Historical information on density

AI Thread Summary
Historical information on density reveals that it cannot be added linearly, as demonstrated by the example of a mixture containing 10% of one material and 90% of another. The discussion seeks to identify the first individual to understand this principle. Archimedes' Principle is mentioned as a related concept, emphasizing the importance of displacement in determining density. The conversation also clarifies misconceptions about Archimedes' experiments with the king's crown, highlighting the method of balancing weights to assess volume. Overall, the thread emphasizes the complexity of density and its historical context.
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This may or may not be the correct forum to ask this, but let's ask it anyway.

I am looking for historical information on density.
It is so that densities can not be added lineary:
A material containing 10% of material 1 and 90% of material 2 will not have a density of 10% * the density of material 1 + 90% * the density of material 2.

I'd like to know who was the first that realized this.

(any other historical information on density is also welcome).
 
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While it's not strictly speaking density, Archimedes' Principle is related.

http://en.wikipedia.org/wiki/Archimedes
http://physics.about.com/cs/fluiddynamics/g/archimedes.htm

This may get you started.
 
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Aha, I have re-read the site and have to change what I said. He probably did not do the experiment to determine if the kings crown was made of pure gold by simply using the law of the lever and the displacement of water. The problem with that method is that it is too small of a displacement of water when comparing pure gold to gold-silver alloy. To overcome this, he balanced the known gold and the crown on a lever. Then he put the lever into the water. If it remained level, then they both had the same volume. The Crown is quite nice too!
http://www.math.drexel.edu/%7Ecrorres/Archimedes/contents.html
 
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That's a good one. I should have thought of that one. Thanks.
 
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