9 ms·
It's basically the opposite situation from 150 years ago. Back then, we thought our theory was more or less complete while having experimental data which dispr
by bananaflag 9mo ago
It's basically the opposite situation from 150 years ago.
Back then, we thought our theory was more or less complete while having experimental data which disproved it (Michelson-Morley experiment, Mercury perihelion, I am sure there are others).
Right now, we know our theories are incomplete (since GR and QFT are incompatible) while having no experimental data which contradicts them.
- Paracompact 9mo agoWhat about underexplained cosmological epicycles like dark matter (in explaining long-standing divergences of gravitational theory from observation), or the Hubble tension?
- XorNot 9mo agoThis is your regular reminder that epicycles were not an incorrect theory addition until an alternative hypothesis could explain the same behavior without requiring them.
- Paracompact 9mo agoSure, but in that regard dark matter is even more unsatisfying than (contemporary) epicycles, because not only does it add extra complexity, it doesn't even characterize the source of that complexity beyond its gravitational effects.
- cozzyd 9mo agoEven better, there are the "nightmare" scenarios where dark matter can only interact gravitationally with Standard Model particles.
- Paracompact 9mo agoPersonally—and this is where I expect to lose the materialists that I imagine predominate HN—I think we are already in a nightmare scenario with regard to another area: the science of consciousness. The following seem likely to me: (1) Consciousness exists, and is not an illusion that doesn't need explaining (a la Daniel Dennett), nor does it drop out of some magical part of physical theory we've somehow overlooked until now; (2) Mind-matter interactions do not exist, that is, purely physical phenomena can be perfectly explained by appeals to purely physical theories. Such are the stakes of "naturalistic dualist" thinkers like David Chalmers. But if this is the case, it implies that the physics of matter and the physics of consciousness are orthogonal to each other. Much like it would be a nightmare to stipulate that dark matter is a purely gravitational interaction and that's that, it would be a nightmare to stipulate that consciousness and qualia arise noninteractionally from certain physical processes just because. And if there is at least one materially noninteracting orthogonal component to our universe, what if there are more that we can't even perceive?
- im3w1l 9mo agoI've thought about this possibility but come to reject it. If mind-matter interactions did not exist, then matter could not detect the presence of mind. And if the brain cannot detect the mind then we wouldn't be able to talk or write about the mind.
- meindnoch 9mo agoOr, the mind is in spectator mode?
- skeptic_ai 9mo agoFrom a physics point of view should be as every effect is caused by previous state. And next tick is always next tick, except quantum bacause has some randomness, but let’s assume it’s a seeded randomness. I think every tick is predictable from previous state. Inevitable. Therefore I really like how you put it: mind is just spectating.
- dataflow 9mo agoFYI, very recently (as in this has been in the news the past few days, and the article is from December) an article was published that suggested we might already have experimental evidence for dark matter being primordial black holes, though there are reasons to doubt it as well. I just posted the article: https://news.ycombinator.com/item?id=46955545 https://news.ycombinator.com/item?id=46955545 But this might be easier to read: https://www.space.com/astronomy/black-holes/did-astronomers-see-a-black-hole-explode-an-impossible-particle-that-hit-earth-in-2023-may-tell-us https://www.space.com/astronomy/black-holes/did-astronomers-...
- deleted 9mo ago[deleted]
- suddenlybananas 9mo agoScientific theories are not curve-fitting.
- joe_the_user 9mo agoThe dark matter theory broadly is that there is amount of invisible matter that obeys the laws of Einsteinian gravity but isn't otherwise visible. By itself, it has considerable experimental evidence. It doesn't resemble Ptolemaic theories of planetary motion notably in that doesn't and hasn't required regular updating as new data arrives. It really fits well with the OP comments. Nothing really contradicts the theory but there's no deeper theory beyond it. Another comment mentioned as "nightmare" of dark matter only have gravitational interaction with other matter. That would be very unsatisfying for physicists but wouldn't something that really disprove any given theory.
- geysersam 9mo agoWhen you say dark matter theory doesn't require updates when new data arrives, it sounds like you don't count the parameters that describe the dark matter distribution to be part of the theory.
- klipt 9mo agoDoesn't that imply our theories are "good enough" for all practical purposes? If they're impossible to empirically disprove?
- PlatoIsADisease 9mo agoIf I have to make a guess, we are at the level of pre-copernicus in particle physics. We are finding local maximums(induction) but the establishment cannot handle deduction. Everything is an overly complex bandaid. At some point someone will find something elegant that can predict 70% as good, and at some point we will realize: 'Oh that's great, the sun is actually at the center of the solar system, Copernicious was slightly wrong thinking planets make circular rotations. We just needed to use ellipses!' But with particles.
- davrosthedalek 9mo agoThe sun is not at the center of the solar system. The intellectual leap was not to replace earth with the sun. Earth does not "revolve around the sun". The intellectual leap was to realize that the situation is somewhat symmetric -- they both attract each other, and they orbit around their center of gravity (which, yes, is in the sun. But not because the sun is the center.) This sounds like a distinction without consequence, but I think that's wrong. The sun is not special. It just has a lot of mass. If somebody learns: The earth orbits the sun-- They don't understand how two black holes can orbit each other. If somebody learns: The sun and the earth orbit their CM -- They will be able to understand that.
