> Is there something special that prevents this frozen atom cloud from condensing to an ordinary solid? Yes. The fact they are Fermions and the Pauli exclusio

> Is there something special that prevents this frozen atom cloud from condensing to an ordinary solid? Yes. The fact they are Fermions and the Pauli exclusion principle is what stops them from condensing into a solid. Compared to the effect of the Pauli exclusion principle in solids it is very much a case of same same but very different. In solids there are a limited number of 'states' the electrons can occupy. With a gas of free atoms, there are infinite states for the atoms to be in, however the Pauli exclusion principle still affects the probability field of the atoms with respect to each other. Specifically, the Pauli exclusion principle ensures that no atoms are ever stationary with respect to each other. This stops them from colliding with each other. The best way to think of this is as one of those nbody planet simulations. If you place two stationary planets near each other they start moving together and eventually smash into each other. However, if the planets are moving they just keep zipping around each other, never actually hitting (unless you are very unlucky). The same is true with a cold gas of Fermions. This is often referred to as a 'centrifugal barrier' that keeps them apart.