Absolute zero is no longer absolute zero

Scientists have rewritten the known laws of physics after hitting a temperature lower than absolute zero. Physicists at the Ludwig Maximilian University in Germany created a quantum gas using potassium atoms, fixing them in a standard lattice group using magnetic fields and lasers. When the magnetic fields were rapidly adjusted, the atoms shifted from a low energy state to their highest possible energy state. That rapid transition — along with the laser trapping field that kept the atoms in place — allowed the temperature of the gas to dip "a few billionths of a Kelvin below absolute zero." The intriguing breakthrough could lead to the creation of "new forms of matter" in laboratories, but there are some side effects. Normally a cloud of atoms would be pulled downward by gravity, but some atoms in a group that’s below absolute zero could instead float upwards. Affected atoms in the modified gas also appear to mimic dark energy — hypothetically responsible for the expansion of the universe — by avoiding collapsing in on themselves. via Nature