- doctoboggan 9mo agoThe theories don't answer all the questions we can ask, namely questions about how gravity behaves at the quantum scale. (These questions pop up when exploring extremely dense regions of space - the very early universe and black holes).
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- light_triad 9mo ago
- throw_m239339 9mo agoI find the idea that reality might be quantized fascinating, so that all information that exists could be stored in a storage medium big enough. It's also kind of interesting how causality allegedly has a speed limit and it's rather slow all things considered. Anyway, in 150 years we absolutely came a long way, we'll figure it that out eventually, but as always, figuring it out might lead even bigger questions and mysteries...
- csomar 9mo agoIf reality is quantized, how can you store all the information out there without creating a real simulation? (Essentially cloning the environment you want stored)
- tsimionescu 9mo agoNote that "reality" is not quantized in any existing theory. Even in QM/QFT, only certain properties are quantized, such as mass or charge. Others, like position or time, are very much not quantized - the distance between two objects can very well be 2.5pi planck lengths. And not only are they not quantized, the math of these theories does not work if you try to discretize space or time or other properties.
- cvoss 9mo ago> all information that exists could be stored in a storage medium big enough Why is quantization necessary for information storage? If you're speculating about a storage device external to our universe, it need not be constrained by any of our physical laws and their consequences, such as by being made up of finitely many atoms or whatever. It might have components like arbitrary precision real number registers. And if you're speculating about a storage device that lives within our universe, you have a contradiction because it's maximum information capacity can't exceed the information content of its own description.
- atakan_gurkan 9mo agoI disagree, but maybe only because we are using different definitions. For example, we have neutrino oscillations, this requires neutrino mass, which is not part of the standard model of particle physics. In cosmology, there is "lithium problem" (amongst others), which cannot be explained by Lambda-CDM. We know our physical theories are incomplete not only because our mathematical frameworks (GR & QFT) are incompatible (similar to the incompatibility of Maxwell's equations and the Galilean transformations that form the basis of Newtonian mechanics), but also there are these unexplained phenomena, much like the blackbody radiation at the turn of previous century.
- T-A 9mo ago> neutrino mass, which is not part of the standard model of particle physics This is getting tiresome... https://news.ycombinator.com/item?id=46956197 https://news.ycombinator.com/item?id=46956197
- Sniffnoy 9mo agoI wouldn't say that we have no experimental data which contradicts them. Rather, we do have experimental data which contradicts them, but no experimental data that points us in the direction of a solution (and whenever we go looking for the latter, we fail). Consider e.g. neutrino masses. We have plenty of experimental data indicating that neutrinos oscillate and therefore have mass. This poses a problem for the standard model (because there are problems unless the mass comes from the Higgs mechanism, but in the standard model neutrinos can't participate in the Higgs mechanism due to always being left-handed). But whenever we do experiments to attempt to verify one of the ways of fixing this problem -- are there separate right-handed neutrinos we didn't know about, or maybe instead the right-handed neutrinos were just antineutrinos all along? -- we turn up nothing.
- T-A 9mo ago> the standard model neutrinos can't participate in the Higgs mechanism due to always being left-handed This again? It's only true if you insist on sticking with the original form of Weinberg's "model of leptons" from 1967 [1], which was written when massless neutrinos were consistent with available experimental data. Adding quark-style (i.e. Dirac) neutrino mass terms to the Standard Model is a trivial exercise. If doing so offends some prejudice of yours that right-handed neutrino can not exist because they have no electric and weak charge (in which case you must really hate photons too, not to mention gravity) you can resort to a Majorana mass term [2] instead. That question (are neutrinos Dirac or Majorana?) is not a "contradiction", it's an uncertainty caused by how difficult it is to experimentally rule out either option. It is most certainly not "a problem for the standard model". [1] https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.19.1264 https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.19.1264 [2] https://en.wikipedia.org/wiki/Majorana_equation#Mass_term https://en.wikipedia.org/wiki/Majorana_equation#Mass_term
- TheOtherHobbes 9mo agoIt's trivial to add a matrix to account for neutrino masses, but that doesn't explain their origin. That is not a trivial problem at all. It certainly has not been solved, and it's possible experiments will say "Both the current ideas are wrong."
- KolibriFly 9mo agoThis era might be one where we have to earn the next clue much more slowly
- tim333 9mo ago>GR and QFT are incompatible I did physics at uni and kind of dropped out when it got too hard. I've long guessed the incompatibility is because the maths is just too hard for human brains, though I'm probably biased there, and we'll get a breakthrough when AI can handle much more complex maths than us. Probably not so long till we find out on that one. I once tried to write a simplified explanation for why a spin-2 quantum theory naturally results in something like general relativity and totally failed - man that stuff's hard.
- jfengel 9mo agoThe math is hard, but I don't think that's the problem. Hard math eventually succumbs. I think that even if AI were to find a good unification of GR and QM, we wouldn't be able to test it. We might accept it without additional confirmation if it were sufficiently natural-feeling (the way we accepted Newtonian gravity long before we could measure G), but there's no guarantee that we'd ever be able to meaningfully test it. We could get lucky -- such a theory might point at a solution to some of the few loose threads we get out of existing collider and cosmological measurements -- but we might not. We could be stuck wishing we had a galaxy-sized collider.
- tim333 9mo agoIt might explain some of the many physics observations that we don't have explanations for like why do we have the particles we have and why those properties.