"We obtained photos of Barack Obama taken every month from January 2009 until August 2014. ... by looking at photos of Obama’s hair over time, we can conclude that he is indeed getting grayer. [pnis.co]

http://feeds.boingboing.net/~r/boingboing/iBag/~3/1ZhmUj2h_PQ/a-quantitative-analysis-of-the.html