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ants_everywhere10/11/20244 repliesview on HN

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 are mathematically interesting and aren't totally understood from a mathematical perspective. But they're different enough that studying them may break the impasse.

I see (1) as largely limited by the budgets and technology needed to build things like particle accelerators and spacecraft.

For (2) you have to decide whether to only explore mathematics that defines physical reality, or whether to also allow exploration of non-physical systems. For example, you might explore a universe that is almost physical but has time machines. Restricting the search space to only physically realistic systems is a significant constraint, so there's a debate to be be had about how much weight to give it.


Replies

ordu10/11/2024

> 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 way that kicked Copernicus to redraw epicycles with the Sun in the center? I mean, is there some notes on these? For example, Newton took as granted that celestial bodies move by elliptical orbits, and somehow he guessed that the gravitation law has r^2 in its denominator, and so he invented calculus to prove, that if you have r^2 in the denominator then you'll get elliptical orbits. The question where Newton got his guess it remains open for me, but back to Copernicus, what was his way?

Maybe he thought how movements of planets will look if seen from the Sun, and so he had redrawn epicycles to take a look, and he got circles? (I'm not sure that it could work this way, I propose this answer to my question just to give an example of the kind of an answer I'd like to have).

I ask this question for two reasons.

1. I believe that Copernicus advanced the science not with surpising physical observation and not with mathematical advances, to me it seems more like surprising mathematical observation. I'm not sure what was that observation exactly.

2. Can one apply techniques of Copernicus to the modern physics? I suspect that it will not. I'm sure physicist already tried everything and there were (is) a lot of them and they are pretty smart people, so it is highly unlikely that Copernicus can help them in any way. But I'm still curious, what Copernicus would do? Would he tried to imagine how electron flying through a double-slit might observe scientists-observers? Or maybe it would try to feel the pain of a black that may believe that the whole universe is falling on it? I bet that the true Copernicus idea would require to use some pretty hard mind-altering substances, and I like such ideas.

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Ma8ee10/11/2024

Those mathematical advances weren't developed in a vacuum, but made to solve some very specific problems which came from better measurements. So even Newtonian mechanics originated in solving problems trying to explain measurements, not that someone sat in their chamber and dreamed up cool math that happened to be very useful.

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throwawaymaths10/12/2024

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)

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slashdave10/11/2024

(1) is also limited by imagination

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