Interesting article on El Reg about the standardisation of the kilogram
Turns out that the kilogram is the last of the SI units to be measured relative to an arbitrary physical object. This is all about the various moves to get away from that standard.
In typical El Reg style it's a pretty nifty explanation of some fairly heavy science, all wrapped up with references to "Glorious silicon globes"...
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wheresthefish Partly filled with wrong, Tue 20 Nov 2012, 23:17,
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Strange... It's a Mass v Weight issue, surely.
A KG is weight, we have Newtons for Mass.
Weight is Mass+Gravitational force. Hence we Weigh less on the moon, but have the same Mass.
I thought 1 KG was 1 litre of distilled water at 3.98 degrees Celsius... at sea level. Or, around 9.8 Newtons...
Stupid Physicists changing their minds.
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zacherynuk @echo off, Wed 21 Nov 2012, 11:53,
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As a physicist myself...
I'd like to correct you.
It's the other way round. The kilogram is a unit of mass, whereas the Newton is a unit of force.
From Newton's second law, F(orce) = m(ass) * a(cceleration). Therefore an object having a mass of 1kg will exert a force (or a weight) of 9.8 Newtons (assuming gravitational acceleration to be 9.8 m/s^2).
The reason for the confusion I believe is that, while we are subjected to gravity, the concepts of mass and weight are, to all intents and purposes, interchangeable. When you step on your bathroom scales, they are in effect measuring the force applied, dividing this by 9.8, and telling you what your mass is. Since gravity has very little variation wherever you are on the Earth, the resulting readout is reliable enough.
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fozberry, Wed 21 Nov 2012, 12:18,
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My cunning ploy
To out the Physicists worked!
Get him boys!
also stand corrected, cheers
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zacherynuk @echo off, Wed 21 Nov 2012, 13:28,
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