Feb 7, 2023 04:43 PM
(This post was last modified: Feb 7, 2023 06:54 PM by C C.)
Do we live in a rotating universe? If we did, we could travel back in time (i.e., Gödel metric)
https://www.space.com/rotating-universe-...ime-travel
The galaxy cluster that broke modified gravity
https://bigthink.com/starts-with-a-bang/...d-gravity/
We can measure the amount of matter in the Universe and also the effects of gravity, and these two methods, with normal matter alone, just don't add up. One can imagine either adding a new ingredient, like dark matter, or changing the laws of gravity, modifying them from Einstein's original form. But one class of systems, that of colliding galaxy clusters, gives us a way to tell the two ideas apart. Unless modified gravity is a near-perfect dark matter mimic, the idea falls apart in the face of this evidence.
https://www.space.com/rotating-universe-...ime-travel
The galaxy cluster that broke modified gravity
https://bigthink.com/starts-with-a-bang/...d-gravity/
We can measure the amount of matter in the Universe and also the effects of gravity, and these two methods, with normal matter alone, just don't add up. One can imagine either adding a new ingredient, like dark matter, or changing the laws of gravity, modifying them from Einstein's original form. But one class of systems, that of colliding galaxy clusters, gives us a way to tell the two ideas apart. Unless modified gravity is a near-perfect dark matter mimic, the idea falls apart in the face of this evidence.
