If you've never taken physics courses (or stayed at a Holiday Inn) you may find this stuff confusing.
That's okay; a lot of physics principles, especially quantum physics, seem counterintuitive.
Questions should be directed to the pros; I have only a rudimentary knowledge of physics.
Here's the info for the above image:
This figure shows two-dimensional false color images of lithium atom clouds. Lithium has two stable isotopes, one of which is a boson (lithium-7), the other of which is a fermion (lithium-6). Bosons and fermions are the two fundamental types of quantum particles found in nature, and are distinguished by their contrasting behavior when in the quantum regime. The atom clouds are shown at three different temperatures: 810, 510 and 240 nano-Kelvin. One nano-Kelvin is a billionth of a degree above absolute zero, which is -460 degrees Fahrenheit. As the temperature gets colder, one can see that the boson gas, shown on the left, coalesces into a compact cloud, while the size of the fermion gas stabilizes at a specific size. This illustrates the principle of Fermi degeneracy, in which the fermions cannot condense further, due to a law of quantum mechanics--the Pauli exclusion principle--that keeps identical fermions from occupying the same space at the same time. The same effect stabilizes white dwarf stars against collapse under their own gravitational attraction.
"Accept no others"
(The physics always seems to make more sense after a few...)
Great find, as always!