http://math.ucr.edu/home/baez/physics/Relativity/SR/rigid_disk.html http://math.ucr.edu/home/baez/physics/Relativity/SR/rigid_di... http://en.wikipedia.org/wik

http://math.ucr.edu/home/baez/physics/Relativity/SR/rigid_disk.html http://math.ucr.edu/home/baez/physics/Relativity/SR/rigid_di... http://en.wikipedia.org/wiki/Ehrenfest_paradox http://en.wikipedia.org/wiki/Ehrenfest_paradox Which is the best I could find for the question of shortening a quarter to the size of a dime using relativity.