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I also have almost no knowledge about dark matter in physics, and maybe I am a complete moron. But what do you think is more likely, there is this matter out th

I also have almost no knowledge about dark matter in physics, and maybe I am a complete moron. But what do you think is more likely, there is this matter out there that no one has been able to find in decades of searching, or the mainstream assumptions/math on gravity are wrong/incomplete? I am going with the later.

mr_mitm 5y ago
It's interesting that this sentiment almost exclusively comes from people with almost no knowledge about dark matter. What do you think is more likely, there is a theory that makes all observations look exactly like there is invisible matter without actually being invisible matter, or that there is invisible matter? I am going with the latter. I also do not understand why laypeople are of the opinion that all massive particles must interact electromagnetically. If you are open to the idea that there is a massive particle that doesn't, you got dark matter.
jug 5y ago
MOND theories etc. like this has fallen kind of out of favor because it’s just so hard to adapt our theory of gravity to resolve this. It’s surprising how often this topic pops up. I think it’s based on a misjudgment that simply missing something in gravity follows Occams Razor better but it actually seems to be the opposite. I think the killer is that dark matter seems to not just hold galaxies together (given their “too high” rotational speeds), but also clump together, and also sometimes be missing in galaxies and other times overwhelm galaxies. It’s super hard to adapt the well proven theory of gravity to especially localized phenomena.
pdonis 5y ago
> what do you think is more likely, there is this matter out there that no one has been able to find in decades of searching, or the mainstream assumptions/math on gravity are wrong/incomplete? You are mis-stating the real issue here. The distribution of matter is already a free parameter in our current theory of gravity, General Relativity. GR in no way requires that all matter be visible to humans. The "no one has been able to find" thing is not a problem for GR, it's a problem for the Standard Model of particle physics, which does not contain any particles that dark matter could be made out of. But most physicists already believe that there are more kinds of particles than the SM describes, we just haven't figured out how to make them in accelerators so we can study them in a controlled experimental fashion, and we haven't figured out any "smoking gun" signature that will tell us if such particles exist out there in the universe. "Dark matter" is really just a name for those kinds of particles that are already believed to exist anyway, we just can't detect them with the technology we currently have. But the technology we currently have is very limited. So the real question you should be asking is, what do you think is more likely, that there are particles that aren't included in the Standard Model of particle physics--which is already believed to be the case anyway--or that General Relativity is wrong in its description of the dynamics of galaxies, even though this is a domain in which GR has already passed stringent experimental tests with predictions accurate to many decimal places? I'm going with the former.

mr_mitm 5y ago

It's interesting that this sentiment almost exclusively comes from people with almost no knowledge about dark matter. What do you think is more likely, there is a theory that makes all observations look exactly like there is invisible matter without actually being invisible matter, or that there is invisible matter? I am going with the latter. I also do not understand why laypeople are of the opinion that all massive particles must interact electromagnetically. If you are open to the idea that there is a massive particle that doesn't, you got dark matter.

jug 5y ago

MOND theories etc. like this has fallen kind of out of favor because it’s just so hard to adapt our theory of gravity to resolve this. It’s surprising how often this topic pops up. I think it’s based on a misjudgment that simply missing something in gravity follows Occams Razor better but it actually seems to be the opposite. I think the killer is that dark matter seems to not just hold galaxies together (given their “too high” rotational speeds), but also clump together, and also sometimes be missing in galaxies and other times overwhelm galaxies. It’s super hard to adapt the well proven theory of gravity to especially localized phenomena.

pdonis 5y ago

> what do you think is more likely, there is this matter out there that no one has been able to find in decades of searching, or the mainstream assumptions/math on gravity are wrong/incomplete? You are mis-stating the real issue here. The distribution of matter is already a free parameter in our current theory of gravity, General Relativity. GR in no way requires that all matter be visible to humans. The "no one has been able to find" thing is not a problem for GR, it's a problem for the Standard Model of particle physics, which does not contain any particles that dark matter could be made out of. But most physicists already believe that there are more kinds of particles than the SM describes, we just haven't figured out how to make them in accelerators so we can study them in a controlled experimental fashion, and we haven't figured out any "smoking gun" signature that will tell us if such particles exist out there in the universe. "Dark matter" is really just a name for those kinds of particles that are already believed to exist anyway, we just can't detect them with the technology we currently have. But the technology we currently have is very limited. So the real question you should be asking is, what do you think is more likely, that there are particles that aren't included in the Standard Model of particle physics--which is already believed to be the case anyway--or that General Relativity is wrong in its description of the dynamics of galaxies, even though this is a domain in which GR has already passed stringent experimental tests with predictions accurate to many decimal places? I'm going with the former.