[sigmoid10]

>In holographic theories, physicists may have traced the pliability of space-time to its quantum roots

...ah yes holography again. Not to say that all these insights from it are completely worthless, but unless we actually find a holographic dual of our universe instead of AdS spaces (which are the opposite of our universe if anything), this whole field is starting to feel more like a jobs program for mathematicians out of new ideas.

[zmgsabst]

Also, if all you have is a dual model, then it’s equally accurate to say entanglement arises from spacetime. Eg, this article describes entanglement giving rise to wormholes, but the model equally says wormholes give rise to entanglement.

They’re promoting their preferred frame to ontological status when you can’t use a dual model to assert more than equivalence between frames.

[sigmoid10]

Welcome to modern theoretical physics. This stuff has been going on for more than a quarter of a century now. Yes, AdS/CFT was super cool when it first came out. Just like String Theory was. But both have produced nothing that people had originally hoped for. Just endless mathematical intricacies that are further and further removed from our real universe. The best that came out was some mathematical tooling for adjacent fields that had little to do with understanding the fundamental rules of the universe.

[vbezhenar]

That's how science always worked. The stupid people throw money at smart people and sometimes they pay back with good things. Any attempts to optimize that is futile, so the best we can do is to continue throwing money.

[sigmoid10]

Unfortunately that is not how it works in capitalist societies, because the smart people will eventually figure out how to siphon the maximum amount of money out of the government regardless of the results. Or do you think we should also keep throwing money at Boeing because there are still a few smart engineers left and we might get a worthwhile Starliner and SLS eventually it we just keep throwing money?

[stevenalowe]

Thanks for this - holography as a theory strikes me as an absurd math trick - if a 3d world is really just a 2d surface, would it not logically follow that said 2d surface is itself merely a projection from 1d, and perhaps that is a projection from 0d?

Obviously I don’t understand this, and probably won’t but what limits the dimension reduction?

Going the other way, would our 3d space not be the “surface” of a deeper 4d space, and that of a 5d space, etc?

[dwroberts]

> this whole field is starting to feel more like a jobs program for mathematicians out of new ideas.

So sick of seeing phrases like this.

Science is not business. It is not about producing results that you personally think are important. It is understanding the nature of the universe for the sake of it.

[tsimionescu]

Science and math are not the same thing, though. The concern is that physics, a science, has been sliding too much into math research - specifically talking about the foundations of particle physics.

That is, the concern is that instead of studying the real world, theoretical physicists are spending more and more time studying mathematical constructs and their properties.

[an0malous]

> It is not about producing results that you personally think are important. It is understanding the nature of the universe for the sake of it.

Is this actually stated somewhere by the institutions that take taxpayer money for this research, or just your opinion?

[dwroberts]

If you’re talking about taxpayer money and you’re in the United States, maybe a better starting point is the ‘jobs program’ they’re running for military personnel

[zchrykng]

Please enlighten us how purely theoretical mathematical constructs, that are impossible to test, help us understand anything about our universe.

[Erem]

Imaginary numbers are purely theoretical, but they turn out very helpful in almost every engineering discipline

[sigmoid10]

Imaginary numbers are a helpful tool for calculating things in our universe. All these holographic theories and their insights are based on a universe that behaves basically opposite to ours.

[Erem]

From Wikipedia, imaginary numbers...

> Originally coined in the 17th century by René Descartes[4] as a derogatory term and regarded as fictitious or useless, the concept gained wide acceptance following the work of Leonhard Euler in the 18th century, and Augustin-Louis Cauchy and Carl Friedrich Gauss in the early 19th century.

I think the jury is still out wrt utility of AdS spaces. They could be useless toys, or they could be in the Descartes phase rn.

[zchrykng]

Sure, let me know when any of these imaginary physics is useful for predicting anything that can be observed.

[Erem]

Not a physicist, but I think this paper used holographic principles to predict the minimum ratio of shear viscosity to volume density of entropy in fluids https://arxiv.org/pdf/hep-th/0405231

[dwroberts]

Lots of science is impossible to test practically for hundreds of years before it is actually experimentally verified

[zchrykng]

Not actually science until you can test it.

[echelon]

There's a lot of ire for string theory. It's non-testable and wound up attracting lots of minds, funding, and resources. It hasn't seemingly led to any tangible results. Many scientists express anger about it and claim entire generations of progress were lost.