William Thomson Kelvin (1824 - 1907) who proposed the absolute or Kelvin temperature scale. He also established the second law of thermo-dynamics. He was brilliant. But he wasn't perfect. W. & D. Downey/Getty Images hide caption

itoggle caption W. & D. Downey/Getty Images

Pathologist Thomas Harvey took dozens of photos of Einstein's brain. This one shows that Einstein's prefrontal cortex (associated with higher cognition and memory) is unusually convoluted. On the right side of the brain there are four large ridges, where most people have only three. Brain(2012)/National Museum of Health and Medicine hide caption

itoggle caption Brain(2012)/National Museum of Health and Medicine

A detail from what is thought to be one of only three existing manuscripts containing Einstein's most famous formula about the relationship between energy, mass and the speed of light — in his handwriting. Sean Carberry/NPR hide caption

itoggle caption Sean Carberry/NPR