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this post was submitted on 18 Mar 2024
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Astronomy
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The whole "dark matter" thing has never sat right with me. It always seemed like a desperate attempt to explain what we see. I'm not saying I know enough to have an informed opinion, but it has always seemed wrong. It is matter we can't detect in any way except for gravity? Nah. The forces of nature changing due to expansion? Fits better somehow. Anyway, what do I know? I entertained the idea that it was time that was changing due to the expansion, but I couldn't get it to fit. This seems more plausible.
That's exactly what Dark Matter is. Scientists saw that galaxies were spinning faster than expected, did some math, and figured out that based on current, known physics, they wouldn't be able to stay together.
So they said "huh, must be additional matter that we can't account for, let's call it Dark Matter for the time being, cause we can't see it." It might be one big type of thing, it might be a thousand smaller types of things that all add up to this collective Dark Matter, but whatever it is, it doesn't behave the same way we expect normal, everyday matter behaves.
Other scientists said that we must not understand something about physics and gravity at larger scales.
Other scientists said that light must not act the way we expect, and it's throwing off our measurements.
Based on follow up research, there is more evidence for unaccounted for matter, than the other options.
It's entirely possible that none of those options are correct, but most of the data we have right now points to Dark Matter is the best fit for the evidence we have.
Excellent summary.
I'm aware we'll never find the bottom truth, whatever that may be, it's only better and better models. Sometimes though, the model chosen by the scientific community isn't really a good one, despite fitting most of the data. I think dark matter, like the aether(spelling?), is one of those models. Again, I base this solely on the clunky, ad hoc feeling of the dark matter model and not of anything more substantial than that. If I'm wrong and they manage to find a chunk of dark matter I'm fine with that. The chunk part was a joke, btw, I'll settle for detection or proof of existence.
When we discover someone we don't understand we often make a simplistic metaphor to fit the data until we have better understanding. Like the Bohr model of the atom, or Newton's theory of gravity. Dark matter plugs the hole right now and does it with a minimum of contrivance (Occam and whatnot)
Or the aether or the flat earth model. I know all this, but I still believe it is a bad and lazy model that stopped a lot of people from trying to find something else that could explain what we're seeing, or not seeing actually. There is too much gravity, yes. What could produce that effect? Shit we aren't seeing, dark matter, sure. But what if there's no 'extra' matter? What other thing could produce the appearance of too much matter? Is time changing in some way we don't know? Is light slowing down/going faster due to the expansion? Is there something else that we thinks is constant that is actually changing over time? Should I really smoke this much? I don't know any of this obviously but I have a distinct feeling we are missing something with 'dark matter' as a model. I get why we use it, but I don't like it. When we create a model, we fix it in our minds and it is very hard to break free from that mindset. Look what it took before we accepted that time is relative. What else is relative? What, besides mass, aren't we seeing?
Of course I'm not the first to think about it and of course I'm not as smart as many, or most of those guys. But if you put up a grand model that's largely unsubstantiated too early and everyone and their dog runs with it, you create a bias to try and prove it and more resources will be added to that than to find alternative explanations that night also fit the data. That is basically my gripe with dark matter as a name for the discrepancy between observable matter and "invisible" matter. It is too ad hoc, mostly added to try and save as much as possible of present understanding of how shit works. Must've stepped on a toe there, chief.
I really shouldn't feed the trolls, but I have to ask - is she hot or is she a used up tramp like your mum?
I too don't really know enough to have an informed opinion, but I don't think "plausible" has much meaning in physics. It's more a question of whether the mathematics supports the theory and/or if it can be proved somehow.
There are plenty of things that the mathematics predicted that seemed completely implausible, but were later verified to be true. "Quantum Entanglement" jumps to mind as something Einstein dismissed as "spooky action at a distance", but it has since been confirmed.
I think you could consider all of physics or even all of science to be made up of placeholders meant to keep things moving until a better explanation comes along.
Yeah, "plausible" was the wrong word to use. Maybe "more elegant"? Then again, the truth (not that there is one, precisely) isn't always elegant.
I agree. I would add that intuition, common sense, and ideologies are also just placeholders in our journey to a better world.
The way I see it, Dark Matter is just a psuedonym for "Whatever is causing gravity to work differently at a galaxy scale than at a solar system scale". And further, Dark Energy is just a term for "Whatever is causing gravity to work differently at an inter-galactic scale than at a intra-galactic scale or solar system scale".
But, if we want to entertain the technical aspects of the thought, there's nothing in the definition of Matter that says it interacts with anything besides gravity (light, magnetism, etc) on its own. Just that it has mass (ie generates gravity) and cant occupy the same space as other mass. We already know via colliders that the higs bosson is the sub-particle solely responsible for Mass, way smaller than the scale of an atom. And we also know that magnetism, electric charge, and by extension light rely on electrons, which exist only at the atomic scale. So its not implausible to think that mass can exist separate from any of the things that we can detect with our other favorite methods (pretty much just different wavelengths of light) besides just the gravity they generate. In this case, gravity IS the thing we're using to detect it.
A few things not quite right here. Particles are given mass through interacting directly with the Higgs field itself. They don’t need the boson to be involved. Due to the way the math works out, the Higgs field has a non-zero value everywhere, so everything that interacts with that field is given mass by that.
Also, we know of weakly interacting matter such as neutrinos that can pass directly through other matter most of the time already. Things can be in the same place as long as the fields they’re part of don’t interact in a way that stops it.
Magnetism, electric charge, and light rely on photons, not electrons. Photons are the bosons of the electromagnetic field. Bosons are called force carriers. They get exchanged any time an electromagnetic force acts on anything. Electrons are a particle and made from the electron field. They are involved in a lot of electromagnetic interactions via photons, but not all of them.
Nothing is. Gravity works the same. We don't just infer dark matter from gravity fields. We can detect and map the exact locations of dark matter thru gravitational lensing.
https://science.nasa.gov/missions/hubble/hubbles-dark-matter-map/