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Comment by jjoonathan | Hacker News Reader

How does your theory fit with flat rotation curves?

My "theory" is just a hunch. Flat rotation curves IS the primary foundation for the existence of dark matter:

https://en.wikipedia.org/wiki/Galaxy_rotation_curve

I'm simply saying its more likely an unknown effect of the black hole at the center. Possibly some sort of gravitational modification effect that only occures in the presents of singularities. The fact that a sparse galaxy with possible no black hole center (I assume) shows no sign of dark matter is compelling. It may not prove the specific equations/explanations set forth in MOND, but it may hint to some other alternative gravitational theory that has yet to be flushed out, rather than relying on some invisible particles which may not exist.

While rotation curves were one of the earlier indications of dark matter, we have perhaps stronger evidence now from CMB measurements, gravitational lensing studies, and structure formation considerations.

Got any links for cosmology laymen? I'd be curious to see if my "theory" is negated.

Not sure if this is the right level or not, but one place with nice animations is http://background.uchicago.edu/~whu/animbut/anim2.html

I'm not a physicist, but that was my thought exactly.

Black holes are weird objects, they are enormous, have huge mass and density, almost no radiation, have great gravitational effect on surroundings and they are hard to detect etc.

They seem like a perfect candidate for 'dark matter'.

Could anyone explain why it is wrong?

They're detectable and already taken into account.

So according to wikipedia [1] they have been looked into, they would fall under the category of MACHOs

1. https://en.wikipedia.org/wiki/Dark_matter#Baryonic_matter

Black Holes of reasonable can be detected by gravitational lensing. If Black Holes / Brown Dwarfs / etc. were primarily responsible for the dark matter locally, lensing searches would have detected more. See e.g. https://arxiv.org/abs/astro-ph/0002058 for an overview.

This graphic can explain very clearly, although it’s a little old. The result is that constraints today are even tighter though, so for these purposes it’s still useful.

https://4.bp.blogspot.com/-UN8jPwzj2qI/V9hRVCG1HBI/AAAAAAAAC...

My "theory" is just a hunch.

It looks like Occam's razor. To explain an unexpected result, you label the problem so it looks like it must be a new entity.

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