Orodruin's latest activity
-
Orodruin replied to the thread Tension in a string connecting two blocks having equal and opposite velocities.Of course they can, but not at all times. -
Orodruin replied to the thread A Decomposition into irreps of compact Lie group.I think I found my issue. I was trying ##\sin^2(\theta)##, but when mapping from SU(2) to SO(3), the ##t## here is actually...
-
Orodruin posted the thread A Decomposition into irreps of compact Lie group in Linear and Abstract Algebra.When decomposing a representation ##\rho## of a finite group ##G## into irreducible representations, we can find the number of times the...
-
Orodruin replied to the thread B Newton's first law?.For things moving free or at rest, Observe what the first law does best. It defines a key frame, Inertial by name, Where the second law...
-
Orodruin reacted to PeterDonis's post in the thread A A global energy conservation law in general relativity with
Like.
You should resist the temptation. All you have done is rediscover the Komar energy. Which is a perfectly good integral conserved... -
Orodruin replied to the thread I How to calculate basis vectors from metric tensor (as a matrix)?.You’ve gotten things wrong. The basis is a choice. The typical coordinate basis depends only on the coordinates chosen - the manifold...
-
Orodruin replied to the thread Can a dipole be modeled as a point charge?.Your post seemed to indicate otherwise …
-
Orodruin replied to the thread Can a dipole be modeled as a point charge?.This dependence is present also far away from the dipole.
-
Orodruin replied to the thread Independent components of three indexed systems ##T_{ijk}##.There is no need to split into cases as you do. The third index is just an additional copy of the 2-index system for every possible...
-
Orodruin replied to the thread Flux through a cylindrical surface enclosing part of a sphere.Hint: You don’t need to compute the flux integral. Edit: with the dimensions of A, the cylinder does not completely enclose the sphere...
-
Orodruin replied to the thread Writing a vector parallel and normal to a unit vector ##\hat n##.There is actually a generalization of the cross product to arbitrary dimensions that will do the same trick asthe cross product...
-
I don't think saying they are all invariant objects removes the distinction between them. A vector has a magnitude and direction whether...
-
Orodruin replied to the thread I Invariance of 4-velocity.A scalar is a function on the base manifold. A vector is a member of the tangent space of spacetime. A traceless symmetric tensor is a...
-
Orodruin reacted to Steve4Physics's post in the thread Slight Confusion in Introductory Mechanics (Dynamics Problem) with Like.
@Lunar Manatee, note that the SI symbol for the second is 's' not 'sec', so 'm/sec' is incorrect. EDITed to remove surplus information.
-
Orodruin replied to the thread Writing a vector parallel and normal to a unit vector ##\hat n##.On the contrary. It is very reassuring that the components of ##\vec A## add up to ##\vec A##. You should worry if they didn’t! The...