The demand for ball bearings—on automobiles, ... but in fact that honor goes to the ping pong–size spheres of fused quartz that serve as gyroscopic bearings for the satellite Gravity Probe B.

Bearing size is increased because a larger ball and retainer must be moved. ... Very-high contact angles have higher torque levels because of the sliding motion in the ball-to-race contact area.

The first modern ball bearing design was developed in 1794, and they started going into bicycles in 1869. Everything from yo-yos to watches to jet engines use ball bearings in one way or another.