Recent content by mwsund

Wallace, After a brief look the paper seems reasonably approachable. I'm looking forward to reading it more carefully. I continue to be impressed with the patience many of the members of this forum have with naive outsiders struggling to get a grasp on this fascinating but compex field...

Wallace, Thank you for the reply. I actually think I understand your point (although I do not have any sense for the functional characteristics of a(t)). Is there more you can say about a(t) or references that can help a non-cosmologist understand?

Please excuse this interruption to a really informative exchange, but I have a much more basic question. If the observed increase in distance is a change in a metric, would it be consistent to argue that the change could be caused by a distortion (as mass causes a distortion, but with a...

Given the presumptive excess of DM over the stuff we can detect, isn't it likely that 'clumping' of DM either caused the formation of large-scale structures in the visible universe or that the same mechanism is responsible for clumping of both conventional and DM? But, if so, what mechanisms...

If, for sake of argument, we assume DM does exist and that it interacts gravitationally with baryonic matter, doesn't that provide it a way to dissipate its KE? Is that so inefficient that even 1% of the DM in our solar system could not be captured by a body with the mass of the sun? If...

Sorry to be so dense (no pun intended), but I assumed DM would aggregate gravitationally just as 'normal' matter does. What am I missing?

Ok, one more question. (The responses to my first two far exceeded my expectations, by the way. This forum is clearly populated by some very well informed and passionate people. Thanks.) Is there a detectable effect of DM on the motion of planets in our solar system? If not, why not?

So, it is so much easier to force agreement with an existing theory than to replace or modify it, until a theoretical breakthough comes along attempts to make an existing theory conform to observation will attract most of the attention. Is that the current state?

Garth, I wish I could have articulated the issues as concisely as you did. Thanks. It would certainly be helpful if the existence of alternative models were acknowledged in popular accounts. (Would it be fair to characterize the state of the model as being similar to, 2+2=3 is not in...

marcus, That the popular press is creating the distortion was one of my assumptions. (I included it as a possibility in my first question but didn't repeat it here.) I am glad to see you agree. Unfortunately, the popular press is the basis most people have for their understanding of...

petm1, Perhaps I should not have used the term 'independent'. What I am trying to get at is that the rate of expansion of space time may not depend on the amount of 'stuff' that resides in it. Another way to look at it: What if the expansion of the universe is what produces the 'stuff' that...

Garth, Thank you for your quick reply. As I'm not well-versed in the mathematics of cosmology I may have misunderstood your response, but aren't you assuming one current theory to be the correct explanation? Part of my question is more along the lines of, if observation and theory are in...

This is my second question. As I understand the currently popular explanation for the accelerating expansion of the universe, it is based on the hypothetical existence of a uniformly distributed form of expansionary energy. Again, as I understand expansion, it is not the movement of bodies...

I have two questions. They are related, but different enough that I think it makes sense to raise them in two separate threads. The first concerns 'dark matter'. The NYT article is a good example of what is bothering me: https://www.physicsforums.com/showthread.php?t=160464 (Please...