Is Quantum Mechanics or General Relativity More Fundamental?
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- čas přidán 3. 06. 2018
- A discussion between Sean Carroll and Matthew Leifer, with questions from other attendees, at the California Quantum Interpretation Network meeting, June 2018.
This recording was made hastily and informally with a phone; sound quality isn't great, and questions are almost inaudible. Sorry.
sites.google.com/site/califor... - Věda a technologie
Sean Carroll clearly paid more attention during school than I did.
He graduated during his kindergarten year!!!
Sean is so smart, the wine gets drunk off of him.
I love that you have made this available regardless of any sound quality issues. Thank you so much!
Cam Spiers what sound quality issues? Everything sounded perfectly understandable.
In the description the video uploader noted the following: "This recording was made hastily and informally with a phone; sound quality isn't great, and questions are almost inaudible. Sorry."
To Serve Man yeah at first glance I got the whiff of a backhanded compliment. I don’t think that was intentional but, who knows.
I was trying to make them aware that I appreciated the video and it being uploaded regardless of any perceived audio issues. Like you I didn't find the audio bad.
Sean Carroll, you and Brian Green I love so much for being best teachers with wonderful ability to communicate complex ideas of physics in easy manner, I wish you both long lives, love from Pakistan
Wonderful to see interest in the real questions of physics from in my home country's humble community in Pak!
You have an amazing way of explaining your position clearly without going off on tangents that is a quality most professors don't have
Well, this video shatters any illusions created by Carroll's other videos that his work is something an interested layman can understand by watching videos.
He does a great job of dumbing it down for the rest of us.
Even people who study this at postgraduate level find it difficult to fully appreciate what these theories imply.
"If you think that you understand quantum mechanics then you don't understand quantum mechanics"
~Richard Feynman
I keep trying, but I get lost. I keep listening because, quite frankly I am in love with Sean Carroll. I'd listen to him reading the phone book 😂
Being subscribed to your channel for like 4 years has finally paid off. =) Thanks for this Sean!
The bartender said: We don't serve your kind here. Get out!
A tachyon walks into a bar.
Must be a very very high energy tachyon up to no good, to be going that slow. I wouldn't serve him either.
you know its bad when the bar needs tamazepam
(because its unstable)
The tachyon travels so fast that the joke should be.
The tachyon walks into a bar..
Two weeks later: Bartender, hey we dont serv your kind here, get out. lol
While some long-dead curious Austrian-Irish philanderer's abandoned cat yowls by the bar stools...
I thought it was a reverse causality joke and had my laugh, then I read the comments.
Is that Alanis ironic?
This is interesting because I'm sure that they could switch the position that they're defending and be just as sure and articulate. The reason that the unification of GR and Quantum Mechanics is so sought after is that we're pretty sure that they both have some fundamental truth. The foundational interpretation of QM is maybe the most interesting question in physics yet is kind of under represented among people practicing it. It's an absolute gift that people like Carroll are debating it in public.
This argument was no contest before it began, which only became more clear as it evolved.
This talk was excellent but i have one quibble with Sean. He claimed, liked many others, that Einstein believed that spacetime had a fundamental existence independent of anything else. "it is the stage upon which stuff happens." In fact, Einstein said this in 1921:
"Since the properties of space appear to be conditioned by matter, space is no longer a precondition for matter in the new theory. The theory of space (geometry) and time can no longer be treated before physics proper or developed independently of mechanics and gravitation."
It seems to me that he was suggesting that spacetime was not fundamental and must be emergent.
Thank you sir! I love that this is way over my head, yet can sit in the back and hmmm.
This is really nice. I hope there will be more in the future.
Sean's wine glass is in a superposition of "empty" and "full" ;-D
This channel needs more views and subs. I love Sean Carroll. Just incredible
Goblet of wine versus a Plastic Cup? Interesting. Go on....
Thanks for your support prof Sean Carroll
..I'm with Sean on quantum mechanics being more fundamental...
