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The Question
(Submitted January 06, 1997)
My daughter needs URL pointers to help her understand the subject of
space time. Are you able to recommend any? Thanks!
The Answer
Spacetime is a fascinating topic to physicists and astronomers. It
all began in 1905 when Albert Einstein published the Special Theory of Relativity, which showed that space and time are both altered near the speed
of light. To an observer, distances (space) appear to contract and clocks
tick more slowly. Later, Einstein revolutionized the way we think of gravity.
General Relativity states that gravity arises when mass warps spacetime; it's
not a force acting at a distance.
The spacetime around massive compact objects like neutron stars and
black holes is so warped that surprising distortions occur. A couple of examples are available on the World Wide Web. Try:
- http://www.ncsa.uiuc.edu/Cyberia/NumRel/NumRelHome.html for an overview of
relativity and some numerical simulations of the consequences of very
distorted spacetime (like the collision of two black holes!) The
links from this page provide a pretty good introduction to the concept.
- http://antwrp.gsfc.nasa.gov/htmltest/rjn_bht.html for movies that show
what it would look like to fly close to a compact object.
I think these links will be a good start for you and and your
daughter.
Have fun,
Padi Boyd,
for Imagine the Universe!
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