Paul,
I've taught astronomy in college and was required to teach those old
fashioned units. But I also taught the metric equivalents, with values
close enough for astronomical work, but "round" enough to be memorable
and useful for mental math. Those "equivalents" are:
300 Mm = light second
150 Gm = astronomical unit (Earth to Sun, 149.6 Gm, more closely)
10 Pm = light year (9.46 Pm, more closely)
30 Pm = parsec (3.09 Pm, more closely)
Jim
On 2011-04-02 1936, Paul Rittman wrote:
Now my next question isn’t really an objection to the metric system, so
much as an interesting application of it. I can see how it would make
sense to use metric-only measurements for earthly measurements. But I’m
still of the opinion that “light-years” are the best measurement for
astronomical distances. I know that the “parsec” is also used, but its
only 3 times longer than the light-year, and not nearly so intuitive (I
mean, to say “light-year” conveys the distance being measured). But I
realize that the concept of light-year is not based on the meter.
So would you folks advise (1) being purist, and quoting inter-stellar
distances as “ultra-giga-multi-meters” or whatever; (2) in parsecs,
which is almost entirely unknown to civilians; or (3) stick with the
term “light-year”? And just as importantly, why?
--
James R. Frysinger
632 Stony Point Mountain Road
Doyle, TN 38559-3030
(C) 931.212.0267
(H) 931.657.3107
(F) 931.657.3108