The energy, which is being applied from within the planet's core, is what creates gravity and not because of the size of the planet, its mass, or by space-time curvature. ~Guadalupe Guerra
As always,Sean Carroll is the best!!
Bonus: David Wallace asking intelligent and informative questions...around 33:00..his voice and phrasing are unmistakable!
I really love Mr. Sean Carroll! :) Now I love physics even more hahaha
I never considered the possibility that there might be something more fundamental than either of these ways of looking at the world.
Look at them in analogy. Quantum rules are like rules of a lottery. Very exact measures, and rules but with probability involved. Relativity is the rules you apply when you win. The underlying dynamic field powering it all. the "M Theory" in the lottery is the dynamics of money. Not the same rules but not incompatible. Elegant solution.
I'm with the Equivalence Principle when and where timespace is local and very small but still classically small in an inertial or noninertial frame .
I thought the discussion was great and to watch the expressions on the debaters faces was priceless ! Good to see the smartest people challenged by one another n not go postal ! Now if only we could get the rest of America to b so amicable , and learn to understand opposing views ! TEACH THEM SEAN !
Thank you for sharing!
Thank you for sharing this!
This was fantastic
Mr fundamental himself even said that all observations of events in our universe are relative. The answer to the video title can only be subjectively answered within the dimensional and/or classical limitations of the observer who is answering the question. *I'm making a philosophical comment with my internet knowledge of physics*
I really hope his book is a lot like this!
Great discussion, it's a pity the questions are not very audible! (BTW at 33:05 the voice is clearly that of David Wallace)
Understanding how time emerges is the key to it all.... QM and GR are clearly different views of the same thing, only the evolution scale of what’s being measured is orders of magnitude separated, size perhaps doesn’t matter...
Yes on growing your hair out Sean! Looking good
Maybe the unifying principles will relate to some version of entropy / information theory & a logical calculus of information flow.
this is better than sleep 😊
or work
Is that David Wallace at 33:00? Very interesting guy! Saw him on Robert Wright's meaningoflife podcast. Robert Wright I found through Sam Harris, as did I Sean Carroll! CZcams is so great!
Why would the fuzziness of quantum theory automatically guarantee that GR is the fundamental theory?
How can you explain quantum phenomena including the Maxwell's electromagnetism and strong nuclear force using the messy GR tensors?
Sorry, I don't know enough of physics to use sophisticated language.
What is the Ontological Model corresponding to a quantum field theory?
I love how he keeps telling people to buy his book.
There is a evolutionary force becoming apparent in the physics community. As experimental physicists have gotten better at proving or disproving the theoretical physicist's models, the theoretical physicists have gotten better at making models which cannot be tested. LOL
man i sure do love experimental string theory
@@Safwan.Hossain haha
Just out of curiosity, do we know if antimater behaves the same way as matter in a gravitational field? I don't know if the anti-hydrogen factory at CERN contains enough atoms to measure the effect.
It's being tested, but probably. I would think black holes and hawking radiation means it must, but I know nothing.
What is more fundamental, a bit or a transistor? Pen or paper? Colors shapes? Melody or rhythm? One is the actor one is the stage. However I am of the veiw that G.R. is quantized. My intuition is that one can not be derived from the other and a more fundamental theory can have multiple components. I realize intuition is an abominable tool to use in fundamental physics. Best to let these guys sort it out I guess.
How does mass cause gravity? That's the question to answer. The cause of mass is quantum-mechanical (Higgs and strong force) its effects relativistic. Bridging that gap should give the answer. So which theories and, crucially, experiments or observational tests are scheduled or being made already to test this gap, if any?
If we rather suppose that all matter distorts or 'warps' the very essence or fabric of space-time, then the concept of gravity as even being a thing tends to vanish, just like the 'ether' that was once fabricated and concocted as it was thought to be necessary and needed to exist as a medium in order for photons (and thus light) to travel. - j q t -
I always thought QM was more fundamental and that GR was an approximation of an as-of-yet undiscovered quantum gravity
... or space-time is the master field of Quantum Fielf Theory. Nobdy knows yet.
