Spin of a Particle?

[Anchovyforestbane]

If, as one might understand, the conceptualization of tangible substance begins to denature on the scale of elementary particles, then the idea of these quantum charge disruptions having angular momentum doesn't make very much sense. What exactly is it that's "spinning" in a subatomic particle's angular momentum, and how specifically does it effect the rest of nuclear physics?

Additionally, certain wavelengths of light instantly reverse the spin of rubidium molecules. What could be the reason for this?