Which one? Are you talking about the balloon example. This is just a simple way of illustrating the expansion of the universe. BTW, its more than just the galaxies flying through space, space itself is expanding. I thought he explained it pretty well. At every point in space, if space is expanding, then everything is moving away from everything else. I know its hard to grasp for someone who has never given any thought to physics being valid, oh wait you still claim to have a chemistry degree from 1995 right. Did you take no physics in college? What chemist doesn't have to take some physics classes?
Physics 101, or rather 201 (intro to physics with calculus)for my degree, dealt with gravity, friction, and other forces. Physics 202 dealt with electromagnetic waves and electricity, Physics 332 was basically thermodynamics, physics 341 was optics, and physics 361 was atomic and molecular structures with a little quantum mechanics thrown in.
Of course, I am sure that you getting a science degree had to do no physics classes or labs. Surely those things are not needed for a chemist. (BTW thats a little sarcasm there).