Dropping a home computer into a vat of liquid would wreck it.
Yet, some operators of supercomputers are submerging their
machines in liquids, without causing any apparent damage, to
keep them from overheating.  Advocates say so-called immersion
or submersion cooling could solve one of the biggest challenges
of the digital economy: reducing the air-conditioning bills and
environmental strains of the power- hungry servers and
supercomputers that crunch ever-rising mountains of data.  A
prototype supercomputer at the Tokyo Institute of Technology,
which is submerged in a tank of mineral oil, was named in
November in an industry ranking, the Green500, as the most
energy-efficient machine of its kind. The computer, called
Tsubame KFC, is 50 percent more powerful than an older
supercomputer at the institute but uses the same amount of
energy.  "The university administration said, 'You're not going
to get any more power,' " said Satoshi Matsuoka, the project
leader. "But we still wanted more performance."  Japan is