Hacker News new | ask | show | jobs
by zethus 1340 days ago
> The speculative claims discussed in this article have no evidence to support them.

Can you highlight which claims that you find to be speculative without evidence? There's a mix of existing theories that are being actively studied in theoretical physics (holographic cosmology), and some claims that the author seems to call out in rhetorical question. I get that either will whoosh over the lay person.
1 comments
pdonis 1340 days ago
> There's a mix of existing theories that are being actively studied in theoretical physics (holographic cosmology), and some claims that the author seems to call out in rhetorical question.

All of those are speculative claims without evidence to support them.

link
zethus 1340 days ago
I'd argue that in the case of AdS/CFT correspondence, they've been mathematically proven to be _possible_. Doesn't mean that it is true. We also don't have all of the answers to AdS/CFT questions to prove a holographic universe theory with utmost certainty. I would, however, agree that evidence could have been presented in the article, but I'm guessing the target audience for this piece may have never clicked into an array of academic papers.

The classical wormhole as an extreme fold in spacetime is mathematically _possible_, but given what we've observed in the universe, extremely unlikely to naturally occur.

link
pdonis 1340 days ago
"Mathematically possible" is a much lower bar than "has evidence to support it". Yes, AdS/CFT is mathematically consistent, as are classical GR wormhole models. But there is no evidence to support either.

> I would, however, agree that evidence could have been presented in the article, but I'm guessing the target audience for this piece may have never clicked into an array of academic papers.

If you know of any scientific papers that present evidence for AdS/CFT (or for wormholes, for that matter), please post links. I'm not aware of any such papers.

link
zethus 1340 days ago
Ah I understand your argument now and can agree we are on the same page. Can't say I know of any empirical/observed evidence either. I don't believe AdS/CFT can be used to make predictions of precise accuracy beyond serving as a toy model to reshape other physical observation.

To get off the tangent, I've backed up the comment chain and am thinking about your original comments on the harmfulness of articles like this. At first I shared OP's sentiment that it is generally harmless, but the more I think about it, the more I take your stance. Curious what your thoughts are on exposing more people to theoretical physics sans popsci buzzword articles?

For anyone else who's following this thread, I would recommend checking out "The Trouble with Physics" https://www.goodreads.com/book/show/108939.The_Trouble_with_...

link
pdonis 1340 days ago
> Curious what your thoughts are on exposing more people to theoretical physics sans popsci buzzword articles?

It's a great thing to try to do; I try to do it myself as a contributor to Physics Forums [1], for example.

I'm not sure how much good books like The Trouble With Physics actually do as far as exposing more people to physics sans popsci, because, while they might point out issues with how speculative research in physics is done, they don't actually teach any physics.

I personally would recommend Feynman's books for the layman, such as QED: The Strange Theory of Light and Matter or The Character of Physical Law, or Six Easy Pieces (followed by Six Not So Easy Pieces), as ways for people to get at least some exposure to physics without popsci buzzwords. IMO even those books are limited, because you can't really understand physics without actually doing the math and solving some actual problems. But they're still way better than popsci articles (or, for that matter, popsci books like those of Brian Greene or Michio Kaku).

[1] https://www.physicsforums.com

link
jemmyw 1340 days ago
Would also recommend Sabine Hossenfelder for some similar views on the path physics is taking / dangers of popsci https://www.goodreads.com/book/show/36341728-lost-in-math

I've also enjoyed her YouTube videos that have knocked down a lot of my popsci derived thoughts.

link
codethief 1340 days ago
> Yes, AdS/CFT is mathematically consistent, as are classical GR wormhole models

Nitpick (one which I'm sure you are aware of but it might be relevant for other readers): Classical GR (including wormhole spacetimes and others) is mathematically rigorous. All objects are precisely defined and you can write down actual mathematical theorems.

In contrast, AdS/CFT is anything but rigorous. It's basically just lots of handwaving; it's a hunch that people have, based upon lots of mathematically rather non-sensical calculations.

So I wouldn't want to equate the two in terms of rigorosity / consistency.

link