OK - What happens to time if part of the the universe does not exist in a vacuum?
Einstein arrived at some of his ideas by picturing himself riding on a beam of light. What if that beam were slower due to passing through a medium? Would that affect simultaneity across the boundary of the medium? Wouldn't distant stars be seen in the more distant past? We know that time runs slower on the outside of a rotating disk than it does on the inside. Does time run at a slightly different rate underwater? This has no effect on relativity - in fact, I am trying to live within the confines of relativity.
Excuse me -
I was basing Einstein's statement regarding riding on a beam of light on The Ascent of Man, which was written by Jacob Bronowski (who knew Einstein personally I believe) and Cosmos by Carl Sagan, who used to work in pretty much the same job Dr Zikzak held. I guess you gentlemen know more than they do.
I have taken a class in relativity, and during that class I found that the professor was much easier to talk to and ask similar questions of than you gentlemen, who seem so over-impressed by your own admittedly superior knowledge that you respond by intimidation.
I understand that c is a fixed speed. I have understood that for decades. What I do not understand so well is how time works and how it is perceived. Thanks anyway.