(Left) APS/Carin Cain; (Right) Courtesy P. Bruno/ESRF

Figure 1: (Left) In a spin-$1/2$ or other two-level system, any state can be built from a superposition of a spin-up and spin-down state (blue arrows). This superposition corresponds to a point on a unit sphere, defined by the vector $n$. (Right) Planar projection of the north hemisphere of a spherical representation of Majorana stars for a spin $J=25$. The cloudy regions represent the probability distribution for the spin wave function. In Bruno’s picture, this probability distribution is analogous to the density of a classical gas that is repelled from the Majorana stars.