Re: [math-fun] The (_|_) and 6pents

Joshua Zucker:

I connected them to form a black rectangle and then it looked like a rectangle (they looked the same length). It seemed like the "smaller" one stayed the same size when I took those perpendicular lines back off, while the "longer" one seemed to jump to a bigger size when they disappeared.

I've played around with this a bit as well. The illusion seems stronger to me when the lines are vertical: http://chesswanks.com/pot/TwoLines.jpg If my jpg conversion maintained my thinner lines' thickness, the "longer" line also appears darker.