He wants you to run, he wants you to walk, he wants you to jump outside instead of being cooped up inside in front of the TV playing videogames.

WHITEHOUSE: Run Across America at the White House

Then it's immediately on to next year which teams are getting better, which ones are getting worse, and then the NFL combine, in which prospects inside an unoccupied stadium run and jump.

WSJ: Jason Gay: Do Sports Fans Need an Off-Season?

This is made of sheets of carbon, inside which electrons can flow smoothly, but between which they cannot easily jump.

ECONOMIST: Magnetism