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Aug20-04, 07:11 PM
PF Gold
Simfish's Avatar
P: 828
IIRC, the speed of light can actually be modified in everyday circumstances. Or so as the textbook says, light is refracted when it travels between air and water because its speed is slightly different in water and in air. Similar when light travels between other media.

And the speed of light is defined to be what it is in a vacuum.