This, however, misunderstands the nature of the motion: a molecule will bounce off the sphere around 10 20 times per second, and although that only makes a tiny difference to the sphere’s velocity, in...This, however, misunderstands the nature of the motion: a molecule will bounce off the sphere around 10 20 times per second, and although that only makes a tiny difference to the sphere’s velocity, in one hundredth of a second the average imbalance, √N, will be of order 10 9 , enough to make a change in a small sphere’s velocity.
