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Comment by geijoenr | Hacker News Reader

For some time already we are in an "epicyclean phase" of physics, trapped by the extraordinary predictive success of Quantum Electrodynamics and still using mathematical methods devised in the 19th century (variational calculus). This has lead us to the current situation, with extremely complicated theories at the limit of human understanding that bear no new results. It will take a modern day Copernicus to come up with a new view of physics, that will result in simpler, more productive models, to take us out of the local maximum we are in.

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That makes the assumption that there exists a simpler view of physics that will result in more productivity.

IMO, some of the smartest people that have ever lived, live right now. Mainly because we have more humans alive than ever before. The amount of brain power working to find these simpler models is breath taking, yet we aren't seeing the elegant simple solutions fall out like we once did. I don't think that's a problem with the ingenuity, I think that's a problem with the problem.

If the brain power is focused in the "wrong" direction or all the smart people are constantly looking under the same set of "street lamps" it doesn't matter how many there are. Unconventional thinking is hard you can't force it solely with numbers arguably quite to the contrary: a large agglomeration of scientists can systematically enforce a proportionally larger conformity pressure.

It is a hard balance to strike because on the one hand you want to be constantly challenged by your fellow scientists but on the other hand also just take the foolish liberty to fully develop your (most likely flawed) intuition.

So even if I'm highly sceptical of Wolfram he gets my full respect and also Hugh Everett [0] who wrote a letter to Einstein as a 12-year old with Einstein answering: Dear Hugh: There is no such thing like an irresistible force and immovable body. But there seems to be a very stubborn boy who has forced his way victoriously through strange difficulties created by himself for this purpose. Sincerely yours, A. Einstein And later in life courageously confronted Nils Bohr with the [...] idea that the universe is describable, in theory, by an objectively existing universal wave function (which does not "collapse") i.e. Many-Worlds-Interpretation.

[0]https://en.m.wikipedia.org/wiki/Hugh_Everett_III

I think it's easy to underestimate the extent to which the greatest minds have also turned to every weird permutation you could think of. Personally I figure we'll probably find some deeper theory just since the Standard Model still has its issues and gravity isn't rolled in yet, but there's every reason to think that this problem is hard, not just untried. Much of the most interesting work in the last century has been ruling things out.

There are lots of nifty ideas that are explored until insurmountable holes are found in them. The two main nonstandard lines of thought that have had any real progress are decoherence, which I'd call a success, and string theory, which I'll avoid rating because I have string-theorist friends but am not a liar. There are plenty of others, and maybe one will bear fruit, but honestly when the next big break comes it'll probably be really obvious.

Why would you assume it would be obvious? Copernicus's heliocentric model was wrong in many ways: he assumed uninform speed, that the sun was the center of the universe, that orbits were circular, assumed the necessity of epicycles, and so on. His main victory was simply that from our perspective of complete knowledge we can now safely say he was less-wrong than the geocentric theories of the time; there's also the David vs Goliath narrative which is emotionally satisfying.

If one wanted to cast doubt upon, if not "debunk", his idea from the science of the times, it would not have been difficult to do so (see: Tycho Brahe). And that was on an issue that was likely some orders of magnitude less complex than the one we may be facing today. The implication of that being that the "right" answer may initially seem to have more holes than swiss cheese. I think it's very safe to say that relativity, undoubtedly the monolith to which all scientists aspire, was an exception and not the rule in the march of discovery, in its reception/clarity.

Good point. I guess all the great minds of this time see occupied with how to maximise ad clicks.

Copernicus' model had the planets orbiting the same in circles at uniform speed. This does not match reality, so Copernicus just chucked in some epicycles to correct the error. Copernicus's model had all the complexity of epicycles, but he hard coded the first epicycle into the system by having the planets orbit the Sun instead of the Earth.

We wouldn't need a Copernicus to solve this problem, we would need a Copernicus, then a Kepler, (ellipses & non-uniform speed) then a Newton, (gravity causes ellipses and non-uniform speed) and then an Einstein. (gravity is warping of space-time)

If quantum field theory is as wrong as Ptolemy's geocentric model was, we're hopeless. Because QFT very well predicts the observations; our observations have no ellipses in them that invalidate circular orbits, our observations have no anomalous Mercury precession that invalidates Newtonian gravity, no speed of light being consistent in all directions to invalidate luminiferous aether. To say that we simply need a smarter theoretical physicist is simply wrong -- our current theories do not contradict the things we are able to observe.

We know that general relativity and quantum mechanics do not play nice at small scales and high local gravity. But we cannot observe this conflict. And that's nothing to go on.

We would need an observation which shows that general relativity or QFT is wrong about something before we could conceivably make foundational progress on making new or different theories. And every few months there's a new article about "Einstein is proven right again" or "LHC experiment shows all readings are nominal".

So what is dark matter?

This thing that keeps galaxies bound that we cannot see but can only observe the effects… I think the hunt for it will push us into new territory.

That being said, as you say there has been nothing yet found that violates GR/QFT.

The leading candidate for dark matter is that it's a soup of particles that interact gravitationally, but not via the electromagnic or strong nuclear force. If we're very, very lucky, it might interact via the weak nuclear force, which means there exists a slim theoretically possibility that we might be able to observe it interacting via the weak nuclear force. That being said, even if it does interact via the weak nuclear force, there's nothing to say it doesn't interact in a way which gives us the power to differentiate it from, say, neutrinos. And if it doesn't interact via the weak nuclear force, then we cannot every make any characterizations of it ever, not even with arbitrarily advanced technology.

