¥Einstein's theory of
relativity changed the foundations of physics.
¥Many basic concepts,
such as the relativity of space and time, are a direct consequence of the
"absoluteness" of the speed of light.
¥The new theory is
logically consistent and mathematically very elegant.
¥The new theory
"contains" Newtonian physics as an approximation valid for speeds
much smaller than the speed of light.
¥However, the new theory
would be worthless if it didn't agree with reality (i.e. experiments) better
than classical physics.