| One is the puzzle of why there are three and only three generations of fermion, given that the second and third generations seem almost redundantly similar to the first, except for their higher masses and shorter lifetimes. |
| For instance, the proposed superpartner of the electron, a fermion, is called the selectron, and would be a boson. |
| The photon, a boson, has a fermion partner called the photino. |
| The duality relations between the unitary and quasispin algebraic structures for the boson and fermion systems are extended to mixed boson-fermion system. |
| Unfortunately, particle physics predicts that any particle that has chirality cannot have mass, so a massive chiral fermion is a contradiction in terms. |
| When a fermion is transformed into a boson and then back again into a fermion, it turns out that the particle has moved in space, an effect that is related to special relativity. |
