文档介绍：Space and Time Warps
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In science fiction, space and time warps are monplace. They are used for rapid journeys
around the galaxy, or for travel through time. But today's science fiction, is often tomorrow's
science fact. So what are the chances for space and time warps.
The idea that space and time can be curved, or warped, is fairly recent. For more than two
thousand years, the axioms of Euclidean geometry, were considered to be self evident. As
those of you that were forced to learn Euclidean geometry
at school may remember, one of the consequences of
these axioms is, that the angles of a triangle, add up to a
hundred and 80 degrees.
However, in the last century, people began to realize that
other forms of geometry were possible, in which the
angles of a triangle, need not add up to a hundred and 80
degrees. Consider, for example, the surface of the Earth.
The nearest thing to a straight line on the surface of the Earth, is what is called, a great circle.
These are the shortest paths between two points, so they are the roots that air lines use.
Consider now the triangle on the surface of the Earth, made up of the equator, the line of 0
degrees longitude through London,