Recent content by Csmith

Nice graphic.

Yes, that seems like a good argument. My only question is: just how consistent are those structures? When I look at those photos, there seems to a lot of variation with those galaxy shapes, sizes, etc. So just how obvious would that conspiracy have to be? But I agree, given the kind of...

AGain, dumb question, but why does "one side move towards us and the stars on the other side are going the other way" mean they are "going in circles"? You mentioned that we know that from redshift, but doesn't the redshift merely give us the current velocities? You say this means they must be...

But the measured redshifts do *not* demonstrate a SSCM. What it looks like you are saying is that the galaxy must be SSCM by virtue of its structure *and* how we think it originated.

Can you explain why a "well-defined" structure means the galaxy cannot be dispersing? It isn't real clear to me why a spiral galaxy must be in SSCM, by virtue of its structure? Not saying this is false, just don't understand why this is true.

It may be the same equation but that doesn't demonstrate that stars are in elliptical orbits, right?

The elliptical paths is not the issue. Here is a https://dept.astro.lsa.umich.edu/ugactivities/Labs/tully_fisher/tf_intro.html. It says this: "We know that the Sun is moving in a circle around the center of the Milky Way. What keeps the Sun moving in this circle instead of flying away? Gravity...

No, my question is not about how fast galaxies are rotating. It is: How do we know galaxies are in SSCM, which is the model used to generate theoretical rotation curve. Make sense?

The observed galaxy rotation curve does not match the theoretical curve derived from the model that galaxies are in steady state circular motion (SSCM). The presence of dark matter would bring the SSCM curve up to the observed curve. But what observation demonstrates that galaxies are in SSCM in...