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Comment by glenstein | Hacker News Reader

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.

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> String theory had a generation of great science communicators writing its books and singing its praises...

I would argue that has done more harm than good. Strong media personalities shouting "the next big breakthrough is here!" followed by 25 years of zero practical results have not done good things for public perception of field of physics. A layperson could be mistaken for assuming the field is literally regressing.

> could be mistaken

Could be forgiven?

Yes, thanks!

Damnit, I rewrote that sentence twice and still got it wrong.

You could be mistaken for that

I don't think the distinction between holography and string theory is as clean as you're making it. The vague idea of holography predates string theory, but most of the working examples we have of holography come from string theory. That's what AdS/CFT is: It's an explicitly holographic description of superstring theory in an anti-Desitter space. It's frankly bizarre that the author of this article doesn't mention that fact. I suspect we are seeing a popular science rebranding of string theory without the word strings.

I didn't intend to assert a clean distinction, you're exactly right about its connection to string theory. What I mean is that String Theory Writ Large enjoyed a lot of popular esteem in the 00s and 2010s in public communication as being our potential new framework for what lies beneath the quantum world, but string theory is huge in and of itself.

It's more a difference of emphasis (holography in particular) than something that's outside the scope of string theory.

I can't tell if you're aware that the holographic principle came from string theory

I can't tell if you're aware that they're not synonyms.

Well the reason I couldn't tell if you were aware is because they aren't synonyms and your comment is perfectly reasonable, but I picked up an (incorrect, it seems) vibe that you thought they were unrelated. Which, they kind of are! It's a fairly interesting story how it came about as a property of string theory but appears to be leaving it behind.

I recommend growing your charitable interpretation muscle, it heads off avoidable confusions like these :)

isn't holographic universe a similar concept to string theory in that they both propose higher dimensions projecting into lower dimensions

string theory, 11 dimensions, is bonkers though, it's what happens when people are too smart for their own good imho lol

No string theory (10d) or m theory (11d) map to lower dimensions (eg 4d) via (generalisation of) Kaluza Klein compactification. Vector boson (eg maxwell or Yang mills) are internal degree la of freedom-> 6/7d graviton becomes a photon/ gluon.

There’s holography in string theory: AdS/CFT but this rather maps 4d super Yang mills (on the boundary of AdS5) in an AdS5xS5 background: which is one holography correspondence we know works.

Holography is much more common, but we only really understand it on hyperbolic spaces.

Also since it has a theory at strong coupling on one side we cannot really do calculation on that side and verify it.

You can use it tho to make calculations.

Many concepts can be framed as projections onto lower dimensions. It’s the specific ways in which things are projected that makes things string theory. IOW don’t mistake the concept of a map for the territory that one type of map describes.

Eh, 11 dimensions is just what the math predicts based on the theory’s postulate and observations of the universe.

Holographic gravity is no less fanciful if there’s no practical experiment to prove it.

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