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A bosenova or bose supernova is a very small, supernova-like explosion, which can be induced in a Bose–Einstein condensate (BEC) by changing the magnetic field in which the BEC is located, so that the BEC quantum wavefunction's self-interaction becomes attractive. In the particular experiment when a bosenova was first detected, this procedure caused the BEC to implode and shrink beyond detection, and then suddenly explode. In this explosion, about half of the atoms in the condensate seem to have disappeared from the experiment altogether, remaining undetected either in the cold particle remnants or in the expanding gas cloud produced. "The 'missing' atoms are almost certainly still around in some form, but just not in a form that we can detect them in our current experiment," Carl Wieman told SPACE.com. "The two likely possibilities are that they have formed into molecules of two rubidium atoms stuck together, or they have gotten enough energy from somewhere to fly away fast enough that they are out of our observation region before we look for them."〔(Space.com article discussing 'Bosenova'. )〕 Under current quantum theory, this characteristic of Bose–Einstein condensate remains unexplained, because the energy state of an atom near absolute zero appears to be insufficient to cause the observed implosion. However, subsequent mean-field theories have been proposed to explain the phenomenon. Although the total energy of the explosion is very small, it appears very similar to a tiny supernova, hence the term 'bosenova' - the nomenclature is also partly a play on the Brazilian music style, bossa nova. The bosenova behaviour of a BEC may provide insights into the behaviour of a neutron star or a pulsar, as well as in quantum theory in general. ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Bosenova」の詳細全文を読む スポンサード リンク
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