Relativity Project

These models are examples of student work on a project on special relativity in a multivariable calculus class.

The first, lightcone.stl is a schematic model of a light cone (represented with two spatial dimensions, plus time), illustrating where in space time one can get to under the restriction that one cannot travel faster than light.

The second gives a possible resolution to the Ehrenfest Paradox: what happens if you try to spin a solid disk at relativistic speeds? The paradox lies in the fact that the outside of the disk will undergo greater Lorentz contraction than the center. The students decided that a possible resolution would result if the disk curled upward, thus reducing the circumference at the edge. Their calculations and an interactive widget are here, and the reldisk.stl model illustrates a disk, and how it might curl if spun fast enough.