Fundamental physics is dying? [video] • Hacker News Board

Re: Fundamental physics is dying? [video]

#131

Post by lazide » Sat, Oct 12, 2024, 6:16 AM UTC

btilly wrote: post #25

lazide wrote: post #13

Earlier quoted context omitted.

[flagged]

I think that you have half a point. You're absolutely right that just because people are paid to think about things, doesn't mean that they are making progress. And there is a lot of evidence that this is true today in the foundations of physics. However string theory was not intentionally untestable. In https://www.youtube.com/watch?v=eRzQDyw5C3M she gives a good history of why it was originally invented, what testa…

Fair point, I guess. It’s easy to also see how it just mostly ended up there. Still. A problem.

Re: Fundamental physics is dying? [video]

#132

Post by throwawaymaths » Sat, Oct 12, 2024, 6:25 AM UTC

XorNot wrote: post #105

jerf wrote: post #60

Earlier quoted context omitted.

Yes, there's definitely some interesting fields that are making progress that are still in the purview of "physics". Materials science, or condensed matter physics, is doing a lot of fascinating work with quasiparticles: https://en.wikipedia.org/wiki/Quasiparticle There's a number of fields you could call "quantum engineering" where physics and engineering work together on the cutting edge. Some of the output of that…

> Since people on the internet frequently seem to operate on the silly theory that someone pointing out a problem has some sort of obligation to propose a solution The issue with Sabine is she tends to yell about anyone proposing any solution. CERN would like to build a bigger particle accelerator, but since it's not her favored variant of accelerator they are obviously lying to the public and wasting your tax payer…

> CERN would like to build a bigger particle accelerator

Sabine has a point though. There isn't any specific thing thing that a larger accelerator is likely to yield a positive answer on. Unlike the current biggest, which was at least explicitly constructed to find the higgs.

And before you say dark matter, there's zero evidence that dark matter particles will be in any given mass range nor is there a solud model that predicts an interaction that will generate such a particle.

Re: Fundamental physics is dying? [video]

#133

Post by throwawaymaths » Sat, Oct 12, 2024, 6:29 AM UTC

ants_everywhere wrote: post #40

My 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…

Name a single physics phenomenon that was discovered purely with way 2. I can only think of one, the positron.

Newtonian physics was not kicked off by math "advances". Approximately speaking it was the other way, Newton created the math to explain p^2 ~ r^3, which was a surprising observation.

Even theory of relativity wasn't really a math advance, the math was already mostly worked out by mach, lorenz, and minkowski. Einstein put it together into a coherent story (v. Important)

Re: Fundamental physics is dying? [video]

#134

Post by randomNumber7 » Sat, Oct 12, 2024, 6:31 AM UTC

I think the problem is more fundamental. Newtonian mechanics is a science based on observation. Mathematics is just used to build a model that describes _how_ the reality behaves, not why.

Now Einstein is very special, because he proved that our human perception of space and time is wrong. When we think about the allegory of the cave, we got a glimpse of the reality we couldnt see before.

Nowadays every phyiscist wants to be the next einstein that uses mathematics to show us something about reality. The problem is that einstein had good reasons for his ideas. The constant speed of light didn't really work with maxwells equations. The model at that time didn't correctly describe the observations and the maths he used to solve that is rather elegant and simple.

Re: Fundamental physics is dying? [video]

#135

Post by pmontra » Sat, Oct 12, 2024, 6:42 AM UTC

btilly wrote: post #39

ricksunny wrote: post #11

Earlier quoted context omitted.

This is beautifully articulated. And reinforces my general below-the-line (layperson) fear about the state of physics today (as reinforced ofc by the likes of Sabine Hossenfelder & Eric Weinstein).

Thank you for the compliment. I've been working on how to formulate that idea clearly for a while. It is a problem that goes well beyond physics. For example I believe that the same cognitive error is behind the fact that experts do significantly worse than chance in actually predicting the world, and the more certain the expert sounds, the less likely they are to be right. See https://www.amazon.com/Expert-Political…

Given infinite outcomes, experts in a field without a theory of the world that can be used to calculate the future will always perform worse than chance.

Experts of engineering perform better than non experts. However the field of political behavior (or economy) is difficult. The only way to know what's going to happen is wait for it to happen.

