization applied to get rid of it, this seems to be an issue. And now we know that adding gravity in makes it worse. Welp, there's what I got until encountering the usual "Brain.exe has stopped". Could be worse, I could be completely unable to remember I wrote it, like 10 Second Tom and 30 Second Clive.

[@caricue]

@@johnfitzgerald8879 I liked your insights into this interesting subject. If you've ever watched Sabine Hossenfelder's videos you know that she acknowledged that particle physicists will say that a particle exists if it is useful to explain an observation. You are not going to see any traces of bosons or quarks in any cloud chamber. I also don't like all the emphasis put on obscure experimental results like the double slit. The results are beyond weird but easily observed, so while "something" is happening there, I don't think this warrants so many outlandish interpretations. It's just an oddity of nature that you can conjure in this artificial situation in a lab. An example of taking a very structured experiment way too far concerns causation. You can isolate and explore the effects of one variable by controlling everything else, but this doesn't happen in nature. Outside of a lab, everything causes everything, but you will still have scientists try to say that their one variable "determines" what happens. They then use their memory to concoct intricate "chains of causation" that they believe are real as opposed to imaginary. I see much of physics now consisting of these sorts of imaginary theories that are only loosely based on obscure experimental results that might not mean anything.

[@starchild2121]

I sense a disturbance in the force....

[@frun]

LQG is an effective theory. It is like a quantization of sound waves 🌊.

[@s700wattsyoung8]

Very well done. This episode reminds me of a question and a recent debate. If a Plank length is the smallest possible known theoretical unit, does this not suggest a theoretical limit for Pi? A plank Pi if you will… :-)

[@reisilva2940]

actually no, because you can enlarge your circle as much as you want, and the precision of pi would also increase accordingly with the irracional number

[@JasonKlein97]

@@reisilva2940 This is only true if the universe is infinite. If the universe if finite, it would mean that pi has a limit. Interesting thought!

[@reisilva2940]

@@JasonKlein97 pi is an abstraction it has no limit. Since the universe is expanding the most precise measurement of pi needed for a physical thing also grows, but I don’t think it is a particularly meaningful thing, just a coincidence, just like the best approximation for square root 2 needed to measure the diagonal of biggest square which fits in the universe, even if u call it the plank square root of 2 I just don’t think its a meaningful term.

[@Kay_Gee_]

Around 3rd or 4th standard I asked my teacher why exactly does the gravity exist when he was telling us how things fall due to the gravity. To this day I’m looking for answer. I really didn’t think gravity would be the one so mysterious compared to all the wild things we know about quantum mechanics.

[@ArvinAsh]

Science really can't answer why question, but mostly what and how questions.

[@NotSoOpposite]

It's comprehending videos like this that truly make me think I'm supposed to be back in school progressing unorthodox experiments; even if it means getting the lesser grade, because I often found myself debating with teachers/professors over irrelevant things - that have yet to ever been proven significant in life. Was rarely, if ever proven wrong: only told that people choose to believe different

[@abistonservices9249]

Gravity it seems to me seems a very strange medium, as it is also part of spacetime. I think black holes have a lot of mystery as part of this, as gravity being a weak force is extremely strong in a black hole. When we find out more about black holes, maybe they will give us a clue. I am just an interested bystander!

[@steveb5210]

All, Gravity is a FORCE!!! The resultant maybe a distortion of space time but gravity is a FORCE!! Distortion of space does not push you into a mass! The ball on a canvas is representative only as an example of rotation/angular speeds to maintain an orbit but that’s all! Gravity is an interaction between mass and black matter/energy. The interaction results in a force. Black matter is not matter as we view it, it is energy. Density is nothing more then a packing of particles and particles are nothing more then energy. The interaction of both energies create gravity (a force) which is energy also! Figure out black matter and you will not only figure out gravity but also the unified equation!

[@angeldroidcs4962]

This is such a great video

[@9a8szmf79g9]

Perfect visual representations along with the explanations.

[@luizotavio2116]

But what if gravity just doesn't exist in quantum scales? Is it possible that it's just an emergent quality of space-time?

[@guillaumeeybert-bouillier5628]

You are a genius to making this video ! You manadge to mix thé best part of physics and math ! From m'y point of view this is a better way of doing physics then i ever have in lessons!

[@guymcdudeman9030]

This is probably the first explanation of the issues with gravity in GR & QP that not only mentioned that in GR gravity is not a force, but also went into a detailed explanation of what that meant and also covered some of the attempts at solutions to those issues. Very well laid out discussion from beginning to end. My thinking has always been that the most obvious reason that GR and Quantum Physics don't mesh is Time. It's very prominent in GR and almost completely absent from QP. It's all about space-time in GR. In QP, there is no "time carrying" particle, but no one seems to notice. Time is a dimensional aspect of where particles, or more precisely, localized anomalies in quantum fields, exist. Without the dimension of time, I don't think you can have gravity, can you? And while we're at it, what, exactly, are the fields of quantum field theory? They seem to be a more scientific sounding concept of the aether that Aristotle or Descartes described. They seem to simply be taken for granted that they exist, and that's all. Perhaps you could make a video describing that more thoroughly, too? Thanks again for your very well-made videos.

