Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why the foundations of physics have not progressed for 40 years

iai.tv

Post reply on HN
Print view View original

141–150 of 326 posts

Re: Why the foundations of physics have not progressed for 40 years

#141

Post by brutt »

tlb wrote: post #133
brummm wrote: post #91

Earlier quoted context omitted.

There is no believing in them. Gravitational waves have been observed and you can't "believe" or "not believe" in them anymore than you can "believe" or "not believe" in electricity.

The observations are still subject to debate. The signals are far below the noise and can only be discerned with fancy statistics, which some groups have failed to reproduce. See Hossenfelder's detailed critique at https://backreaction.blogspot.com/2019/09/whats-up-with-ligo...

This video is better, IMHO (same author):

Have we really measured gravitational waves?

https://www.youtube.com/watch?v=WWTvNlfkvoI

Re: Why the foundations of physics have not progressed for 40 years

#142

Post by tlb »

rpz wrote: post #35

In the spirit of pointing out inconsistencies...I am not a physicist, but something I've been confused about lately is why the action constant has a unit of seconds baked into it. Feels like E = hf is an experiment with a hard coded 1 second measure time. Why not express the relationship in terms of power? P=uf where u is the action constant without the seconds unit hard coded. And E=utf has a variable time parameter

h (Planck's constant) has units J*s, and f (frequency) has units 1/s. Therefore E=hf has units of Joules. E is the energy of a single photon at that frequency. It's not a measurement of power.

Re: Why the foundations of physics have not progressed for 40 years

#143

Post by TheOtherHobbes »

peebz wrote: post #29
peignoir wrote: post #21

And academia is failing too, I can’t remember what Nobel prize mentioned that he could not get one today as most researchers are stuck in having to produce papers for the sake of keeping their grants. What would be needed is a lot of free time and freedom to think ...

It was Peter Higgs who said that ( https://www.theguardian.com/science/2013/dec/06/peter-higgs-... ).

This is a much bigger issue. Research has been distorted by irrelevant bureaucratic productivity metrics. So the illusion of regular activity is rewarded, while anyone who takes ten years to explore a truly original ground-breaking idea is punished and excluded.

Re: Why the foundations of physics have not progressed for 40 years

#144

Post by pdonis »

danharaj wrote: post #132
cambalache wrote: post #127

Earlier quoted context omitted.

This is so general and vague that it is useless, even more considering that the author has been saying the same for the last 10 years (the same timeframe her career progression stopped) and there is not a single valuable paper proposing a somewhat-valuable idea. I hate to sound like Lubos Motl (for the cognoscenti) but Sabine's criticism is trite.

It's not general and vague if you're a practicing physicist and know what those inconsistencies are. For example, the Standard Model assumes neutrinos don't have mass, but they do.

> the Standard Model assumes neutrinos don't have mass

No, it doesn't. The original Standard Model from the 1970s did, but then neutrino masses were discovered and the Standard Model was modified to include them.

Re: Why the foundations of physics have not progressed for 40 years

#146

Post by SiempreViernes »

nonbel wrote: post #83
SiempreViernes wrote: post #74

Earlier quoted context omitted.

Actually, Hossenfelders great fight has been with the concept of "naturalness", a fight that has now been won by the LHC killing off all the theories based on that concept. And it wasn't ever so simple as "chasing mathematical elegance instead of trying to explain observations", the problem has been that there was a theory that could explain almost perfectly everything within a certain region of physics, but can't ea…

>"the problem has been that there was a theory that could explain almost perfectly everything within a certain region of physics, but can't easily be extended." Sounds a lot like overfitting.

If that’s what it sounds like then that is a failure of my description: the problem is nothing at all like overfitting, and casting it in that light would be pointless.

Re: Why the foundations of physics have not progressed for 40 years

#147

Post by adrianN »

Anon84 wrote: post #108
throwlaplace wrote: post #102

Earlier quoted context omitted.

that's because experiment drives physics rather than mathematical consistency (no matter how much people pretend it's about "beauty"). plenty of mathematically consistent physical theories have been falsified by experiment and plenty of mathematically inconsistent physical theories have made precise and accurate predictions.

When was the last time an experiment had a result that wasn’t explained by theory (supralumimal neutrinos aside)?

Superconduction is still poorly understood. We don't have a good model that predicts what materials are superconductors.

Re: Why the foundations of physics have not progressed for 40 years

#148

Post by gus_massa »

j1vms wrote: post #137

The role of this "era" may be in reformulating quantum physics and, separately, general relativity in new ways that make the ideas more accessible to more people, and earlier in their lives. The goal could be to make of modern physics... the new classical physics. That is, we start to let go the crutches we still teach because it is thought that day-to-day life is more readily explained by Newtonian physics. We are n…

These theories have a very precise mathematical formulation and very weird unintuitive consequences. If you try to teach them without math, you only keep the weird unintuitive part and it's more unintelligible.

For quantum mechanics you have to know eigenvalues and eigenvectors. This is studies in the first years of the university in a technical career. I'm not sure if it can be teach much earlier.

For Special Relativity you have to know Minkowsky spaces. It's not so difficult, it can be moved to the first years of the university.

For General Relativity you have to know curved spaces. It's not imposible to learn, but you can get a Ph.D. in Math or Physics without studding curved spaces.

Re: Why the foundations of physics have not progressed for 40 years

#149

Post by SiempreViernes »

jjmorrison wrote: post #77
SiempreViernes wrote: post #71

Personally I find it amusing Hossenfelder is now invoking the need for learning philosophy of science, given how hostile she's been to it before. See for instance http://backreaction.blogspot.com/2016/08/the-unbearable-ligh... that begins with: "Philosophy isn’t useful for practicing physicists. On that, I am with Steven Weinberg and Lawrence Krauss who have expressed similar opinions." Though to be fair, she clarifi…

I thought the article was not great. But the fact that she's changed her mind on the topic makes me like her a lot more. How can we learn more if we don't change our mind?

I wasn’t very convinced by the 2016 text either, but the point is more that she’s gone from that clearly stated position to mentioning the importance of ”philosophy of science” in her attacks on current practice without much evidence (that is, not writing about it) that there has been any shift of conviction.

It looks more like Hossenfelder found something discarded in the shed and temporarily use it as a club in want of something better. A slight intellectual dsihonesty.

Re: Why the foundations of physics have not progressed for 40 years

#150

Post by armatav »

wallace_f wrote: post #40
armatav wrote: post #30

Earlier quoted context omitted.

I don’t think physics operates on anything resembling a social-justice system - nothing like the parent comment is going to send us backwards any amount of time in the field, but an attitude that bars commentary might stagnate us for a long time.

>I don’t think physics operates on anything resembling a social-justice system Physicists are chosen within the Academic-Governmental Complex, and as such physicists are chosen according to its preferences. Maybe this is a big problem? It's not just with respect to selection based on gender, race or socioeconomics. Have you read Paul Graham's Lesson to Unlearn, about the adverse incentives and maligned merits which a…

You aren’t getting my position - results drive the field, whether those results come from a tenured professor and his team of PhD students, or some kid in his garage with no formal training.

Physicists are not “chosen”. They are built and trained.

There’s no conspiracy here.

Post reply on HN