Page 218 - Darwin's Dilemma: The Soul

Darwin’s Dilemma: The Soul

According to Einstein’s general theory of relativity, the speed
of time changes according to the velocity of a body and its dis-
tance from the center of gravity. As velocity rises, time contracts
and is compressed, in such a way as to run slower and eventually
approach the point of stopping altogether.
To use an example cited by Einstein, one of a pair of twins re-
mains on Earth while the other heads out into outer space at a
speed near that of light. When the traveling twin returns to Earth,
he will find himself much younger than his brother. The reason is
that time flows more slowly for the brother traveling at a high ve-
locity.
The same example can also be considered with regard to a fa-
ther traveling in a rocket moving at roughly 99% of the speed of
light and his son who stays on Earth. According to Einstein, if the

One of two twins sets off into Through a telescope, the
space at a speed approaching twin on Earth sees that
that of light, while the other the other twin appears
twin remains on Earth. younger than himself.

The twin who left
in a rocket returns
to Earth. The twin
who had remained
behind has aged,
while his astro-
naut brother is
much younger.
According to Einstein’s twin paradox, one twin remains on
Earth while the other sets off into space at a speed near that of
light. When the one who traveled into space returns to Earth,
he will find his brother to be older than him. The explanation
is that time passes slower for the twin traveling in space at a
high rate of speed.

216