Is the light speed in the earth atmospher = to the light speed in the out space?
No. When light has to go through something, it will interact with it. This slows it down. In water, for example, light travels much slower than it does in the vacuum of space. This is why it is possible to have particles that travel through water faster than light travels through water. The particle does go faster than light in water (but it does not go faster than the speed of light in a vacuum, so this is still “legal”). Because it is going “faster than light”, the particle will emit a very specific type of radiation called Cherenkov radiation. http://en.wikipedia.org/wiki/Cherenkov_r… The factor by which light is slowed down is call the refraction index (because it is the exact same value that determine how much light is refracted when it enter that material). The index for air is 1.0002926 Therefore, the speed of light in air is c/1.0002926 c is the speed of light in a vacuum = 299,792,458 m/s in air, lig
