As I am sitting at my computer terminal busily typing, I feel the ever present pressure of my office chair on my buttocks, a pressure I have learned to live with (yet, I might add, that my buttocks are slowly reacting to in a very noncosmetic way). The force on my buttocks results from the pull of gravity, which if given free reign would accelerate me downward into the Earth.
Lawrence Krauss verbosely writes about his buttocks.
The Physics of Star Trek.
That’s right, if it weren’t for the normal force (the force perpendicular to the surface) of Mr. Krauss’s office chair pushing up on his “buttocks”, he would literally be pulled to the Earth AKA fall to the ground.