We can not test gravity at quantum level do not mean gravity do not work on quantum level, have some cue from Rydberg constant is function of atom radius R=1/(4*3.14*5.3*10^-11*137)=10973731, compare Planck to proton scale(8.85*10^-16/(1.6*10^35*4.18))^2=1.75*10^38 is ratio of strong to gravity force.
Matthew Leifer and Einstein accept the equivalence of gravity and acceleration. I have been subject to gravity for 80 years. My mass has increased due to sugar, but not due to acceleration. Jupiter's orbit has not noticeably changed due to my mass increase. But had I experienced 1 G acceleration for 80 years (my time) my mass at Earth-Jupiter distance would alter Jupiter's orbit in a noticeable way. So acceleration is fundamentally different from gravity - two different things.
somewhere there in the title should be word "emergent", because its opposite of fundamental and thats what the argument is basically right?
I’m with the wine guy
It will be that both are correct and fundamental they connect with the correct Hubble constant
Great video. But the Sound level is way too LOW. Please do better next time.
Toward the end of Dr. Carroll's introduction, he equates individuals who take consciousness to be fundamental with individuals who take a direct realist approach to experience. I believe this is not totally correct, as many eastern worldviews (Vedanta, some schools of Buddhism, etc...) take consciousness to be fundamental but take the world of experience to be illusory (with respect to the true nature of reality). Incorporating this third view may help in debates such as these.
Donald Hoffman announced this morning that he wants to have a recorded discussion together with Nima Arkani-Hamed. Is that the direction you're thinking of?
Lol, Sean Carroll looks completely toasted in this video. I respect him tremendously and watch all of his videos. This video is a great discussion, and Sean’s face throughout gives added entertainment!
Is this like my football? I enjoy watching the sparring greatly, and I'd like to pretend I know what's going on, although I could never compete myself. Unlike football however I don't really have a team and just wish all involved the best luck at their efforts.
Why is the theory of the world even required? To meet what problem?
"Duality" or "plurality"? But if that is Duality only from the vantage point of the theory itself, then is it really a Duality? If not then of what use is the theory itself? The idea of Knowledge as theory, principle or law is what gives rise to the postulation of Duality
I agree with Carroll on quantum mechanics being more fundamental than relativity, but not because I think his "mad-dog Everettian" (MDE) hypothesis will be the key that unlocks this puzzle. The MWI core belief in the quantum wave function being a complete representation of the entire multiverse requires something like MDE to explain how multiple relativistic spacetime worlds can be derived from a single unified wave function of the universe. The problem as I see it is that the deterministic, complex-valued, infinite-dimensional Configuration Space in which the quantum wave function is defined is fundamentally unlike the non-deterministic, four-dimensional spacetime domain of relativity. Rather than force two mutually-incongruent realms to cohabit the same fundamental theory, why not simply accept Configuration Space as an underlying quantum framework from which the probabilistic trajectories of subatomic particles are projected into relativistic spacetime? Perhaps the reason we've been unable to incorporate gravity into quantum mechanics is because gravity doesn't exist in Configuration Space, that it's really just a curvature of the fabric of spacetime rather than a quantizable force.
If so, the appropriate challenge would be to derive a relativistic modification of Born's Rule, the function that predicts the statistical probability density of particle trajectories in spacetime as their quantum wave function representations evolve according to Schrodinger's equation. This seems like a reasonable approach, since gravity results from the cummulative mass of the statistical distributions of those same particle trajectories. While this would make particle trajectories dependent on the local curvature of spacetime, that seems like a far easier challenge than quantizing gravity at the subatomic level to make it compatible with quantum mechanics.
At 52:00 I didn't catch the funny comment, did anyone else catch it? Thanks!
He's gonna knock that glass of wine over...
Sean looking a bit like Ulrich from the TV series 'Dark' lately.
