maths: strange notation

nox · 2006 October 7th, 08:22

Greetings,

surfing in the web, I found the following equation in a postcard written by Maxwell to another physicist called Tait:

Can you tell me what the sign

means and explain me the meaning of this equation ? Here's a picture of the postcard:

I assume that the sign denotes a square root...

Thank you!
Ciao,
Alexander

4electros · 2006 October 7th, 16:30

the sign denotes the angle of a complex number and "i" is the comlpexity varible.

nox · 2006 October 7th, 18:07

Stupid question, but how do you know that ?

Martin · 2006 October 8th, 23:12

Quote:

Originally Posted by nox

Stupid question, but how do you know that ?

It’s pretty standard stuff. Do a search on “angle notation” or “phasor notation,” and you’ll find out a lot about its usefulness in physics and engineering.

nox · 2006 October 9th, 04:04

Hmm, yes but phasor is usually written as ∠ ? Not a completly underlined expression.

Plus that a phasor does not contain an imaginary number, because it's included in the sign itself: 1e^(ix) = ∠x; Consequently ∠(i+x) doesn't make much sense, does it ?

Okay - But if you are right... what does the equation mean ?

h0dgey84bc · 2006 October 9th, 04:24

looks very much like normalization of the legendre polynomials or spherical harmonics, just a guess though

h0dgey84bc · 2006 October 9th, 04:30

hmm perhaps not