By Science News, 12:16 PM October 6, 2011

Lumpy lunar illusion
Are you folks aware of a phenomenon based on the universal expectation that objects are illuminated by light coming from above? Several startling optical illusions are based on this quirk of the mind. For example, the sharp moon map in “Orbiter delivers sharp moon map” (SN: 7/30/11, p. 12) makes the moon look like it is covered with big bumps! Turn the page upside down, and voila — the bumps turn into craters.
Jeff Brewer, Newton, Mass.

Count on crows to know

Source URL: https://www.sciencenews.org/article/letters-95