Why is the symbol for angular momentum L?

[zhuangjieyi]

Why is the symbol for angular momentum "L?"

So far, the best explanation I've come across is:

This comes from the "right hand rule" of vector cross products. The vector for the radius, r-> and the vector for the translational momentum p-> when made into a cross product :
r-> x p-> = L->
Since r and p are in the x-y plane, they are perpendicular to each other and form an "L" shape when made to be part of a cross product.

 

[confinement]

m is for mass.

Momentum can't be m, since mass is m, therefore momentum will be p. Now that we have accepted such things, magnetic field cannot be m, so it will be B. Then the vector potential from which B is derived should be known as A i.e. A precedes B, and the potential A is all important. Therefore we cannot have angular momentum be A or M (or P, but who would want that?). Therefore we may as well call it L, as in Leonhard Euler, "the master of us all" whose description of rigid body rotation is still used today.

 

[flatmaster]

I tell students that that the way to remember "p" stands for momentum is to imagine it spelled with a silent p.

pmomentum

 

[alxm]

Momentum can't be m, since mass is m, therefore momentum will be p. Now that we have accepted such things, magnetic field cannot be m, so it will be B.

Haha, no. As I mentioned in the other thread, I know this one. It's 'B' for 'Borealis' - North. That's where the field points.

At least in the hemisphere where all the cool folks live. ;)

 

[confinement]

Of course, the magnetic field of the Earth always points to the north pole, even if you live in the southern hemisphere, since there is a magnetically south pole at the north pole!

 

[alxm]

Of course, the magnetic field of the Earth always points to the north pole, even if you live in the southern hemisphere

No no, the magnetic field is defined as having the opposite direction south of the equator. And South is at the top of their maps.

See?

 

[Dr.D]

No reason at all other than an arbitrary decision someone made. It makes no difference what you call it, as long as you define your symbols.

 

[evoluciona2]

L from the sound of angulus which is angle in Latin?