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Originally Posted by towny
Galileo, I think, using the motion of Jupiter's moons. Apparently his initial calculations were reasonably accurate.
EDIT Or was it Newton?
Some brainy classical dude with a telescope, anyway.
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the 'modern' classic experiment was the 'Michelson-Morley' one, which demonstrated that the speed of light was a constant, independant of the speed & direction of the emitter. i.e. the same speed from a star moving towards us as from a star moving away.
- the shift in frequency of the light depending on its direction relative to the observer (red shift & blue shift) is what enables us to estimate the relative speed & distance of the stars to our sun. It is the fact we observe most stars light as red shifted that forms one of the main 'proofs' of the 'big bang'.
so if the Universe really is expanding, those aliens should get here sooner rather than later, or we will all be too far apart
