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And here I thought that the gram was defined by one cubic centimeter of pure water at 4°C.
by spc476 16y ago
And here I thought that the gram was defined by one cubic centimeter of pure water at 4°C.
- kragen 16y agoThat was the idea, but they immediately made a prototype kilogram mass in 1799 when they came up with that definition, and it turns out that it was off by about 25 ppm, and we've been working from that prototype ever since — so water only has that density to four significant figures.