Read the full article at Quanta Magazine: www.quantamagazine.org/the-physicist-who-bets-that-gravity-cant-be-quantized-20230710/ Explore similar coverage: www.quantamagazine.org/tag/quantum-gravity/

All we need is a physicist named Oppenheimest and we're set.

This is exactly the kind of thinking that, even if it's proven wrong, in doing so it will have contributed massively toward our understanding of the universe.

Measuring the noise in the gravitational field around a 1kg mass sounds incredibly difficult.

This guy taught my Quantum Computation course a long long time ago (2012). So cool to see him pop up here.

Describing an experiment, whose outcome will restrict the possibilities how the universe fundamentally works, is a big scientific accomplishment.

"What we were able to prove is that any consistent theories of coupling between classical degrees of freedom and quantum degrees of freedom have to be fundamentally stochastic." Huge. So exciting to see what these experiments reveal

Penrose (paraphrased): “The trouble is that we’re trying and trying to quantize gravity, but we really need to gravitize quantum mechanics.”

I have this feeling that gravity is in essence an emergent phenomena, a classical observable and hence, trying to quantize it seems like trying to fit something in a box that doesn't fit. Kudos to him for daring to try this approach.

It’s refreshing to hear a different take on gravity for once

If evidence for noise in gravitational fields is strengthened, it will mean either that 1) gravity may harbor substantial nonquantizable stochasticity; or 2) that we are presently underinformed regarding the abundance and/or energetic states of gravity's discrete units. I'd bet on the latter. Thus far, it sure looks as though the history of physics is that stochasticity is always apparent only until those units are better understood.

I’m a huge fan of turning problems on their heads and it’s pretty much a fundamental tenant of human behaviour that over time (what passes for) knowledge becomes tied up with dogma, which is often confused with strings. Whether ultimately right or wrong this gets a standing o from me on that basis alone.

What catches my attention is the throwing out of the information paradox. The notion that information is some sort of fundamental conserved quantity rather than a human-centric descriptor of what we can know has always rubbed me the wrong way, so to see a hypothesis that just chucks it out the window, at least in part, is refreshing.

I like how there's already tests of this math - I do think gravity will be quantum, but I cannot wait to see what happens here

I hope he defined the 5,000 items better than that, otherwise someone's going to give him 8.3e-21 moles of elemental hydrogen and call it done. They might even try giving him a quarter of that, counting the electron and quarks separately. We can only hope they don't start trying to count the gluons. It'd probably be easier just to radically overpay with a glass of water.

If time is quantized what is the frame rate of the universe.

Does anyone know what the current upper and lower bounds set by those experiments are? Was that the range 10^-1 -> 10^-40 which was being scribbled onto the board in the video

When/where are the experiments happening?

I like this approach. In General Relativity gravity is not even a force. In this approach, locally it is a fictitious force just like Coriolis force or centrifugal force. But we do not quantize fictitious forces. So why should we attempt that with gravity?

when it comes to experimental measurement in the "randomness of gravity", how can we distinguish a random (but classical) gravitational noise from quantum fluctuations stemming from quantum gravity?

Brilliant. I hope you win your bet and I wish I'd had a tutor like you.

If I'm understanding where he's going with this, his experiments sound a lot like a question I've had for a few years. If an electron cloud is just a probability density function, then we should expect its electromagnetic field to be dispersed throughout this cloud (instead of a point-charge all the way down). If gravity is fundamentally quantum, then we have good reason to believe that its gravitational field should be dispersed in the same manner. The only issue is that gravity is extremely weak, so we have to either get creative with how we would measure something like this, or wait until we have technology sensitive enough to make these measurements.

Excellent video, inspiring beyond imagination

To whoever did the edit, the b-roll cut at 5:47 was incredibly satisfying.

If mass depends on the velocity of the particle I figure a kind of descent as a result which attracts in superposition the particles around is quantum gravity. For me clocks tick relativ to the mass as to the velocity of the particles. Does that make any sense?

Beautiful explanation of the black hole information paradox!

Hi thank you for the information. I have some theory about the spacetime which is kind of weird but it could be right and if I am right then so many things changes in science, but I don’t know who to contact please help me not to be wasted. Thanks

What if we can somehow redefine the stress-energy distribution used in GR to determine space time curvature in terms of the probabilities used in QM? In that way, GR can still be the space time "canvas" on which QFT happens, but its curvature is also probabilistic, while events are not points but distributions. My physics in decades back, but I can imagine that Heisenberg could circumvent some singularities here, stuff would pan out for classical scales of action. And I can imagine that the mathematics would be … scary. And if events have no meaning for very small amounts of time or distance, what does that mean for relativity, that is all about events?

