Sorry, MD, you're all wrong. Absolute rest has been out of date since Galileo. Einstein's says that's reality "As judged from the embankment." The actual velocity of the embankment is arbitrary. It's certainly not supposed to be floating in space, unmoved by the Earth's orbit around the Sun, or the Sun's motion through the galaxy, or the galaxy's motion toward Andromeda. Where do you think Einstein says that the embankment is at absolute rest? Look. Here's a 1972 experiment that measured the speed of light in a laboratory to within 1 m/s. They didn't adjust for the Earth's rotation or orbit. This measurement has been repeated and improved upon. No one has found it necessary to adjust for Earth's motion, yet they all get the same results. What does that tell you?