Sometimes you know more or less what's going to happen but not the details or the exact outcome. That's enough to make plans.

Examples: at the beginning of 2024 we average persons knew that Putin would win the Russian elections no matter what. We average persons also knew that either Trump or Biden would win the American ones but we didn't know whom. We have to wait. Then surprise, it became either Trump or Harris.

Maybe there are people around the world or even the USA that wonder why Obama don't run for president instead of Harris. They are not experts of the rules of the competition.

So the question is, do the experts predictions are consistently worse than the predictions of any randomly picked person?

Re: Fundamental physics is dying? [video]

#136

Post by randomNumber7 » Sat, Oct 12, 2024, 6:46 AM UTC

btilly wrote: post #4

The 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…

To extend this, group dynamics can come into play too.

I once worked at a startup that developed fancy new tec. The group dynamic there was that critical thinking absolutely did not exist. The reason was probably that they accepted only people in their circle, that had the same burning positive attitude towards the idea.

This can become a self reinforcing circle, because critically thinking people will leave at some point. (Like sabine did in physics).

Re: Fundamental physics is dying? [video]

#137

Post by zburatorul » Sat, Oct 12, 2024, 7:00 AM UTC

throwawaymaths wrote: post #133

ants_everywhere wrote: post #40

My 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…

Name a single physics phenomenon that was discovered purely with way 2. I can only think of one, the positron. Newtonian physics was not kicked off by math "advances". Approximately speaking it was the other way, Newton created the math to explain p^2 ~ r^3, which was a surprising observation. Even theory of relativity wasn't really a math advance, the math was already mostly worked out by mach, lorenz, and minkowski…

The Higgs.

Re: Fundamental physics is dying? [video]

#138

Post by randomNumber7 » Sat, Oct 12, 2024, 7:01 AM UTC

elashri wrote: post #106

I know that this will probably be down-voted to death but I don't like these hyperbolic takes. I know that Sabine did use this title for click-bate purposes that she is now mostly doing YouTube videos (she had horrible experience that unfortunately not rare in scientific community [1]). I understand that the field of particle physics which is the corner stone in fundamental physics is not showing the great advances t…

Seems like you are not downvoted on HN for rational argumentation.

I still think sabine has a point. When we consider occam's razor string theory is absurd. Just because einstein used math to show our perception of the world is flawed, doesn't mean it is likely repeatable with an overly complicated mathematical model.

Yet we live in a world, where highly decorated physicists spin a tale of consciousness beeing enabled by the collapse of the wave function (and other absurd stuff like many world interpretation). This wasted also my time, because it confused me for a while.

Let religion for the religious, philosophy to the philosopher. Physics should be a science based on observation.

Re: Fundamental physics is dying? [video]

#139

Post by btilly » Sat, Oct 12, 2024, 7:21 AM UTC

canjobear wrote: post #122

ordu wrote: post #85

Earlier 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…

I'd say that Galileo spotting the phases of Venus was also a big deal.

Re: Fundamental physics is dying? [video]

#140

Post by btilly » Sat, Oct 12, 2024, 7:28 AM UTC

pmontra wrote: post #135

btilly wrote: post #39

Earlier quoted context omitted.

Thank you for the compliment. I've been working on how to formulate that idea clearly for a while. It is a problem that goes well beyond physics. For example I believe that the same cognitive error is behind the fact that experts do significantly worse than chance in actually predicting the world, and the more certain the expert sounds, the less likely they are to be right. See https://www.amazon.com/Expert-Political…

Given infinite outcomes, experts in a field without a theory of the world that can be used to calculate the future will always perform worse than chance. Experts of engineering perform better than non experts. However the field of political behavior (or economy) is difficult. The only way to know what's going to happen is wait for it to happen. Sometimes you know more or less what's going to happen but not the detail…

Experts who felt certain about their ideas did worse than chance, and worse than simplistic models.

Experts who quantified uncertainty and tried multiple theories did better than both chance or simplistic models.

Sadly, the experts who felt certain presented themselves with confidence and got higher paying jobs.

Normal people were not in the data set reported. He's since done more research on good predictions. You can read Superforecasting by the same author for more.