MIT 3.60 Lec 2b Symmetry, Structure, Tensor Properties of Materials
PROFESSOR: Another strange observation about mirrors that I've never really understood-- the mirror plane is reflecting me left to right, so it looks as though a mirror has a grain to it. It knows what line to reflect me back and forth. But if I kept the mirror in fixed orientation and I lay down, the thing should reflect me side to side, but it doesn't. It still reflects me from top to bottom. So how can that be? Why does a mirror plane, if I hold it in one orientation, appear to have a direction across which I'm reflected but it doesn't follow me if I move? Know what I mean? You have any explanation of that? Hmm? AUDIENCE: Rotate your eyes, too. PROFESSOR: Rotate my eyes. I can roll them around. I can't rotate in any other fashion. That's strange. I mean, you look at yourself every morning-- several times, perhaps, and you're reflected always left to right. And if you turn the mirror, it doesn't reflect you top to bottom. Or conversely, y...