This is just silly. The science is settled. There shall be no more debate.
No, they should not have done that: clear scientific malpractice. But I guess they wanted the fame they duly acquired. They also abandoned their original plan to repeat the measurement at three-monthly intervals, and let stand their single result.
And now for the bad news. Every experiment that looked for an aether drift - every experiment, I kid you not - actually found one. This includes Sagnac (1913), Michaelson & Gale (1925), and, especially, the numerous experiments of Dayton Miller, from 1906 to 1933.
Details here: http://www.orgonelab.org/miller.htm
After collating many experiments, Miller claimed the Earth had a velocity, relative to the aether, of about 298 km/sec. Today, we claim the Earth has a velocity, relative to the cosmic microwave background radiation, of about 370 km/sec. Plus ca change.
Damn straight!
“Is the speed of light really constant?”
Yes the speed of light is constant. It’s the speed of dark that is inconstant.
Why does everything spin? Galaxies, electrons, etc.