A "universe in a test tube" that could be used to assess theories of everything has been created by physicists. The test tube, the size of a little finger, has been cooled to a fraction of a degree above the lowest possible temperature, absolute zero, which is just over 273 degrees below the freezing point of water. Does one of these test tubes hold a baby Universe? Inside the tube an isotope of helium (called helium three) forms a "superfluid", an ordered liquid where all the atoms are in the same state according to the theory that rules the subatomic...