[@SkyDarmos]

Newtons laws break down everywhere, not just at high energies or small scales.

[@servusdedurantem]

I am a physician but took interest in what is quantum and this is the best and simplest video I found that even a non math person can understand thnx

[@barnabywilde374]

thanks for explaining what "won't quantify" means as it's so often invoked in conversation without explanation.

[@nickmorgan5144]

Nobody has ever explained the issue with quantizing gravity as well as you did in this video. I've listened to so many physicists talking about the topic, but none of them have explained that the problem liest with wave-functions and localising gravitational effects. Might be obvious to some, but it certainly wasn't to me.

[@X-Gen-001]

Re: The discrepancy between general relativity and quantum mechanics. *I think the answer lies in quantum entanglement.* Also the arrow of time reduces to 50/50 % at quantum scales. Example: electron < - > positron. So the more complex the system is, the greater the probability is for entropy to increase. And increasing entropy of course is what we see as the forward passage of time. When we see a particle as waves, we're seeing all of its alternate timelines meshed together. When we measure it, the wave function collapses and we see only one of its possible timelines.

[@juwitzkeold]

This video explains different interesting topics and their relationships in a very simply way. Thank you for that.

[@srenkierkegaard6433]

This is by far the simplest and clearest explanation of why there's no theory of Quantum Gravity yet.

[@cypherparadigm3428]

Imagine you're a fish swimming in the ocean. And you go from Point A to Point B everyday. Somedays you get to Point B much faster than you do usually, and some days it takes much longer than usual. You watch the weather forecast everyday, and you are positive it's the ocean current causing you to take more or less time to get from Point A to point B. Its the only logical explanation right. Then why do you make it in fast, normal and slow speeds. If the currents were the only force you were up against, you should have two speeds. It's because sometimes the water is saltier. Sometimes the water is thicker. So not only are you fighting the current, you are also fighting the density of the current, which changes based on the allocation of the dense particles. All of that can be defined, all of it can be precisely located and accounted for, but if you don't know what salt is, you can't know how it travels through water.

[@hometheatre1706]

I given to believe that this topic about gravity had been addressed/explained adequately well (in my opinion) by both Matt and Nick (from PBS Spacetime and Science Asylum, respectively). Go look for their videos on gravity at their channels. Matt uses two moving kayaks as an analogy, while Nick uses a squirrel. Ok, no more spoilers...go view that for yourselves, those of you curious to know what is gravity and how it works. Anyway thanks Arvin for covering this topic along with QM! Very interesting indeed. Did learn a couple of other new things, related to the discussion. Cheers!

[@Trizzer89]

If Einstein is right and gravity is just warped spacetime, then of course quanta will never explain it. I do believe he was mostly right, but I also believe in variable speed-of-light (while passing through a gravitational field)

[@factsfinder4359]

I always watch your videos because you got skill of converting difficult phenomenon into easy ones.

[@ArvinAsh]

Thank you. Glad you enjoy these videos.

[@Tydusis1]

This is quite fascinating! I hadn't considered this before watching, but it seems to me that if they are to reconcile without some crazy new physics, then quantum gravity seems to imply that gravity is fuzzy at small scales. Which sorta implies that time is fuzzy as well, since the probabilistic shifting of a quantum wave of gravity moving through space means that the flow of time is also shifting probabilistically around objects with gravity.

[@seanmostert4213]

The fabric visually speaking is cross crossing vortices of vibration. The fabric is force. The vortices, being force and not matter, can exist at all vibration frequencies at the same time, meaning that the same fabric pattern that exists at one scale repeats again at both a smaller scale and a larger scale at the same time. The cross crossing fabric of force can be seen in matter, such as trees and plants growing in a spiral out of the ground, and the bark of trees showing a cross cross pattern as it goes up the tree on many trees. The pattern can also be seen on the surface of water such as large bodies of water like lakes, oceans etc. which can be seen at different elevations even from a plan. Also on the top surface of water as it pours out from a jug into a cup, and as the water falls it rotates from one orientation to another in 90 degree increments as it falls through the different layers of the fabric. Many other examples to demonstrate if anyone would like further info.

[@StephenJohnson-jb7xe]

Is it possible that below a certain size/mass threshold (possibly distance too) other forces overwhelm gravity and above that threshold they don't leading to our inability to "make " it work at a quantum level?

[@SaltyBob355]

Wow! What an excellent presentation in a way I can understand!

[@NicoleGahl]

Maybe gravity makes the wave function or vise versa.

[@jayb5596]

Look up node edging, weighted and unweighted and once you understand the function, apply it to the nuclei of the proton, the egdes or connections between the quarks. The gluon field and all the activity inside the proton is the weighted measure being applied to the matter. When we are in a free fall we are in an unweighted state of measure and when we are at rest in a field we are in a weighted state of measure. Once you understand the function it becomes a little more understandable. Something to ponder.

[@Evghenios79]

Arvin, in my limited knowledge of this area of science, I see spacetime as a monitor screen whereby time (and photons) act as the "refresh rate" With photons serving also a "change state" role. We are "encoded" onto the monitor screen itself