4 ms·

This torque issue was really bothering me, and I finally realized why: I was pretty sure I'd already seen torque represented by a letter other than tau. Sure en

by mhartl 16y ago

This torque issue was really bothering me, and I finally realized why: I was pretty sure I'd already seen torque represented by a letter other than tau. Sure enough, I checked my copy of Introduction to Electrodynamics by David Griffiths, which is a popular (and truly great) intermediate E&M text, and there it was on p. 162: torque written as N = r X F. The same usage appears in several other places in that book, and Introduction to Electrodynamics is a standard text, so I'm confident that other sources use it as well. So we see that the idea of using a letter other than tau for torque is not some theoretical possibility—it has already happened, and in a standard textbook to boot. I've updated the manifesto with a note to this effect at http://tauday.com/#sec:four_arguments http://tauday.com/#sec:four_arguments. I realize that this may not convince you, but I urge you to reserve the right to change your mind about tau. After all, I changed my mind about pi. ;-)

eru 16y ago
And there are only so many letters in the alphabet(s). Although I have to admit common usage hasn't really exhausted the hebrew alphabet, yet. And when the Chinese finally take over, we will have enough short symbols to last us for millenia.
Kadin 16y ago
I remember vaguely from my time using Griffiths' book that he uses a lot of non-standard (or at least not the same as other, more introductory textbooks) notation. He pretty freely reassigns the symbols used by things that you're supposed to understand, in order to free them up for other purposes. Or at least that's my vague recollection. It's been a few years now since I've cracked open his Electrodynamics. It was a pretty decent book though, better than a lot of textbooks (I kept it and still have my edition around somewhere, something that I didn't do if I thought a textbook was crummy).
amalcon 16y ago
Interesting. N may not be such a great symbol to use for torque, because the equation relating it to force and radius is a cross-product. In that context, N often refers to a "normal" vector. Still, it's apparently in use somewhere, which is interesting.

by mhartl 16y ago

eru 16y ago

And there are only so many letters in the alphabet(s). Although I have to admit common usage hasn't really exhausted the hebrew alphabet, yet. And when the Chinese finally take over, we will have enough short symbols to last us for millenia.

Kadin 16y ago

I remember vaguely from my time using Griffiths' book that he uses a lot of non-standard (or at least not the same as other, more introductory textbooks) notation. He pretty freely reassigns the symbols used by things that you're supposed to understand, in order to free them up for other purposes. Or at least that's my vague recollection. It's been a few years now since I've cracked open his Electrodynamics. It was a pretty decent book though, better than a lot of textbooks (I kept it and still have my edition around somewhere, something that I didn't do if I thought a textbook was crummy).

amalcon 16y ago

Interesting. N may not be such a great symbol to use for torque, because the equation relating it to force and radius is a cross-product. In that context, N often refers to a "normal" vector. Still, it's apparently in use somewhere, which is interesting.