Suppose the straight-line distance between New York and San Francisco is 4.4 106 m (neglecting the curvature of the earth). A UFO is flying between these two cities at a speed of 0.69c relative to the earth. What do the voyagers aboard the UFO measure for this distance?

Answer 1

L=L₀•sqrt{1-(v/c)²}=
=4.4•10⁶•sqrt{1-0.69²}=3.2•10⁶ m