Nov 08 2008
Spacetime
The universe has at least three spatial and one temporal (time) dimension. It was long thought that the spatial and temporal dimensions were different in nature and independent of one another. However, according to the special theory of relativity, spatial and temporal separations are interconvertible (within limits) by changing one’s motion.
There are now other theories involving the universe having more that the above dimensions. There is disagreement among scientists about such theories. I believe these other theories cannot be tested or proved. So for now Einsteins Special Theory of Relativity explains space time relationships.
High-precision test of general relativity by the Cassini space probe (artist's impression): radio signals sent between the Earth and the probe (green wave) are delayed by the warping of space and time (blue lines) due to the Sun's mass.
Image courtesy of NASA