Waiting for the wine to take a trip across the table...
Please adjust sound levels and reupload. Too good to not hear!
hes pissed up man. this is a pub chat session
Can I come on your podcast
Sean has aged so damn much ever since he was on joe rogans podcast
Yes Quantum Mechanics and Relativity work and have done a great job so far. But do they describe the real picture. I think something very fundamental is missing in our understanding.
Try linking the Higgs field and the strong nuclear force, which create mass, to what we know about the effects of mass (i.e. gravity) via General Relativity. Whoever bridges that gap, pretty much has unified it all.
I'm thinking buckyballs could be a subject of study here: massive enough yet still quantum-ly uncertain.
Is red or green more colorful?
For humans it's green because it stimulates our cone cells much more than red
@@Smitology Does it hurt to be so smart?
Is it me or the audio is very low in volume?
Another great science topic, & a victim of bad & low level sound recording distance...There is something called external microphone...LOL
Why is it so quiet?
Might be worth checking out timecompressiontheory.com it's the closest we have to a unified field theory yet
Sean shut em down with 1:07:27 to 1:08:15, next time boys.
Of coarse quantum mechanics is more fundamental. That said, we still have a lot of work to do in our understanding of these fundamentals.
@Heisenberg-SchrodingerEmc2 It was meant as a joke. A dry joke that likely went unnoticed. Here I was making claims about our fundamental universe while very uneducatedly using the wrong homophone.
Not enough bottles of wine gave up their ghosts in this convo....
Ads CFT says clearly that QM and GR are on an equal footing in this regard.
Can you please explain this? Why is it so?
I think Occam's razor answers this question.
In great detail, I might add.
Watch one man yell while the other one whispers. Impossible to fall asleep to and get anything out of it unless if you don't want to hear half of it or have your ears exploded.
It's a pretty stupid question. The two views (or models) of our reality are brilliant but incomplete. Both have withstood endless testing i.e. have not been falsified so far. There MUST be better questions :0)
Sean= QM, more Fundamental
9:31 = truth
Holy gas bag at 32:00 ish!
they are like Sheldon and Lennard haha
"I wrote a book on it, you can go buy it" hehe always selling, I like.
The final answer is that the concepts of distance and time come from GR and therefore QED/QFT cannot even make rigorous claims about distance and time until it is reconciled with GR - so GR is more fundamental. Anyway - the really really final answer is the 2nd law of thermodynamics. It is very simple to derive GR from the 2nd law of thermodynamics and once you have done that it is simple to derive QED/QFT from GR.
The most generic sense of distance (in 3 dimensions) and time are fundamentally axiomatic. However, it is the 2nd law of thermodynamics that provides a basis to relate them into a mathematical formula as an inverse square law which naturally provides symmetry breaking.
So three dimensions of space and a single dimension of time are necessarily fundamental and when you relate them together as an inverse square law you have the small possible rational "building block" - a building block that is sufficient to construct general relativity (i.e. Lorentz transformations of distance and time). All symmetry breaking arises from this inverse square law given 3 dimensions of space and a single dimension of time.
The result is a basically Newtonian version of General Relativity where the easiest way to understand General Relativity is as transformations of Maxwell's equations. Once you have that small fix for Relativity, then it is super easy to derive both Bose-Einstein Statistics and Fermi-Dirac Statistics.
At that point, you only need a single new transformation (of the Maxwell version of General Relativity) and you get everything you need for a hydrogen atom - the strong and weak forces (really just a special case of EM+GR), the Eigen States of Hydrogen, and the Schrodinger Equation for Hydrogen.
Finally, you only need one more transformation to get a Neutron. Once you have a neutron, then that is enough to describe all of chemistry.
Literally, then there is nothing else except for the 2nd law of thermodynamics (which assumes 3 dimensions of space and a single dimension of time). It is sufficient as a basis to describe all physical phenomenon and thus parsimony dictates that anything not directly described in terms of the 2nd law is less useful/interesting.
