Kilogram's Future Hangs In The Balance

Re:Kilogram's Future Hangs In The Balance by abrahamsen on Thursday August 20, 2009 @08:30AM (#774854)

What is the problem with defining the kg in terms of the already existing atomic mass unit?

See http://en.wikipedia.org/wiki/Atomic_mass_unit

The atomic mass unit is already associated with the mole, which is in SI.

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Re:Kilogram's Future Hangs In The Balance by sethg on Thursday August 20, 2009 @10:41AM (#775128)

I think the trick is to define the kg in terms of something that is not only a universal constant but can also be practically measured.

If I redefine the gram as the mass of 6e23 atoms of carbon-12, and you give me a big pile of carbon-12 and say "what's the mass?" and I can't count exactly how many atoms are in the pile, then my definition isn't very useful.

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Re:Kilogram's Future Hangs In The Balance by tokenadult on Thursday August 20, 2009 @08:39AM (#774868)

There have been attempts to redefine the mole.

http://www.iop.org/EJ/article/0026-1394/46/3/022/met9_3_022....

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