In September 2007, news reports proclaimed that the kilogram was mysteriously losing mass. Specifically, the reference cylinder, made 118 years ago and kept locked away under glass in France, appears to have lost 50 micrograms when compared with the average of dozens of copies.
Physicists have long recognized this kind of mass drift, however, which is why they have been seeking natural defi nitions for the kilogram [see “Weighty Matters”; SciAm, December 2006]. One possibility for a new defi nition would be the number of silicon atoms in a kilogram of pure silicon; another would rely on electrical power and quantum effects.***[]
Destinasi Wisata Jogya
3 years ago
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