It's ok - I think I can clear up the confusion! dS/dt >= 0 implies a homogeneous state without any preference for a specific direction that must evolve over time. Do you agree? I think it is not controversial to assume agreement.
Measurable, change or evolution in a homogeneous state implies isotropic evolution of the change. Thus arises the inverse square law I=P/4 Pi r^2. And indeed this is why you find the entirety of classical physics is driven by thermodynamics and inverse square laws F=Gm1m2/r^2 and F=keq1q2/r^2 and even E=Mc^2 which has its radius obscured in the speed of light. I mean even if you look at the Lorentz transformation for time it is built on an inverse square law t'=γ(t-(vx/c^2)).
The Lorentz transformation for distance though is thought of as a linear function. That is a mistake. People talk about Einstein's mistakes - this is the real mistake. I mean it is a fine approximation for scales above the size of an atom or two, but on smaller scales, it has caused profound confusion.
Do you understand that the entirety of classical physics can be described with inverse square laws or not? You seem to have been able to recognize that gravity and magnetism are inverse square laws.
If you understand these facts, then it defies set theory and the laws of logic to say that a subset has nothing to do with the set.
As for "radial dependence" in the speed of light, I never implied such a thing. However, in the cases I mentioned (the equivalence law and the Lorentz transformation for time) are driven by dynamics that share an inverse square relationship with the distance element of the speed of light. This is just another fact.
My apologies if I haven't described it well enough for you to grock it.
"And evolution in a homogenous state is a contradiction" my apologies for not making my intended meaning more clear. I thought it was clear I was giving the homogeneous state as the starting state upon which some change (an ideal point-source) has occurred and that change then must propagate through the original state isometrically.
"even E=Mc^2 which has its radius obscured in the speed of light." "This is where you explicitly state a radial dependence on the speed of light. Are you lying or did you mean to write something else?"
Incorrect - I merely referenced the fact that the formula for speed is distance/time. Speed squared then is distance squared over time squared. A radius is also a distance. As I mentioned, it was hidden in there.
"Inverse square laws" are only appropriate for potentials ... so no - I understand that the entirety of classical physics CAN'T be described by "inverse square laws".
This is a profoundly incorrect and short-sighted assertion that is contradicted by all known evidence. Kepler, for example, could make the same argument in favor of his model over Newton's, but Newton's model is considered better. Newtons model is better because using a single inverse square law, he/we can describe all the same interactions as Kepler even though in Kepler's model there was no obvious sign of an inverse square law.
For your position to have merit, you would similarly have to show there is some classical phenomenology that either defies gravity, defies Coulomb's law, or posit a new formulation of either one and give evidence your new formulation is more parsimonious than those two well-established models.
"You don't have to apologise for being non-sensical, physics is hard and takes lots of time and effort to get the hang of."
it is quite ok, when you learn the formula for speed, come to understand that all physical forces are merely permutations of the fundamental forces, and learn to embrace parsimony, you will be well on your way to understanding physics.
"Do you know what a potential is? It seems you do not."
This is cute but irrelevant
"My position is that you have not stated a single coherent sentence relating to physics, this far." and yet you now seem to understand the formula for speed. You still seem confused about the difference between Kepler and Newton. If you think that example was incoherent, it explains a lot.
Your arguments have largely been straw-manning, distraction, and arguments from ignorance. These are all logical fallacies. Really though you are not arguing against me, you are arguing against set theory (3rd-grade math) and parsimoney (8th-grade science).
You can't expect anyone to take you serious when you haven't bothered to learn 3rd grade math and you argue against basic logic.
tl:dr - QM wins the mind, GR the heart. You have to turn sound all the way up and some of the participant's questions will still be inaudible, I imagine the small number of down votes are because of that. It is not 75 minutes of lost time.
The reveal for me here was how tightly social norms constrain the physics folk, even with libation, in an actual symposium. Crazy is fine but only within well received channels. That the result can be spun as "hearts" vs "minds" shows the yearning for something more but an unwillingness to go there.
