5 ms·
The correct way to define a kilogram would be N number of molecules of Carbon (pick your favorite isotope) at relative speed = 0.
by ye 13y ago
The correct way to define a kilogram would be N number of molecules of Carbon (pick your favorite isotope) at relative speed = 0.
- berntb 13y agoWhich type of C molecules? I think you want to say "X mol of Y. Weight measured in a vacuum, which necessitates an Y with very low evaporation."? Since it isn't done like that, I assume it isn't easy to find an Y which is both easy to measure exactly and to keep pure. (I have a smattering of organic chemistry but no inorganic, so any more opinions from me would be without value.) Edit: Other people here talk about Si. We can keep that clean, at least (see electronics).
- yk 13y agoThey try it, the problem is that you can compare mass better than you can count molecules. So one of the approaches is, to manufacture a Si sphere as perfect as possible and calculate the mass from the radius and the properties of Si crystals. As far as I know, this had no practical results, except cool photos of strangely rendered looking spheres. [1] http://www.theepochtimes.com/n2/images/stories/large/2011/03/27/10301_big_2.jpg http://www.theepochtimes.com/n2/images/stories/large/2011/03... [2] http://www.ptb.de/cms/en/themenrundgaenge/hueterindereinheiten/das-si/avogadro.html http://www.ptb.de/cms/en/themenrundgaenge/hueterindereinheit...
- shocks 13y agoI believe they've been trying to do this with silicon.