The basis and most observable metric for how the universe is understood to be expanding at an accelerating rate is the red shift in observable light. I am assuming it has been thought about or maybe it is just obviously wrong to people with more knowledge, but why can we not say the universe is technically always collapsing on itself under gravity's pull when considering relativity?

We know that space and time are affected by gravity so if we think in relative terms if everything is accelerating at an accelerating rate towards everything else this could explain the red shift (appearance of moving away). Things behind me would be accelerating slower towards the singularity things in front of us would be accelerating faster. Therefore relative to us it would actually look like it is all expanding at an accelerating rate, explaining the red shift.

In this very simplistic thinking, this would work for a universe that expands and contracts or is in a never ending state of contraction, which relative to us could go on infinitely since time and space is all intertwined with gravity.

  • $\begingroup$ Have you read Wikipedia's page on the Expansion of the Universe ? Your ideas, as I understand them, directly contradict what is known. Also understand there is no center to the universe and hence no concept of "behind" or "in front" as you seem to suggest. $\endgroup$ – StephenG Mar 18 '19 at 19:30
  • 2
    $\begingroup$ I'm voting to close this question as off-topic because this is about a personal theory with so evidence cited in support of it. $\endgroup$ – Chappo Hasn't Forgotten Monica Mar 19 '19 at 10:38
  • $\begingroup$ Hi new contributor! Be very cautious with phrases like "it appears to me," as that's a red flag for unsubstantiated wishing/guesswork. If you are starting from some technical sources, please cite them and explain your derivations. $\endgroup$ – Carl Witthoft Mar 19 '19 at 14:56
  • $\begingroup$ Thanks for responding. I have read this Wikipedia page. I'll probably go back and and see if I can further my understanding. I thought about explaining I knew there was no center, because i was using a very simplistic example of my theory. Really this would not affect the concept of just everything (including space-time) accelerating towards everything at an accelerating rate. $\endgroup$ – Scott Mar 20 '19 at 4:38
  • 1
    $\begingroup$ But yeah, you might want to delete the sentence "here is a theory" in order not to upset people. You might even want to read up on the difference between theory, hypothesis, and ideas :) $\endgroup$ – pela Mar 20 '19 at 10:37

If you work out the equations of motion for the gravitational free-fall collapse of a clouds of particles (or galaxies), you will find that, from the point of view of any of these particles, all other particles appear to be approaching. This is true in both Newtonian theory and general relativity.

The calculation is found in numerous text books and lecture notes, e.g. Susanne Höfner's, but a qualitative argument goes like this:

From your point of view, sitting on one of the particles, a particle farther from the center of the cloud does "feel" a smaller gravitational pull from the central particles. This is, I think, the reason that you think it should accelerate more slowly. However, any particle feels the gravity from all particles that are closer to the center, so the farther you are from the center, the more particles will attract you. On the other hand, the gravity from all particles that are farther away from the center cancels out, so you don't feel those.

This is, in essence, Newton's shell theorem, and it turns out to imply that all particles reach the center at the same time. The distance between each particle is getting smaller and smaller, until the cloud collapses into an point after a a time inversely proportional to the square root of the density.

This is exactly opposite to what is observed.

|improve this answer|||||

Not the answer you're looking for? Browse other questions tagged or ask your own question.