[math-fun] Check your color vision.

http://www.tweedledum.com/rwg/squares.htm problem 2, can you see the color boundary between "18" and "14"? Maximal zoom. Slide "10" and "4" off the left edge to show only the middle right portions of "14" and "18". Slide up and down. Suspicion: Girls can see it better. Color vision is on the X chromosome. —rwg ("8" and "10" are identical shades of light blue. Proof: TextEdit>Format>Font>Show Colors> <eyedropper>.) I used to grumble at color-enhanced astronomy photos. Until I realized I am colorblind compared to most space aliens.