This was initially a sidebar in a larger post about Hexen arcanophysics and the current state of resurrection magic, but I realized it was far too in-depth to be a functional aside, so I've split it into its own thing. I've recently been having a bit of a STEMgirl renaissance, dusting off my old physics education and catching up on what's new in the inhumanities, and this is me making a post addressing one of my personal bugbears that has been poking at me for years now.
I've heard comparison from multiple people over the years between dark matter and the crystalline spheres hypothesis. A common sentiment I've heard from various people who I respect very much intellectually is that dark matter is probably just the physicists having the math wrong or thinking of the problem in a reasonable but fundamentally flawed way that won't be cracked until some big-brain lady makes the necessary correction. I guess I see the logic, a lot of intractable problems in physics before turned out to be resolved with a big paradigm shift (c.f. relativity, quantum mechanics, etc...).
The problem with this line of thinking, in my opinion, is that physicists do not claim to know what dark matter is, or even that it exists. "Dark matter" means that we have this system of physics called General Relativity, and it's really good, and it solves nearly all large-scale phenomena we plug into it with stunning accuracy, and where it's wrong it can often (usually? I'm hedging my words here but 'usually' sounds about right) be made to agree with observations by inputting extra mass into our equations that cannot presently be observed with telescopes. This mass behaves like mass in most ways, including being found in different densities and quantities in different galaxies like you might expect physical stuff to be, but our telescopes can't see it.
We mostly use light in various forms (including radio, infrared, x-rays, etc...) to look at outer space so the notion that there might be some actual physical stuff there that just does not interact with the electromagnetic force (and by extension photons) is pretty popular just by, like, Occam's Razor, but it's not a conclusive claim anyone is able to make. Particle theories of dark matter are popular because particle physics has been remarkably successful in the past century, and particle colliders have been a very successful, albeit expensive, type of experimental setup which opens the possibility that if dark matter really is some kind of particle we might just be able to make it at home and see what it does, and because GR's failure at the particle scale and the Standard Model's failure at the interstellar scale is an open question in physics that everyone wants to solve. But also, it's important to remember that the Standard Model is largely a theory of very very very small things and General Relativity is a theory of very very very big things, so the disagreements are more of a theoretical problem than a pragmatic one, since their areas of strength don't overlap very much.
So what about the crystal spheres thing? What if the math is just wrong and everyone's barking up the wrong tree? Well, there's physicists who argue that too, and are currently working to try to "correct the math" and find some new formulation of gravity that will account for dark matter without needing to actually posit the existence of extra invisible stuff. The thing is that when someone just says "I bet the physicists are all wrong" on Discord they can just go on with their life, whereas when a physicist says that they have to actually prove it, and unfortunately it turns out that the idea of inventing a new math that explains all our previous results and the "dark matter" observations is very easy to just say aloud and very very difficult to do in a way that stands up to scrutiny. If someone makes a sweeping observation to their friends about the state of the hardest unsolved problems in the field right now they just have to sound right; if you are a physicist making that claim professionally, you actually have to be right.
There are people working their hardest at that, and I wish them the best of luck, but unfortunately they have yet to succeed in a way that outperforms vanilla General Relativity w/ dark matter corrections—they can explain some stuff, but not all the stuff, and to be able to conclusively say you're right rather than just that your research is promising you need to be able to explain everything - or, at least, everything we can already explain with our existing theories. These guys are usually able to make equations to explain observations from like one or two galaxies, and don't get me wrong that's really cool, but nothing close to a working universal theory of gravitation that does away with dark matter has been invented. Maybe something will come up! Who knows! But the people in the field are by and large not chasing that as the most likely possibility, and it's not because of a failure of imagination.
I'd bet my bottom dollar that like half of all working theorists have some wacky personal theory of dark matter that they only ever bring up when deep in their drinks and shooting the shit with friends about the big questions, but they also generally have the good sense not to stake their professional reputations on it unless they have a very good reason to believe it's anything other than a hunch. That's not just them being risk-averse and uncreative and refusing to look out the telescope like Galileo etc..., it's a very reasonable precaution against becoming the next cold fusion guys. People come up with zany ideas all the time, it's just that 90% of them get filtered out once you do the back-of-the-envelope calculations, and 90% of the survivors get filtered out once you realize there's no experimental setup that could possibly test it, and then 90% of those get filtered out when people realize that if they talk too much about it in public they run the risk of Twitter picking up some noncommittal statement about their research and running it into a boom-bust hype cycle with a huge media circus around some big breakthrough that predictably fails to produce any usable results because of a lack of applicable experiment or a failure to replicate.
I probably won't go around posting this on blogrolls and will just keep it in the back pocket for if I ever get into this discussion with someone again. Hope you enjoyed my little science hour :)
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| By ESA/Hubble & NASA; D. Carter (LJMU) Acknowledgement: Nick Rose - http://www.spacetelescope.org/images/potw1402a/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=30673266 |
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