this one's for you, disclaimerwill

[fflo]

Crossing AXH's desk this morning (drum roll).... the hairy ball theorem! 6 hits in MSN.

Kinda looks like it boils down to the notion that every continuous vector field on $S^2$ has a zero. Whatever that means.

Comments

[paperkingdoms]

Yes, yes it does. It means, roughly, that if you had a sphere covered with hair, and tried to make it all lie down flat with, say, a hairbrush... you couldn't. There'd have to be an odd spot somewhere where stuff stuck up.

Thus you have topologists announcing that "you can't comb the hair on a bowling ball"... and feeling very clever for it. ;^)

[We actually used this fact in one of my classes a week or so ago.]

[fflo.livejournal.com]

Ah. So you try to comb the balls with a hairbrush. I'll pass that along at work!

[paperkingdoms]

I'm sure that'll make it all better. ;^)