Caltech scientists have found a fast and efficient way to add up large numbers of Feynman diagrams, the simple drawings ...

However, you can't just run up a vertical wall because there would be no (or very little) normal force between your foot and the wall. With no normal force, there is no friction. That's bad.

We are going to measure distance and time for an accelerating object and use that to find the acceleration. In the past, I would do this lab using a specialized drop timer.

The average football sack can produce a bone-shattering 1600 lbs of force. Armed with new tools, researchers are now studying the science of a gridiron fundamental: The tackle.