Cool and good luck with it, but wondering how you know the noise is not just measurement error?

Random is that which cannot be predicted. So even if something were deterministic, it ramains random as long as you cannot measure it accurately. So basically as long as we dont know everything there will be randomness. And if the universe has true randomness in any form, we cannot know everything.

Oh I'm excited to watch this after work or during lunch break. Let's goooooooo

Is there any more work being done to show how magnetic fields and gravitational fields behave similarly?

What a strangely beautiful idea. It will be fascinating to see what experiments show regarding it.

Does the amount of randomness remain the same or change over time?

"If you don't find randomness and noise in a gravitational field, then you can rule out a classical theory of gravity." That's wrong. In these circumstances, failure to find something is NOT proof that it's not there. It could mean simply that the effect is one decimal point smaller than the sensitivity of your instruments.

"We need to quantize because that’s how we do everything else" Brilliant ontology

Noise in signal processing, say, is the difference between the signal that's being measured minus a quantity that's correlated to the measured signal. In other words, the signal plus the noise is the maximum power of the signal. So -- assuming this applies to the definition of gravity -- what is the maximum measurable quantity of gravity?

The smalest quantum wave is a pair of virtual particles recombining with an other pair. To simpify think of two row of perl neclace. The perls recombine with its neighbouring antiparticle. That edg dislocation (similar to movenent of atom in a metal under stress) is a quantum wave. That is the bending of space time.

How will you differentiate between gravitational noise and noise from experimental uncertainty?

He might be Oppenheim, but Robert was Oppenheimer.

This looks very promising and quite convincing too

The explanation for the origin of structure in the universe in the standard model of cosmology is via the quantum fluctuations of a field that includes part of the gravitational field. I think it will be a struggle to explain the same data (specifically the spectral index of the matter power spectrum) in a model where gravity is fundamentally non-quantum.

I thought time is an evolved property of quantum world. Say in a place where quantum particle needs to do a lot of interactions, those interactions slow things down, so the n+1 interaction takes longer than it would in free space. Thus, time appears to flow slow in densely populated regions of interaction as time is just a measure of rate of change.

Any relation to Irwin Oppenheim (Chemistry-MIT), by any chance?

How do you get a continuous stress energy deformation out of quantized lumps of mass/energy

Interesting. This is my intuition too, which is that "time" does not really "exist" like physical matter does. Rather it is purely a mathematical property that emerges as a derivative of motion and geometry of particles/waves governed by quantum mechanics and electromagnetism. So it seems intuitive that a such a derivative, untethered by the requirements of physicality could just as well be modeled as a continuous function. Looking forward the the experiments!

Great video!!

Only a particle physicist could consider a gold atom to be a “massive object”.

Its like there's this pot that grows and grows as we go around the table making bets. Some having folded, some doubling down. Considering the location of the table i think the safest strategy would be to have an empty open mind. We're probably all too full of ourselves by now to be objective

Lover of this chanell. ❤❤ From Bangladesh.🇧🇩🇧🇩

2:18 The inverse square rate of gravity's effect on the flow rate of time prevents any absolute 0 though doesn't it?

This kinda feels like giving up (on the idea of a Theory of Everything). Then again I suppose science has always been about giving up on pleasing ideas in favor of more accurate ones. Plenty of people didn't like Kepler's science of planetary motion simply cos ellipses feel less 'perfect' than circles, and yet the ellipses turned out to be right. Even the Earth isn't a perfect sphere, annoying as that is to find out.

Very interesting idea but I am confused as to how the stochastic manifests in this theory? Is it that when one tries to couple quantum and classical theories there is a necessary noise in the classical field which results in a stochastic radiation profile for Hawking radiation?

Why would the matter radiating from a black hole be random ? Could it not be previous matter from long ago getting ejected as new matter feeds the black hole ? The transformation of that matter could then be described, assuming we ever figure out the process it undergoes within the celestial body

I love that this is being discussed

Good job guys keep it up.

