Instead of 254 miles up in the ISS, these days link you can find Dr. Williams link soaring in link the skies above Hamilton, Ontario, where he regularly flies warbirds out of the Canadian Warplane Heritage Museum as a hobby. In addition, he's recently written a memoir about his impressive career. Of course we talked watches, but the conversation was peppered with these rare moments that were entirely transcendental. I was absolutely in awe the entire time.

MIT: To keep time, people need something that is very regular link to measure against. For many centuries, people used the motion of the earth around the sun. The year and day became the standard at first, then the hour and the minute. But the truth is that it isn't exactly regular. The planets are pulling on the earth a little bit and creating slight variations.