ullman to chapman and her "fast car" there are great tracys out there including spencer tracy and dick tracye cities and towns named tracys in at least six u.s. states and more in canada and france. last night's mention was aimed at our senior domestic producer tracy lyons, among the great and completely unconventional tracys of all time. >>> lindsey vonn talked about her most recent injury during a visit here today. she said she has a partial acl tear in the right knee. she said normally she'd stop competing to have it repaired. instead she hopes to compete next week. then to the olympics in sochi, russia. she's the most heavily decorated female skier in the history of the sport. >> in february when i crashed, you know, i had a lot of time. so i had enough time to be sad, disappointed and then get motivated. i don't have time for that now. i have to be motivated. i have to be ready. sochi is the thing that's really driving me. if i didn't have sochi, i would have most likely had another acl reconstruction and been out the entire season. sochi is definitely in the forefront of my mind. it's

now you know why dick tracy used to say, "he who controls magnetism controls the universe." look at the force of this little dinky magnet compared to the size of the world pulling all these clips up. so we can talk about the magnetic force today, gang, the magnetic force. ain't that neat? okay. this is a pretty powerful magnet. here's a pretty weak magnet. this one is suspended on a point, and it's magnetized. and what do we call it, gang, do you know? begin with c, end with ompass. try it. put it together. compass. compass, excellent. that's a compass. and guess which way it's pointing. north. you know what it's doing? it turns out that the whole world is a great big, begin with m. magnet. magnet. and surrounding that world is a magnetic field and guess what that compass lines up with, begin with m, f, the magnetic field of the earth. and that magnetic field in this room is oriented like this, okay? but what is the source of that magnetism? the source of that magnetism was betrayed years ago, more than 150 years ago by a fellow by the name of hans christian oersted, who was