Best explanation for entanglement in matter, and a cyclic universe, is to allow cold temperatures to geometrically enhance retro-reflection of gravity spin information flows, so please continue selling the idea that entanglement has nothing to do with quantized gravitational energy as well as with long distances or with a light speed increase due to cold-focused gravity flows, that is the ticket to continued fame and fortune with advanced extradimensional wormholery firmly founded upon supreme intercontinental royal colonial word-based technology. Actually, it looks like gravitational information flows depend on the sub-nucleonic reflective geometric nature of the source, even for molecular sources. So much shared state resonance and environmental diversity for GR to brilliantly ignore. Roughly diamond-shaped Bennu and Ryugu both offer retro-reflective flow clues there, maybe??? I'd suggest thinking about it, hard. Gravitational induction (frame drag) without matter radiating and exchanging "virtual" particles of gravitational kinetic spin information between nuclei across any space, even regardless of distance, requires a non-trackable information-pasteurizing classical middleman that is overdue for elimination. Spin induction seems more cosmologically influential in forming sheets and filaments of matter than dark sector experts want to admit. I mean maybe, just maybe, solid temperatures matter very deeply with gravity? Like, I don't know ... increasing temperatures strongly resembles inflating configurations of flattened quarks in baryons? Crazy, right, chaps? Pure abstract non-hyper-dimensional whack-a-doodlery, I mean. Someone doesn't know their gravity place in hyperspace. Massive quarks in different pebbles coordinating on something? Remote pairings of uncanny mirror-like spinning plate actions? Concentrated gravity maybe generates an effective vacuum light speed increase? Eh?? Duh. Retroreflectors are known attention attractors, with pulls or pushes both equal and opposite. So very Hebbian in appearance too. Yet other forms of pseudo-intelligence may forever remain firmly uninterested, absorbed with various creatively dark matters. Another wrinkle - this one concentric - gravity could carry intrinsic quantum galactic rate longitudinal spin reflected in ubiquitous placid-flat galactic size clustering along with characteristic concentric darkly mass-minimized rings where that stationary resulting wavelength is merely classical proton size upscaled by the 10^+36th force-ratio of "virtual" electric and gravity carriers between the particles over non-nuclear distances. Something similarly quantum could easily be forming dark rings dividing up galactic cluster parts, as if the two halves of the "bullet cluster" can spin together. There is a sharp picture of cold super-flat super-large Malin 1 that is just so rippled. It's just another dimensionless number concept where gravity is just another force, like Dirac suggested for cosmological horizons of electron effects with his own misguided "Large Numbers Hypotheses" before galaxies not confused with nebulae were known. Despite all the hype, deSitter space is likely not serious in addition to being too "local" (read as: too "flat lightspeedish" not to mention lacking in reflective focus and so being basically lame), neither is anti-deSitter space.

I believe the black hole information paradox already has a proposed quantum solution that uses replica wormholes.

a deterministic model can contain stochastic processes/models. The converse fails. You lose information in QM and as a result, deterministic statements are no longer possible. I.e., determinism make the better model in principle, but because we are unable to measure anything perfectly we have to introduce statistical mech to make testable predictions.

Awesome idea, shocked I've never seen this proposed. I am just a layman but I consume a ton of physics content and I've never heard this idea mentioned.

I think you will win that bet, maybe not in your lifetime, yet a win. I too think space(time?) cannot be quantized. I put time in parentheses with a question mark as I think time is a quantity associated with energy/mass objects that both operate on space as space operates on energy/mass. Though I think we understand energy/mass objects much more than the space they occupy. I think of space as a quantum less field which seems to limit photons and other electro-magnetic systems to a correlated speed from any frame of reference. (c) Einstein had shown that space deforms when subjected to energy/mass on many ranges. This "tells" the energy/mass how to move within it. Today we are trying to detect those deformations on a smaller scale than blackhole or neutron star mergers. Sort of like an accordions push and pull as space deforms those objects. And it seems that even on the larger scale the movement of those deformations have the same "C" limit as photons etc. While there maybe universes outside of ours, I do not believe that any decision forks in the road create new universes as some physicists suggest either. Even as we gather more information and knowledge, we are far from any "theory of everything". In each lifetime of a person that works in the field, we are standing on the shoulders of those who came and went before us.

Excellent video, even for laymen like myself it was well explained and interesting. If we do indeed live in a simulation, then Gravity is just a rule set being used by the computer to create an evolving 3d world..maybe we are so bogged down in this reality and its simulated laws of physics, ie rulesets, we don't see what's really behind it all...Just computational illusions presented to us in order to experience this reality in a meaningful way and to allow our perceived universe to even exist. Quantum entanglement isn't about separated objects being entangled even over huge distances and disobey the law of nothing can travel fester than light, in reality those two particles are no more real than a perceived 3d tennis game being played out on a 2d screen, everything is just digitised information, even gravity!

Ramp up the mass and amplify the sophistication and precision of The Cavendish Experiment. Introduce random perturbations into the apparatus and then look to see if there is any significance in the variable noise in the outcomes.

