There's no dark matter, only dimension flattening weapons being fired at each other by advanced aliens.
Astronomy
hogwash
Man, lots of people in this thread seem happy to accept any wild, physics-breaking idea rather than accept that there's just a bunch of matter we can't see.
I think it goes beyond not being able to "see" it and goes to we can't detect it at all. Doesn't dark matter just fill in the mathemagical holes with some numbers to make it all work?
you can also sort of directly see it with certain colliding galaxies
We can indirectly detect dark matter thru gravitational lensing. That is how NASA created this map showing the actual locations of dark matter in tinted blue.
https://science.nasa.gov/missions/hubble/hubbles-dark-matter-map/
That's a cool one!
Dark matter is matter that we infir to exist only on its gravitational effects. We've observed its existence by the fact that it seems to clump up in the middle of two massive super-solar structures following a collision.
We can detect its gravitational influence, as it interacts via gravity. The issue being that gravity is a weak force, and so there's a lot of room for speculation.
But there is a lot of evidence backing up dark matter existing. But it's not definitive yet.
I get that but it still sounds woo-woo since we can't directly detect it. I'm not naysaying since I realize it's the best we have and I'm not smart enough to come up with anything better.
I mean, I guess it depends on what you mean by "directly detect". We measure neutrinos by having photoreceptors in huge tanks of very pure water deep under old salt mines... which hardly seems more direct than looking at where galaxies and stars are moving and calculating the gravitational pull and noticing that something is missing.....
The Covarying Coupling Constants theory posits that the fundamental constants of nature,[...], are not fixed but vary across the cosmos.
This undermines current fundamental axiom of science that laws of physics are constant across universe. Until we go there and measure them to be actually different. This hypothesis doesn't have a leg to stand on.
I'm skeptical of this theory as well, but I'd point out that our observations show that at galaxy scales, gravity is much stronger in certain places than we'd predict using our current model of gravity and the matter we can otherwise detect, and at even larger scales the acceleration of the universe's expansion is being driven by something we don't understand.
Right now, the dominant theory in cosmology is that each of these observed phenomena are driven by dark matter and dark energy, but we don't have any direct evidence of the existence of either, just indirect evidence that stuff doesn't behave as we might expect.
So it's a choice between theories that don't make intuitive sense, and break some fundamental assumptions about physics.
Tired light makes a lot of sense to me 🥱
IANAP, but isn't universal expansion understood to be accelerating? How would "weakening forces of nature" account for that? Assuming this energy could be "lost" (breaking an even longer standing and well tested principle of physics), that loss wouldn't accelerate anything. At best the speed would remain neutral.
The tired light theory is an alternative explanation to the red shift of distant light that says it's not because distant objects are all moving away from us but instead that the light somehow loses energy as it travels, which lowers its frequency.
There was another alternate theory that suggested everything was shrinking instead of the universe expanding (thus wavelengths seem longer by the time they get to us).
Personally, I'm more "open to the idea" than "sold" for the idea of the universe's accelerated expansion. I like theories that eliminate the need for dark matter or energy, especially given that the current ones requiring them assume that they make up 95% of everything. It just seems more likely that we don't understand things as well as we do than to assume we're right about everything we think but just need to add 19 times what's already here to balance it all out.