[DoctorBeaver]

Eh? I thought it was as a result of trying to establish why galaxies don't lose their stars.

You can say it that way, but it seems kind of odd; the stars had to get where they are by the force of gravity. We used to simply say that some galaxies spin too fast. But it is true that according to Newton, stars in those too-fast galaxies should fly off into space.

Exactly. So something is either pulling on them to hold them in place (gravity in the form of dark matter), or there is a pressure pushing them from outside the galaxy that is holding them there.

[Vern]

Exactly. So something is either pulling on them to hold them in place (gravity in the form of dark matter), or there is a pressure pushing them from outside the galaxy that is holding them there.

This reminds me of the push-gravity scheme that was popular some years ago. I think it was Feynman's firm rejection of that notion that was its demise.

[DoctorBeaver]

What I'm thinking is a bit different from that

[Vern]

What I'm thinking is a bit different from that

Interesting; is it something you can describe?

[DoctorBeaver]

What I'm thinking is a bit different from that

Interesting; is it something you can describe?

I'll try to write it out first then post it here if I succeed

[Vern]

I'll try to write it out first then post it here if I succeed

Thanks; I'll be watching for it.

[demadone]

The biggest reason why we suspect the existence of dark matter is the fact that galaxies form clusters and super clusters. the distances are too big for them to be held by ordinary gravity.

Maybe there is a kind of gravity that results from atoms that is weaker than gravity but can on very large distances. I believe this is the first time this is being said. I can explain why...

[Vern]

The biggest reason why we suspect the existence of dark matter is the fact that galaxies form clusters and super clusters. the distances are too big for them to be held by ordinary gravity.

I don't think you have this exactly right. The first mention I see is in measurements of the speed of rotation of galaxies. Some galaxies are seen to be spinning so fast that stars on the outer parameter should be flying off into space.