I wonder what the barometer reading was when they decided to clock the speed of sound?
Lightspeed is measured as the speed of light through a vaccuum, but did you know a recent experiment shows that we can actually send an object much quicker than the speed of light? In fact, it's possible, more or less, to create time travel. With energy waves only so far.
Oh yes, some scientists rigged up a chamber with a lazer on one side, and a recording device on the other. When they shot the light into the chamber, it actually appeared on the other side before it entered all the way. I forgot what they had inside the chamber for the moment, so if one of you guys know, help me out. I guess that's time travel anyway.
In the most basic sense, light can be refracted, so obviously that would mean a shorter or longer distance as far as a straight line is concerned. That would indicate in the most crude fashion that the speed of light can be affected by a medium. Which of course is why the speed of light is measured in a vaccuum.