A colorful relativity problem

Abstract

The cover of the January 2005 issue of Physics Today is supposed to depict what the market square at Tübingen would look like if you were approaching it at 90% the speed of light. Offhand, I’m not sure this is what the square would look like at that speed, but I am sure the colors would be different. All wavelengths would be shorter by more than a factor of two. So, unless that little octagonal pond is actually red, you’ve got a problem with your relativity. Editor’s note: We invited Marc Borchers, who supplied the cover image, to comment. © 2006 American Institute of Physics.