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Unformatted text preview: u run east or west, however, not
only will the wind seem to change speed, so will its direction.
Now imagine a race between two equally fast swimmers. They each go
the same distance in a river, but one goes upstream and back while the
other goes directly across the river and back. With no current the race
would definitely be a tie, since their speeds and distances are the same.
With a current, however, the cross-stream swimmer will win. This is not
obvious. You should try to prove this. For a hint see the “
river crossing--relative velocities” slide from the presentation on vectors. It
involves the same principle as Michelson’s interferometer (but without
Michelson-Morely Michelson-Morely Experiment (cont.)
Michelson built something called an interferometer
to try to measure a change in the speed of light in
two different directions. The Earth moving through
the ether around the sun is analogous to a wind or
current. Instead of racing two swimmers, Michelson
raced beams of light. Light was shone onto a mirror
that allowed half...
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This note was uploaded on 11/17/2011 for the course PHYS 121 taught by Professor Burgeson during the Fall '11 term at BYU.
- Fall '11