21 Apr
2002
21 Apr
'02
4:52 a.m.
At 07:35 PM 20/04/2002 +0100, Tony Duell wrote:
Haven't been paying too much attention to the thread, but I have to chime in
that astronomers don't use the SI (aka MKS (meters, kilograms, seconds))
standard units, but use CGS (centimeter, gram, seconds) based units.
Of course, astronomers always have too many zeros. It doesn't really
matter if a parsec is 3.09x10^18 cm or 3.09x10^16 m.
Where is does get confusing is electric charge. In CGS, the charge of
an electron is 4.8x10^-10 electrostatic units (e.s.u.). An e.s.u. is
one g^(1/2) cm^(3/2) s^(-1).
Eric
That does _NOT_ explain why the base unit is
called the kilogram (it's
the name I am objecting to, and the way that multiples/submultiples are
named [1]).
My understanding for using the Kg rather than g is that it cuts down on the
number of zeros needed. Most real world things we weigh are a more Kg like
than g. For example, a VAX-8800 might weigh 400Kg, which is 400,000g
(there's a good chance of losing one of those zeros).