I've discovered a dual purpose for an old standard.
The other night, as we were getting ready for bed, I put on a pair of red satin pajamas that I a) love and b) am getting too paunchy for. Ted watched me, got a sly grin on his face, and asked, "Baby, are you feeling sassy tonight?" And with a completely straight face, I looked at him and replied, "I can't get comfortable when I sleep anymore. I toss from one side to the other at least 18 times per night. These pajamas reduce friction so I can swing my belly around easier." Ted's response: "Oh."
See, according to the equation F=M/a where "F" represents the net force of an object's motion, "M" represents the mass of the object, and "a" represents its acceleration, the relationship between mass and force is directly proportional. Therefore, if mass (my large fanny and larger tum-tum) increases, so must the force required to move that mass. If the force is a large one, acceleration is small (meaning the movement happens slowly - a fact all late-term preggers women know). That force/acceleration relationship is an inversely proportional one.
So to increase acceleration for the same amount of mass (because I'm only going to be getting bigger), I'd have to reduce the force. And since friction is the force that acts in direct opposition to the force of motion (think of sliding a heavy box across a carpet vs. putting it on a dolly), that's what I had to focus on reducing - hence the miracle of THE SATIN JAMMIES.
I should use this example during our force unit next year...