Dear Terry, Thanks for the technique of doing an instant SI survey; I hadn't thought of doing it that way.
On the issue of which is the 'correct' density unit, if asked, I would plump for kilogram per cubic metre as it is the coherent SI unit. The unit grams per cubic centimetre is technically a 'prefixed' unit, even though it doesn't have a prefix before grams, so it is not coherent. I regard grams per cubic centimetre as part of one of the old metric systems. Cheers, Pat Naughtin LCAMS Geelong, Australia -- on 26/3/04 10:04 AM, Terry Simpson at [EMAIL PROTECTED] wrote: > James Wentworth wrote: > >> the average densities of planets and asteroids are >> [...] in terms of grams per cubic centimeter. > > I was sufficiently interested in this to try a crude google measure.... > > Google scores: > planet density kg/m = 7,820 > planet density g/cm = 9060 > > Given that the web is US dominated, it is interesting to try a Google > country specific search: Pages from the UK (www.google.co.uk) > planet density kg/m = 501 > planet density g/cm = 323 > > > >> In addition, in radio astronomy the shorter radio wavelengths >> are expressed in centimeters (for example, the famous >> 21.6 cm "water hole" frequency often used in radio searches >> for signals from other civilizations). > > seti frequency water = 7,600 > seti wavelength water = 2,340 > > Google country specific search: Pages from the UK (www.google.co.uk) > seti frequency water = 287 > seti wavelength water = 133 > > So it seems that there is not universal agreement on which units are used. I > don't know if that is interesting to others. >