Is this part of a larger documentary?

So what about a particle in a superposition is it's gravitational effect not in a superposition?

Think of them as subduction zones for the cosmos

Muy interesante, cambiar la perspectiva de cómo se observa “Los gravitones, la energía de la masa oscura del universo, (la mezcla entre la fuerza de la gravedad con la emergía nuclear; transmutadas por el burbujeó de espuma cuántica del horizonte de sucesos del borde de un agujero negro); transformarse en una especie de gravedad cuántica, dirigida a membranas de diferentes dimensiones.

Great content, but the hyper editing (scene change every 1.5 seconds) and constant music make it a bit too much.

We know that frequency vibrates towards the weakest point of resistance, which is the greater mass of neutralized resistance. Time is the distance traveled in occupational space as mass. Aging or decay is determined by resistance to forward maximum momentum velocity in resistance. Conservation of maximum momentum velocity in resistance in and out of entanglement of mass is constant. Spheres are proof of equalization of pressure in resistance. Energy of thermaldynamics is redirected trajectories reducing distances according to their cycling circulation patterns as mass. As mass decays, distance increases. Space vibrates from resistance to thermaldynamics. Repulsion to propulsion from repulsion. Perpetual motion. Cold resistance of space itself and thermaldynamics coexist as space itself. Cold resistance expands thermaldynamics outward force into weight or density. Density can't exceed resistance within it. Occupational space is neutralized resistance within mass.

The effects of gravity are indistinguishable from the effects of acceleration and the equivalence principle says that there is no way to tell the difference between these two situations by using only local measurements... but, we can say that acceleration and gravity are related by the curvature of space-time. Acceleration can be quantum in nature, in the sense that it can be influenced by quantum mechanical effects such as uncertainty, interference, and tunneling (Bremsstrahlung radiation, Zeeman effect and maybe Schwinger effect) So basically, in order to find the nature and the truth about gravity, we have to understand why the two phonemes are so similar!

I'm not a physicist, but from everything I read it seems pretty convincing that the universe we can physically observe (basically down to the atomic scale) is an incomplete picture. Whether it's a projection from a higher dimension, or there are some forces or particles we don't know about yet, or it's a simulation, or some god-like thing, whatever... and once we figure it out it will either completely break or substantially change all existing theories and even mathematics. I mean, consider all the loop holes in gravitational theory (explained by dark matter nobody confirmed exists), black holes, the existence of reality itself... all things that cannot be explained just by looking at the surface and observing.

On a quantum level, surely time must be changeable. Otherwise how was I able to see a bullet that had been fired at me (on two occasions) and watch it slowly coming towards me, so I could step out of the way?

I suspect at one point in time we are going to find out gravity is, after all, a classical emergent "feature" and not quantifiable..

I feel like Professor Openhimer is trying to bypass Space-Time altogether and pushing it to the background. I'm no physicist. But I bet resolving this issue need going deep into the relationship between Quantization and Space-Time, and more importantly, the very nature of quantization itself. Why we see quantization in the first place, from where wave-particle duality comes from etc.

I doubt they can make background EMF quiet enough to dectect such minute gravitational noise. Technically speaking virtual particles popping in and outnof existence should create gravity. Insofar as the gold blob is concerned we already know matter has a wave function. I think were the gap is not that we live in a quantum world where things are inherently quantized, only the transitions in energy are quantized becauase that transition occurs through the absorption of quanta.

Listening to this physicist talk about his theory: Breathtaking.

There are two clocks - atomic clocks, and gravitational (orbital) clocks. Do they measure the same thing?

Intuition has taken us far and, for many, it still points to quantum gravity. We have been able to quantize everything else with great success; it makes perfect sense to explore that possibility. But if quantum mechanics has taught us anything, I think it is that physics can and will defy our intuitions. I am glad Oppenheim is exploring the potentially unintuitive.

No physical clock can be constructed which can measure time in a continuous fashion, since all the components of any physical device must ultimately be described quantum mechanically. Thus time, as measured in any physical laboratory, will automatically be quantized in character. Injection of noise into a field will not change this, unless the noise precisely models the effects which would have otherwise resulted from quantizing time. [ps Recently published ‘double slit’ experiments support a quantized interpretation of time.]

I love such topics

All we have to do is assume there is a maximum density. What other discrepancies are there?

This way of exploring such a boring physics experiment in such an enthralling and entertaining way, i love it!

This fella has some papers in quantum information that are really good. I like his idea because it's a proposal with an experimental test in mind unlike all of the string theory guys and big unification guys, which never propose experiments at all.

