Einstein's theory said that the speed of light is a constant (around 1000000000 km/h). Some weeks ago I've been reading an article at slashdot.org that scientists have been able to slow down light to 65 km/h.
Since I didn't read Einstein's theory I have a problem now. :)
If Einstein said that the speed of light is around 1000000000 km/h and the scientists have slowed it down to 65 km/h then Einstein was wrong about the constant speed, right? But if Einstein said that the speed of light is a constant, not mentioning the actual speed of it or mentioning that the speed of light in a vacuum is 1000000000 km/h, then the speed of light in some other medium can be still a constant, but at different speed, right? So both, Einstein and scientists, can be correct, right ?