Physics question

[Sean]

The resolution to this paradox is the notion that time is not an absolute quantity in relativity, as it is in classical mechanics.  To say that the ship is 1 meter long the front of the ship has to be next to one side of the meter stick and the back of the ship needs to be next to the other end of the meter stick simultaneously.  So to do the measurement properly you need to put synchronized clocks on both ends of the meter stick and register the alignment with the front and back of the moving ship at the same instant.  However, according to relativity events which are simultaneous in one reference frame will not appear simultaneous in another reference frame.  To an observer on the ship the two clocks will appear to be out of sync.  From the ship's point of view the clock registering the position of the nose of the ship will click before the clock registering the position of the tail of the ship, which makes his ship appear shorter.  However, if the person in the ship attaches synchonized clocks to the nose and tail of his ship, the observer on the ground will see the ships clocks as being out of sync.

Wow, sounds good to me. It's been a long time since I was into this stuff, but I do remember 'the square root of one minus one over gamma squared', as the formula for speed needed for any particular Lorenz factor.