Dark matter that doesn't gravitate?

[chirhone]

If there is dark matter that doesn't gravitate, do you still call it dark matter?

Hossenfelder mentioned General Relativity can't be entirely correct because of quantum gravity, so this gives the possibility of dark matter that doesn't gravitate.

http://backreaction.blogspot.com/2019/08/how-we-know-that-einsteins-general.html?m=1

About how we detect this dark matter that doesn't gravitate. If there were other forces of nature that interacts with it, then it could be detected by more advanced detector.

 

[phinds]

so this gives the possibility of dark matter that doesn't gravitate.

Why would it?

 

[chirhone]

Why would it?

Because General Relativity being not entirely correct means it's not entirely true at all that mass/energy tells spacetime how to curve that causes gravity.

 

[phinds]

so this gives the possibility of dark matter that doesn't gravitate.

Why would it

Because General Relativity being not entirely correct means it's not entirely true at all that mass/energy tells spacetime how to curve that causes gravity.

I'm not sure that's a correct statement but even if it is, what does it have to do with dark matter? Why would dark matter be different than regular matter as far as gravity is concerned, since they both seem to act the same?

 

[chirhone]

Why would it

I'm not sure that's a correct statement but even if it is, what does it have to do with dark matter? Why would dark matter be different than regular matter as far as gravity is concerned, since they both seem to act the same?

That's why I was asking whether a theoretical third class of matter with behavior different from dark matter and regular matter should also be called dark matter? If not. Then we can invent new name for it like white matter. No problem. But then right now technically anything that is not regular matter is dark matter including matter that doesn't gravitate? This is to get the terms right when discussing it with public and theoretical physicists.

 

[Vanadium 50]

I think you might want to become an expert in a field before telling the experts that they have tehir terms wrong.

What you are speculating about - despite PF rules on speculation - is matter that interacts neither electromagnetically nor gravitationally, and as such is completely undetectable. The usual term for this is "invisible pink unicorns", things that can be speculated about but by their very nature unproveable.

 

[chirhone]

I think you might want to become an expert in a field before telling the experts that they have tehir terms wrong.

What you are speculating about - despite PF rules on speculation - is matter that interacts neither electromagnetically nor gravitationally, and as such is completely undetectable. The usual term for this is "invisible pink unicorns", things that can be speculated about but by their very nature unproveable.

But in the future, if technology can be made that can detect matter/energy that doesn't interact electromagnetically nor gravitationally, should it still be called "dark matter"? The detector can be certain pattern made of other forces that can affect the behavior of electrons like via the dark matter portal being talked about in arxiv or by theorists. My questions are based on them and not my own speculations.

 

[Bandersnatch]

The term dark matter represents that thing that is observed to interact gravitationally, but not in any other way (that we can tell). So if you were to talk about some different particle or phenomenon that doesn't interact gravitationally - hey, maybe it exists - that's not dark matter.

 

[jbriggs444]

But in the future, if technology can be made that can detect matter/energy that doesn't interact electromagnetically nor gravitationally, should it still be called "dark matter"?

You are asking about a naming convention for something that cannot be detected at present, may not exist at all but which you speculate might possibly become detectable in the future.

We should wait for detection and properties before awarding naming rights.

 

[chirhone]

By the way. What are theoretical tests to detect or prove that the strong force can also interact gravitationally?

 

[PeterDonis]

If there is dark matter that doesn't gravitate

Everything gravitates. Everything has energy, and energy gravitates. So your hypothetical here is not possible.

 

[PeterDonis]

General Relativity being not entirely correct means it's not entirely true at all that mass/energy tells spacetime how to curve that causes gravity.

No, that's not what it means. You are misreading Hossenfelder's article; she makes no such claim, nor does anyone else working on quantum gravity.

What are theoretical tests to detect or prove that the strong force can also interact gravitationally?

The question doesn't make sense. "The strong force" itself isn't a thing that gravitates. It's a separate interaction from gravity.

If you are asking how we know that strongly interacting particles (particles that feel the strong force) interact gravitationally, see what I said in my previous post about energy gravitating. If you want a practical example, Google "neutron star".

 

[PeterDonis]

My questions are based on them and not my own speculations.

Your questions are based on a fundamental misunderstanding.

Thread closed.