General Discussion
In reply to the discussion: UFOs exist and everyone needs to adjust to that fact [View all]PoindexterOglethorpe
(25,862 posts)does not come from galaxy centers.
Cosmic rays are out there, but they are not the same as the CMBR.
I keep on seeing 300 billion as the number of stars in our galaxy. Or, more precisely, 250 billion ± 150 billion. Notice that is plus or minus. So from 100 billion to 400 billion, with 300 billion as a nice median.
As you probably know, Milky Way and Andromeda are on a collision course. They'll crash into each other in a bit less than 4 billion years. A while back I asked My Son the Astronomer (because he knows things I don't know) just how many stars of the combined 1.3 trillion or so stars will actually crash into each other. He said, "Well, we're not entirely sure but probably not more than ten." That tells you more than anything else just how vast interstellar distances are. Of course, many more will interact gravitationally, but that's a different topic.
What sort of evidence do you have that the speed of light is not fixed?