Earlier quoted context omitted.
It predicted supersymmetry, which has been experimentally disproved.
The kind of supersymmetry you’re referring to (global spacetime supersymmetry) is not required by string theory; this is a common misconception. Looking for super partners in a collider is actually only telling you about global supersymmetry, which unlike local supersymmetry is not a universal feature of string theory at low energy, in fact the opposite, it is probably non-generic. It so happens that a class of appea…
Fundamental physics is dying? [video]
151–160 of 245 posts
Re: Fundamental physics is dying? [video]
#152My understanding of the situation (which may be wrong, in which case please let me know) is that physics is stuck at a local optimum. There are two obvious ways to get out (1) Surprising physical observations, or (2) Mathematical advances Way (1) is what kicked off quantum mechanics. Way (2) is what kicked off Newtonian mechanics. I see string theorists and loop quantum gravity people as working on (2). Their models…
> physics is stuck at a local optimum. I think I heard somewhere that the trouble with string theory is it can describe anything if you tune it just in a right way. It reminds me of epicycles, they also had this property, you can add more and more epicycles to describe literally any observation data. > Way (1) is what kicked off quantum mechanics. Way (2) is what kicked off Newtonian mechanics. Hmm... What was the wa…
It’s only really our current understanding of gravity that makes it unobvious.
Re: Fundamental physics is dying? [video]
#153Earlier quoted context omitted.
> physics is stuck at a local optimum. I think I heard somewhere that the trouble with string theory is it can describe anything if you tune it just in a right way. It reminds me of epicycles, they also had this property, you can add more and more epicycles to describe literally any observation data. > Way (1) is what kicked off quantum mechanics. Way (2) is what kicked off Newtonian mechanics. Hmm... What was the wa…
Copernicus used the same circular-orbit-plus-epicycles system as Ptolemy, just the orbits were centered around the sun (kind of---each planet had its own circle, with the sun only approximately in the middle). The system actually had more epicycles than Ptolemy's and was less accurate. It wasn't an advance in any meaningful sense. The real breakthrough was Kepler, who dropped the idea that planets moved in circles. I…
Re: Fundamental physics is dying? [video]
#154Earlier quoted context omitted.
I don't like Sabine Hossenfelder's videos because they're too short. When I want to relax after work by playing a game while listening to someone drone on on youtube on a deep and esoteric subject, her videos end way too soon, and with an advertisement for her sponsor. I just want to hear some rambling boffin expound for an hour in the background on some matter that can't possibly raise more than a few hundred views.…
> When I want to relax after work by playing a game while listening to someone drone on on youtube on a deep and esoteric subject Angela Collier is the answer to your plea.
Like for example, her QCD video was about how explaining QCD to laypersons is impossible. She dunked on Feynman diagrams, first as not being real math, then because its antimatter notation makes laypeople think antimatter is time-reversed matter. ...which it is, iiuc, as far as the calculations of quantum field theory are concerned. Also that QCD is misleading because color charge isn't actual colors, as if viewers are doomed to take the color-wheel analogy literally.
But this is a cynically pessimistic view to have as a science communicator. PBS Spacetime has covered QCD. Feynman's QED book teaches the layperson how diffraction, lensing, magnetic repulsion etc. work in terms of Feynman diagrams he shows you how to work through!
Why not teach science, rather than spread snark? Why not bring the audience up to you, rather than talking down to them?
Re: Fundamental physics is dying? [video]
#155This might be too weird to be true, but when I heard that Geoff Hinton got the Nobel prize for Physics, I wondered if the prize committee was having trouble finding "real" physicists who had made fundamental advances.... This is not meant to knock Prof Hinton. These are his own words: “I’m not a physicist, I have very high respect for physics,” Hinton said. “I dropped out of physics after my first year at university…
Indeed, the online memes about Hinton and Hassabis being "a bit of a myself!" are justified, in my opinion.
Re: Fundamental physics is dying? [video]
#156Re: Fundamental physics is dying? [video]
#157I've said this before in not the same words, and I am always downvoted here on hackernews: people need to understand theory of knowledge before they understand science. Physics and physicists are the worst offenders.
If by "theory of knowledge", you mean they need to have read a bunch of philosophical musings on epistemology, then I strongly agree with the downvoters, because that's utter nonsense. If you mean anything else by that, then you're being way too vague to contribute to a technical discussion, so again I agree with the downvoters. Try defining what you mean by "theory of knowledge" and explain why you think that's requ…
Scientists think they are in the unique possession of tools which ascertain truths - this is misled.
Re: Fundamental physics is dying? [video]
#158I've said this before in not the same words, and I am always downvoted here on hackernews: people need to understand theory of knowledge before they understand science. Physics and physicists are the worst offenders.
Amusingly, the International Baccalaureate Diploma Programma - an A-Levels like uni-prep course - has a subject called TOK: Theory of Knowledge with these intentions.
Re: Fundamental physics is dying? [video]
#159The fundamental reason for this is simple. Humans are prone to cognitive dissonance. Meaning, we do absurd things to avoid painful thoughts. And anything that questions our sense of identity, is a painful thought. So if my self-image is, "I've advanced our understanding of the fundamental nature of reality," then the idea that my contributions weren't useful becomes painful. So we avoid thinking it, challenge people…
> So if my self-image is, "I've advanced our understanding of the fundamental nature of reality," then the idea that my contributions weren't useful becomes painful. Only if one believes the logical fallacy that the dependent steps of a process of elimination weren't useful.
If someone is later in their career and looking at having to throw away all that time - time they will never recover - it takes someone really special to just do it.
And by really special I mean ‘kinda suicidal sometimes’.
Re: Fundamental physics is dying? [video]
#160I've said this before in not the same words, and I am always downvoted here on hackernews: people need to understand theory of knowledge before they understand science. Physics and physicists are the worst offenders.
This strongly depends on what you mean by "theory of knowledge". If you mean the practical importance of self-honesty, and a historical awareness of how easily we slip into self-delusion, then I agree. See, for instance, https://calteches.library.caltech.edu/51/2/CargoCult.htm for a very famous speech on exactly this topic. A lot of Feynman's writing touches on the same issue. If you mean the musings of philosophers…
I'm in the Popper camp on your example. You may have good reasons as to why you say he's wrong, but isn't that the scientific method: showing things to be false. If it can't be shown to be false then how can it be scientific? It might be some other branch of thought.
On the specific case of quantum mechanics - I want to see these forever promised quantum computers actually doing something useful. The promises went from (Vs classical computers) they will do everything faster, to they will do some things faster, to they will do some things not achievable at all. And yet, they still haven't done anything as far as I can tell. Physicists need to answer honestly for this.