¥Special relativity could
only be used to describe anything involving motion in a straight line with
constant velocity.
¥The special theory of
relativity could not be applied to situations involving forces, such as
electromagnetic forces or the force of gravity, since they seldom involve
motion in a straight line with constant velocity.
¥Einstein was able to
show that no simple modification of the special theory of relativity could fix
these problems. A new theory was
required:
¥The General Theory of Relativity