alt Hacker NewsGravity seems holographic. What does that mean for reality?
Comments
This is cool, but I've noticed that an idea of a "holographic universe" makes the news roughly once a decade.
Maybe fifth time's the charm. ;-)
Mathematician, not physicist, but it seems reasonable to me that you could encode a sufficiently constrained 3D space on a 2D boundary. And if you have such an encoding, it also doesn't seem insane that some things might be more easily modeled on the 2D boundary than the 3D space.
If you can convert back and forth between a 2D representation and a 3D representation, and different phenomena are more easily modeled in each, does it matter which is "real"? Unless of course you can come up with a specific prediction and experiment to test it.
I think the box explanation is misleading. There isn't literally a box whose surface you measure. The idea is that the state of a higher-dimensional gravitational system can, in some cases, be completely described by a theory in one fewer dimension.
As a non expert who's just curious about science but also tries to talk like a normal person, from what I can tell holography really seems like it's now the leading candidate to be the next big conceptual revolution in physics.
There's not necessarily any breakthrough right around the corner and we shouldn't rush to coronation preemptively, but there's a lot of physics "voting with their feet" for holography as the article says, and I think it's officially time to start getting hyped. It could have sanity-restoring answers to questions of quantum weirdness, albeit at the rather expensive cost of giving up even more on our day to day intuitions about space and time in favor of an apparently informational substrate.
String theory had a generation of great science communicators writing its books and singing its praises, but holography doesn't yet have equivalent public champions, and I hope that's something that changes sooner than later.
> You can “compress all of the three-dimensional world into two dimensions.”
That sounds a little like the sophons in the novel Three Body Problem. IIRC, aliens took a photon, unfolded it to a flat surface to etch circuitry on, then folded it back up and fired the photon at earth where it unfolded again and did the bidding of the aliens.
> you can decipher the entire contents of the box just by repeatedly measuring points on the surface
So if the box is both inside and outside of a black hole, is that a path for information to leave a black hole?
If 3D space can be packed into a 2D hologram, then, can that 2D data be packed into a 1D hologram and so on?
> “You can ‘compress all of the three-dimensional world into two dimensions.’”
Would this imply that time is the third dimension?
PBS Space Time, could watch it all day, sometimes listen in the background all day
* https://www.youtube.com/watch?v=DoCYY9sa2kU
* https://www.youtube.com/watch?v=klpDHn8viX8
Did some work on this as a self-reported crank. https://helyn.com/constitution-as-colimit
Aside: Quanta magazine always has excellent design & visuals.
This article seems to repeatedly blur the distinction between 'having space' to encode all the states inside a volume on it's surface and an actual theory of correspondence of states.
"Having space" is just a consequence of black holes. If you have more information in a volume than can be encoded on its surface in theory, you have enough mass inside the volume to make it a black hole and the event horizon then has enough space to encode the information even if the original surface did not.
The correspondence between information, thermodynamics, and mass that causes black holes to 'make it possible' to holographically encode all the information inside is what makes this theory so tempting. What if everything is information, and black holes aren't an expression of 'too much mass', but rather just a result of 'too much information to store'. This theory, if it existed, would demonstrate a key result of both relativity and quantum theory based on a very simple premise, and suggests it might then be possible to base both General Relativity and Quantum Theory on top of a simpler theory.
> That’s a violation of logic and geometry. It asks us to erase the categorical difference between square meters and cubic meters.
No, that's sheer nonsense.
> There is no negative mass, so you can always infer the one real arrangement of stuff inside from the warping of space-time at the surface of your box.
Positive mass does not make this argument work. Two bodies in GR can have different distributions of mass but identical exterior geometry. A counterexample is two spherically symmetric, uncharged bodies with the same total gravitational mass but different radial density profiles. By Birkhoff’s theorem, their exterior vacuum geometries are identical.
<Layperson>
Just as acceleration through space causes [the same effect as] gravity, could regular gravity be the movement through TIME?
Could gravity be a facet of time as electricity is to magnetism and vice versa? and the reason we cannot "isolate" gravity is because it's interwoven with time?
But then it would be weird that photos who don't experience time are affected by gravity..
Or maybe space, time and gravity are a trinity?
(no I'm not high, but maybe I should be)
My nitpick is with something the author said in passing about Hawking. Yes, around 1970 Hawking and the scientific community at large still used to believe nothing could escape a black hole, and between 1971 and 1973 Hawking along with Penrose and others expanded their evolving understanding and consequences of of Albert Einstein's breakthrough work.
But then Hawking argued back the opposite case, which in simple terms means that some things can, indeed, escape an event horizon. In fact, name dropping Hawking just to mention his views as they stood before his 1973 work, and his 1974 model of Hawking radiation seems dangerously incomplete journalistic reporting.
In 1974 Hawking formulated what we now know as Hawking Radiation, which is the *exact opposite* of what was previously believed about the impossibility of anything coming back from a black hole. Whilst still not conclusively proven as a physical fact, this did win him the Special Fundamental Physics Prize in 2013. specifically for his discovery of Hawking radiation from black holes and his deep contributions to quantum gravity and quantum aspects of the early universe.
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> Holography implies that you can do that — reconstruct every fold, vessel, and neuron in three dimensions — without actually looking inside. Simply photographing the surface of the brain somehow suffices.
Gah I am not a fan of pop-sci simplifications like this for the sake of a soundbite. The author goes onto explain how no, a picture is not enough, you need to actually measure the distortion of spacetime at the surface. Somebody is going to walk away thinking this stuff is possible, that maybe psychics really can detect something wrong with them.
When I read "But holography really starts to bite only after..." my LLM-dar goes off. Everything I read up to that point was comprehensible, but man, I have developed a shudder reaction to any language suggesting AI was involved ibn its creation.
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Gravity is half spin hyperdimensional vector torsion. I have decided to accept “half spin torsion” as “vortex” and see gravity as the torsion interference along a G <timespace> dimensionality.
There are other dimensionality!
The dimensions are like origami, not parallel universes, however the relationships are as though such (all origami pieces then hyperdimensionality relate.)
If we call the underlying “universal potential” and whatever we think our universe as, is a plane for hyperdimensional coordinates, much of this will begin to make sense.
Gravity (and space time) is a “universal field” that “falls” Around the distributed mass (vector torsions of mass particles) and mass particles are universal potential (same stuff as measured energy in a photon) is half spin vector locked discrete amounts.
Sub-atomic particles may then be discrete spin lock configurations and not distinct in any other way.
This would make the Higgs particle a lie, and the Higgs field this deformation of gravitational surface area.
Just what I’ve come up with. Existential reality (universal potential distributing) is holographic and gravity is half spin vector torsion on a plane of universal existence.
> space maybe an illusion..
space is an illusion...The only thing that is absolute is consciousness, on top of which all illusions stand.
> With gravity, mass plays the role of charge. It bends space-time around it, and it is always positive. There is no negative mass, so you can always infer the one real arrangement of stuff inside from the warping of space-time at the surface of your box.
This is a simplification to the point of just being wrong. Gauss’s law works for gravity; if you put a shell around Earth you have no way of knowing whether it’s a planet or an Earth-mass black hole inside. Assuming spherical symmetry of density, anyway.
Fascinating article... reminds me once again why I went into EE/CS instead of physics, I just wasn't smart enough :-(