Re: FW: Dinosaur Weights

[Jonathon Woolf <jwoolf@erinet.com>]

Dinogeorge@aol.com wrote:
> 
> In a message dated 97-08-23 07:09:31 EDT, EDELS@classic.msn.com (Allan )
> writes:
> 
> << "Most animals have about the same density as water."
>  This is about 1000 kilograms per cubic meter. >>
> 
> By definition, it should be exactly 1000 kg/m^3. But it's not. Anybody out
> there know why not? I've been wondering for years.

Temperature and density.  1 cc = 1 ml = 1 g holds exactly for pure H20
at a specific temperature.  I think it's 4 degrees C, but I might be
confusing that with the max-density temperature for water.  Warmer water
is less dense, so 1 g of it occupies slightly more than 1 ml.  Any other
chemical present also changes the density, which is why seawater is
denser than fresh water.  

(In fact, I think that equation may be the current official Bureau of
Standards definition for both liter and gram, but I'm not sure. I know
the meter is defined in terms of wavelengths of a specific frequency of
light.)  

-- JSW