If that's true we're hosed. There would be no insights, no way to theory ourselves out of it. Only nerds wailing futilely about dark matter on the internet. And sadness. And we wouldn't know it's because all our theories are correct, but we don't have the complete picture of the extra-Standard Model dark matter particles, or if it's because some variation of MOND is true, (although it's extremely unlikely to be a MOND variation) or if we're as wrong as epicycles vs curved fabric of spacetime.

It seems like I'm more hopeful for a quantum explanation of relativity than you are, but it's still sort of disquieting to think that there could be any number of fields that we just couldn't ever properly interact with. Even with gravity rolled in, there could still be a field that just doesn't interact at all. Hell, there could be hundreds. Creepy.

More likely, the symmetries that hide these fields would break down at energies that are way too high to ever reproduce in an accellerator or another lab experiment.

Wouldn't arbitrarily advanced technology be able to move it around with gravity or sense collections of it with some kind of LIGO but with gamma rays for even more precision or something?

Arbitrarily advanced is pretty strong in a world where some people think dyson sphere scale stuff could be real.

You could characterize it gravity-wise, but we can already characterize it gravity-wise (sort of). We really only care about a field to the extent it can interact with other fields, and as of now gravity isn't really a quantum field, but a distinct thing. I think most people hope to eventually get relativity under the quantum umbrella, but we're nowhere near that yet. If relativity is just a description of the stage the other fields dance on, then we're just kinda screwed. We could determine the mass of the particle (assuming we could ever be confident in separate particles at all), but no other properties.

It will take a modern day Copernicus

We might already have a modern day Copernicus. Could be string theory, could be something else. The problem is that we don't really have any experimental data that can't be explained by the Standard Model. What we really need is a modern day Galileo that can perform some sort of observations, like finding Jupiter's moons, that don't fit in with the existing conventional physics.

Could the would-be modern-day Copernicii be being stymied by modern-day academic funding structures and grant review committees?

I also have this impression. I think the current system lacks intellectual diversity. Lots of people pursuing the same few popular lines of inquiry, because if they get away from the herd, they have a hard time joining a big research group, getting funds and getting more people to read and cite their papers.

That problem is kind of inherent in the domain. In the past, significant research could be done with the meager stipends from generous nobles. Cutting-edge physics labs and supercomputers for astrophysical simulations are significantly more expensive.

27% of the universe is totally unknown (dark matter) and another 68% is totally unknown (dark energy), leaving only 5% of our universe that is explained by the standard model.

Feels very epicycle-ish and ripe for a major shift.

they are both called dark for a reason

not very observable

Their effects are observable by way of their gravity.

That's very forgiving.

We have a model and weer have observations. The two don't match, so there is a problem with at least one (model or observations). MOND posits the problem is with the model and proposes refined models. These are refutable and indeed, counterevidence is often found.

Dark matter posits the problem is worth observations. Its solution is to propose a tiny particle that is basically invisible. For every situation, you then can invent an amount and a distribution of these tiny, invisible, undetectable particles to match observations and thereby substantiate your theory.

It's not really surprising that so far, folks have succeeded in inventing a distribution of undetectable clouds of particles, clouds weighing in at multiples of the solar system's combined mass.

Only an undergraduate in Physics, but rest assured that there are many smart minds currently in search of this! Building bigger particle colliders is not the only solution, and there are a lot of interesting things being done with e.g. neutrino physics that may bear fruit in contradicting the standard model.

> we don't really have any experimental data that can't be explained by the Standard Model

What was the evidence Copernicus saw that epicycles didn't explain? (Honest question.)

Nothing. His model actually fit the data worse than epicycles. He just thought it was a more sensible approach that matched the Pythagorean opinion.

It wasn’t until Kepler that a geocentric model involving ellipses actually was more predictive.

Might be worth returning to the Pythagorean interpretation (which Bohr discussed): All is number. The world is made of math, not stuff.

> It wasn’t until Kepler that a geocentric model involving ellipses actually was more predictive.

You mean heliocentric?

Thanks, my bad.

Hmm, a new kind of science.

Wolfram has a proposal, by that very name.

Hasn't yet made useful predictions though.

Due to the mixed reviews, I haven't bothered to read

   https://en.wikipedia.org/wiki/A_New_Kind_of_Science

even though I assume that the target audience is more or less people who were fascinated with

   https://en.wikipedia.org/wiki/Chaos:_Making_a_New_Science

I read this humongous damn thing around 2004. It's not worth it.

Are more modern information-theoretic and dynamical models not used for quantum mechanics? They're both relatively recent and extremely innovative mathematical models.

Granted, I'm not mathematically fluent enough to know if they represent a deviation from variational calculus!

There is constructor theory

https://www.youtube.com/watch?v=hYc97J2MZIo

They are, and you see them used sometimes (my friend is actually using something like that in her thesis), but for the Grand Theory type stuff it seems like this blog is talking about they aren't as useful. They reduce to the same math as before, and on a fundamental enough level the shortcuts they let you take just aren't useful.

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