And in only one case is a bosenova possible, the extremely cold one. Bosenova is a rather stupid name though, "nova" implies huge amounts of energy, while the energy "released" here seems to be rather smaller than that of a candle flame.Chelle wrote:True, and in both case the result of the experiment was BEC.Mailo wrote:The link you gave speaks of a BEC of magnons. A magnon is not an atom, but an excitation state of the electrons in an atom. The bosenova experiment dealt with a BEC of atoms, which needs 10^-7K.
Er ... you seem to have misunderstood something fundamental about BEC. Atoms can only form a BEC if they are bosons (which means a spin of 1,2,3,... , as opposed to fermions, which have a spin of 0.5, 1.5, 2.5 etc) to start out with.Chelle wrote:No. In the case of "ice" you can say it is "water" because it are water-molecules, but in this case the composition of the atoms is changed into something new; Bose-Einstein Condensate, made out of bosons.Mailo wrote:And no, an atom is still an atom even if it is part of a BEC. A BEC is created by cooling down a cloud of atoms until you get the phase transition to BEC, but you still have the same bunch of atoms, just with different behaviors.
An atom of Helium4 is a boson (2 neutrons, 2 protons, 2 electrons, each with spin 1/2, combine to give a full integer value for the spin. An atom of Helium3 is not a boson, but a neutron (the spins of 1 neutron, 2 protons and 2 electrons cannot combine for a full integer value, but only to something.5).
A cloud of He4-atoms can form a BEC if they are cooled down (but they still remain atoms of He4!), while a cloud of He3-atoms will not.
I read the link you gave for the conversion of detector into BEC and ... no. Particle collisions are in no way whatsoever similar to laser cooling.
I don't quite understand why you linked the two wikipedia pages. Of course you cannot calculate conservation of energy using Newton and the Coriolis force ... you need to take relativistic effects into account.