Angular momentum can accompany nonrotational motion.
Spherical tensor form of the Zeeman Hamiltonian for multielectron atoms has been reduced by utilizing the unreducible tensor theory and the angular momentum coupling theory.
As it did, angular momentum became important.
That's called conservation of angular momentum.
But the original star's angular momentum is preserved.
What's neat is that they can maintain angular momentum indefinitely.
It's a physics toy that demonstrates angular momentum, potential energy, and kinetic energy.
More angular momentum means she can make more turns before needing to replenish what was lost to friction.
更多的量意味着 她可转更多圈 ──在因摩擦力损失量，需再补充之前。
And except for what's lost to friction, that angular momentum has to stay constant while the dancer is on pointe.
Take quantum vortices, which are basically whirlpools of angular momentum in materials like superconductors and superfluids, giving them strange properties.
It seems to be able to right itself by flipping in the air without pushing off anything first, which would contradict the law of conservation of angular momentum.
In order to conserve angular momentum, her angular velocity, the speed of her turn, has to increase, allowing the same amount of stored momentum to carry her through multiple turns.