[brilliantcode]

Can someone explain in layman's terms what really is dark matter and why there's so much obsession around it? If we can't observe it and we are only relying on inferences to explain it's effects, that seems like pretty weak set of legs.

Obviously I'm missing the academic discipline to appreciate this topic but nevertheless, I'm curious about our understanding of the very fabric and mechanisms of our reality and the universe.

[Avshalom]

So basically there are four forces: weak and strong nuclear forces; gravity and EM.

EM is mediated by photons and visible matter is constantly absorbing and emitting photons.

Some particles don't though. Neutrinos for instance. They're dark, they don't interact with light.

So when observation showed that there needs to be more matter laying around than we could see some enterprising young turks said "hey, maybe there's a shit ton of dark matter" and that makes the math come out right.

the obsession is mostly because people who aren't astronomers seem to think "dark" is a metaphor and go "aha now that no one cares about the oxford comma this will be my new opinion"

Up for debate is what kind of particles make up the dark matter and how much mass is dark vs just poor measurements and/or some tweaks to gravity, but unless some one manages to disprove neutrinos: dark matter exists.

[thejollysin]

"Dark Matter" is a phrase we use to describe a hole in our understanding of the universe. To put it simply, when we look out into space, at very large scales like galaxies, everything is just too heavy. It appears as if there is a LOT more matter out there than we can see. Things are orbiting faster than they should be, like galaxies are heavier than makes good sense..

Maybe there is some matter out there that is "dark", so we just can't see it. That would be a solution. Or maybe the laws of gravity we wrote down are bad at large scales. No one knows. Trust no one who tells you they know the answer: if they did they would have a Nobel Prize.

[misnome]

Where "Dark" literally means: does not interact in any way with light