I am pretty sure when Leifer ventures, timidly, and to general amusement that QM would go way before a GUT would be realized what he actually meant was that QCD would go way, i.e. the culmination of QM in the standard model, a theory of unobservable phenomena, that would collapse before GR does, which for the reason in the next paragraph, I agree is the more likely outcome, GR is not a neck stuck out.
Here's the kind of thing you can't say. You can't say that GR is vacuous, just a more accurate description than classical gravitation but with nothing more to really offer in terms of explanation (as opposed to prediction). You can't say that the reification of space and time as actual concrete things, with talk about the creation of one and questioning the reality of the other are absurd. You can't question the basic way physics is done, or rather if you do you are totally on your own. You can't speculate that gravitation suggests that it is a force which brings things which are same underlying thing back together and anti-gravity the so-called dark energy expanding the observable universe. Or more precisely you can do these things but you are then in the unreceived cray cray and on your own.
You are a great reviewer. And I like what you said at the end.
I am very sure that quabtun mecanic it going to prevale over general relativity even does you have work to understand how particule at subatomic level are the faundation of big mass formation and expantion to but it is nice. To delve in into the damention of those subatomic particule puzzeling to find but these great mind like plank nier bohr and many others peter higgs max born and great mind newton with gravity and many others hug evert .but very the important quantun gravitity is to be able to understand how everythings that exit in the universe it came to be
I can't see David Wallace, but I know what his arms are doing.
Fun Fact: These guys are handcuffed at the ankle
Smerk level: God Tier
Sean Carroll is one of my favorite PR Physicists in academia since Feynman But I Don't see how imaginary universes(in whatever form) is more sensible than the rather simple concept of rendering as per ANY VR model.
I think it’s kinda the other way round. By using a non collapsing wave function interpretation, you actually miss a step, from there the maths leads logically to a multiverse....
realcygnus to
SR more important than GR AND QM because it forbid humans from reaching the stars .The nearest star is 2.2 light years away and a round trip would take 4.4 years travelling at the velocity of a photon.Why is this fact being ignored by the nearly all scientists
To Serve Man
Multiverses without many worlds?
Whuhhut?!?
I do some VR programming and to make the rendering of spacetime more efficient I use quaternion math which requires imaginary numbers. You can describe VR using spacetime approximately but if you want better more realistic VR you will need to work with imaginary numbers calculation.
drinking about physics
what does he say funny at 9:42
What kind of wine is that?
Red.
9:39- Got it. Now I don't need to listen to the rest. 👍👍👍
Not sure why a dicy theory can be fundamental 😇
Induction (the form of reasoning) falling
1:06:08-1:06:13
Confused Quantim Mechanic. CQM Theory
Call me a loser but do you think the fast speed we a travailing through space and the fact we then also rotate around a sun has everything to do with us needing sleep... Because the body is not aware we are moving but it might have some kind of impact on us like spinning really fast on a ride and then needing time to not feel sick but instead of being sick we are sleeping... and the fact that we need sleep is to regroup before moving around and oh no i'v gone cross eyed.
El Los er' I have often wondered that if life had developed on a planet with 2 suns then constant daylight would negate the evolutionary advantage which being unconscious during darkness bestows .( avoidance of predation )
Is that Craig Callender being unintelligeble for these physicists with his question? Come on Craig, that's why you're not on these panels! Keep it short and concise
Sean Carroll's brain could smash a thousand Boltzmann brains!
you can tell their highly intellectual in their field because there is a known correlation between super high intellect and inability to setup audio and visual equipment appropriately. I call it the AVminefieldperogitive
Quinn IsHappy omg. As the particle physics department secretary for a national laboratory, I have never ever related to a comment more than this one. I can’t believe someone else understands this :)
Im not saying Sean is wasted, but Sean looks a little bit wasted. Take an uber, Sir!!