Nerd joke
U.S. nerds probably won't get it due to different unit system in use there :-)
Einstein, Newton and Pascal are playing hide and go seek.
It’s Einstein’s turn to count so he covers his eyes and starts counting to ten. Pascal runs off and hides. Newton draws a one meter by one meter square on the ground in front of Einstein then stands in the middle of it.
Einstein reaches ten, shouts "Ready or not - here I come!" and uncovers his eyes. He sees Newton immediately and exclaims "Newton! I found you! You’re it!"
Newton smiles and says "You didn’t find me, you found a Newton over a square meter. You found Pascal!"