Inertia

This morning, I drove my daughter in to school. I wanted to give her the chance to talk with me about our desire to have her take a preparatory shot at the Scholastic Aptitude Tests. She didn't, but we did talk about fog, and where it comes from, which segued into a discussion of The Jetsons, and how they would just raise their house above the fog if needed. She speculated that they must be on a very long pole, or perhaps the house has thrusters underneath. I said no, it was lifted by anti-gravity, which we might actually have some day. She replied that if we did, we would need something to keep us from just floating away, and I agreed, saying that inertia could be a problem. What's that, she asked, and I said that it was like when you flicked a finger at a ball sitting on a plane, and the ball kept moving after you let go. There's a famous physical law about that, I said -- 'An Object Placed into Motion Will Tend To Remain In Motion' -- and she said 'Until Stopped By Another Force or Object'.

Damn. I almost went off the road, I was so delighted.