Recent content by rundal

Okay, I can see that's way too sparse to experience substantial time dilation. If I keep narrowing the separation between objects, if only by growing the dark stars or black holes by adding mass, eventually I guess it'd be obvious there's dark baryonic matter there, like the visible stars would...

Can you elaborate on this? What is the basis of the assumption that the dark matter can't be dark stars or black holes, for the Bullet Cluster? In which case it seems we could expect them to stay with the stars and not the gas.

I can do the math in my head, to know that if enough dark mass is packed into the galaxy's central bulge, it's possible to inaccurately measure the orbital velocity of a star to any degree. That's why I'm asking how this possibility is ruled out. I'm not the OP. My questions are within the...

Okay, so I guess if the central bulge was much more dense, say distances between astronomical objects averaging 0.05 light years, with 10000 dark stars (maybe black holes) for every visible star, we'd definitely notice this, right? We'd notice gravitational lensing, visible stars being dimmed or...

The current thinking is that the flat rotation curves are accurate. I'm indirectly asking about the possibility that maybe the curves aren't flat if they were completely locally measured. The copious amounts of matter I'm talking about wouldn't be distributed the same as is currently thought it...

I'd still like to know how we're sure it's a tiny effect in this case. What if for every star in the galaxy's central bulge that we see, there are 1000 black holes, or highly compact / highly redshifted stars, all orbiting the galaxy's center? I suppose we could rule that out because we don't...

I see. Just entertaining ideas here, how can we know that for sure? Presumably to get that one part in 100,000 result you need the mass, and to get the mass we measure orbital velocity. But maybe the orbital velocity is slowed by significant gravitational time dilation, so we're fooled into...

How do we know what to expect, without knowing the depth our gravity well, relative to the depth of the gravity well of the galaxy we're observing? As a hypothetical example, suppose our closeness to the barycenter of our local group of galaxies makes clocks close to the center of the galaxy...