What if gravity is not a force, it's an effect? So you can't quantize it like another force. What's if an effect of something we haven't studied, or figured a set of relations for yet? What if the equations we have for gravity, while seemingly accurate to many degrees of precision, are just an approximation, in the same way that temperature is an emergent property quantized particle kinetics, temperature is an approximation, what if gravity is an approximation that arises out of something more fundamental, that we haven't started picking at yet? If you look far enough out, and far enough back, doesn't gravity start to break down? Isn't that why we need to invoke dark matter and energy, to explain, or rather, to correct the approximation that is gravity?

While watching the video I thought for a second what gravitational field will produce the massive cube with a mass of 100 of Sun. Will it be spherical or cubical in time-space?

We need to go back to r² and the Inverse Square Law of gravitational and EM fields. Could the outward momentum of light form the potential for the inward motion of gravity? The spontaneous absorption and emission of light photon ∆E=hf energy is forming potential photon energy into the kinetic energy of electrons. Kinetic Eₖ=½mv² energy is the energy of what is actually happening. An uncertain probabilistic future is continuously coming into existence with the exchange of photon energy.

It would be interesting to hear what the experimentalists say about this.

Can someone explain why these videos are so interesting to me even though i don't understand most of what is said?

Sounds a bit like Penrose's approach, of an objective collapse of the wavefunction due to gravity.

1:38 ... 2:16 ... you're essentially quantizing the speed of time, [yes, the quantum is INS ( = 0 )! And the clock stopped, so it doesn't make any sense.]

As Tesla once said, 'If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.'" Quantum gravity is simply the sum of the effects of quantum magnetism, which themselves are influenced by waves and vibrations from the other dimensions. In a way, the magnetic effect is one that "draws in" more than it gives out, creating gravity. We are always, in some dimension or other, subjected to a wave pattern.

I know he is more humble than the average professor because of how many times he said “Me and my students”. Most of them are like “me and my giant ego”

That got dark at the end there

Answer the question why the concentration of energy or mass draws in surrounding quantum fields and you have a theory of gravity. Standing on earth it’s like standing in a river as the water flows past us, the water being quantum fields. Just standing still, we experience time dilation. We also experience force. Floating in the river is like freefall - no force. But with our feet on the ground and the river/quantum fields flowing through us, we must experience force on our feet to hold us in place

Measuring noise un a weak field approximation. Hmmm ,idk

I gather the outcome of the bet will be random then...I suppose the result might be randomly consistent with determinism or deterministically consistent with an apparent pseudo random description of Reality. I am quite curious to know what is the criteria to distinguish pseudo randomness from true randomness in the world. One more leap into Metaphysical "languaging" in the fantastical world of Theoretical Physics...

Already explained what the fifth dimension is. In this negative space one can also understand quantum entanglement.

Hello from Kazakhstan. If we add NEW 50% of the Michelson-Morley experiment, then it is “possible” to prove the postulates: 1. Light is an ordered vibration of gravitational quanta. 2. Dominant gravitational fields affect the speed of light in a vacuum, its direction and frequency of oscillations. I need help co-creating an invention. The light in the device has a path of 9000 meters in a volume of 0.4/0.4/0.4 meters.

Hi, how about the Geometric Chronon Field theory? Physical events live in an embedding spacetime and the probability of each event unlike Causal Sets non-locally sums to 1 on the embedding spacetime. Matter occurs where these events are misaligned. This misalignment is measured by the acceleration of the gradient of scalar fields. One scalar field is the the Robert Geroch time function and 3 others have integral curves in the perpendicular foliation. The measurement of this non-geodesic acceleration is by a non-zero generalization of Reeb fields. The Reeb field in its original formalism was not limited to contact manifolds. See "Electro-gravity via geometric chronon field and on the origin of mass" in ResearchGate. This version is much more correct and advanced than the peer reviewed paper from 2017 that had several errors. It is just a model, not a TOE but it may interest you. Please do not forget that manmade models are not reality. They are minimal language predictive models which are a result of our structure which we impose on the shared experience we call "the physical world". Physics is way too much overhyped because some physicists do not have the courage to say the truth. I hope you are one who admits the truth. If you are then we can collaborate. BTW, the application, Hermann Bondi's inertial/gravitational dipole has two partners, my wife and Mr. Raviv Yatom.

Just by watching this I'm struggling to see how this work isn't just semiclassical theory - as in, you know, the kind of math Hawking used to figure out his radiation in the '70s? What's different, here? Am I supposed to look up some arXiv papers just to figure out as much?