please hurrryy!
2007-09-25 09:34:34 · 10 answers · asked by dancinn4lifee_07 1 in Science & Mathematics ➔ Astronomy & Space
For the same reason we don't measure distances between cities in millimeters. You get numbers that are way too big to be practical.
Doug
2007-09-25 09:42:38 · answer #1 · answered by doug_donaghue 7 · 3⤊ 0⤋
Even with scientific notation, there isn't enough room on the paper. "1 AU" takes up a lot less space than "93,000,000 miles" or even "9.3 * 10^7 miles". Also, "1 light year" or "1 ly" is easier to write than "5,865,696,000,000 miles" [or 186000*60*60*24*365]. And, no, I am not even going to try and type out how far a parsec is in miles or km. Using astronomical terms is simply more efficient and time saving. Nothing is close in space. The closest natural thing to the earth is our Moon and even that is over 250,000miles away. About the only thing that one could easily write out the numbers for are man made satellites. Those are *just* miles up. [Okay, let's not get technical and we'll just ignore inter-planetary missions like Cassini, Galileo, and especially Pioneer and Voyager :P]
2007-09-26 14:43:02 · answer #2 · answered by quntmphys238 6 · 0⤊ 0⤋
Because those are so small compared to the distances involved. Measuring the distance to the stars in miles is like measuring the distance from New York to Tokyo in inches.
2007-09-25 10:41:21 · answer #3 · answered by campbelp2002 7 · 0⤊ 0⤋
Because distances between celestial bodies in space are so far away you would have to say 70000000000000000000000000 miles between this star and that star, and that comet is 4000000000000000000000000000 miles away from that asteroid and things like that.
It is much easier to say things like, those two planets are 5AU (Astronomical Units) aparts, or maybe 17 light years apart, then to waste space and paper putting down dozens of zeros.
2007-09-25 09:46:20 · answer #4 · answered by Anonymous · 1⤊ 0⤋
Because there are so many of them that they don't make a very good unit. Nobody outside of the U.S. uses miles for anything, astronomical or otherwise.
Light years, in particular, have significance in other ways - if something is 100 light years away, you are seeing it as it was 100 years ago.
2007-09-25 09:40:48 · answer #5 · answered by laurahal42 6 · 1⤊ 0⤋
Actually, although you typically read stories about astronomy talking about parsecs and light years and redshifts, astronomers use CGS units in papers - that means we use centimeters. Sure, it's a lot of centimeters. But it's traditional.
2007-09-25 09:59:18 · answer #6 · answered by eri 7 · 0⤊ 0⤋
By using such "small" measurements, it's hard to really measure how far away certain cellestial bodies are. Therefore we can use parsecs, AUs, lightyears, etc. to make the numbers much more workable.
2007-09-25 09:43:38 · answer #7 · answered by Anonymous · 1⤊ 0⤋
Because it gets cumbersome to deal in numbers with magnitudes of "trillions", "quadrillions", etc.
Therefore, more convenient units were adopted, like AU and light-year.
2007-09-25 09:37:20 · answer #8 · answered by tastywheat 4 · 1⤊ 0⤋
i wish i knew but do u go to hp or ov?
cuz your questions are just like my science homework!
so e-mail me and tell me!
sorry i don't have a answer..... :(
2007-09-25 12:47:08 · answer #9 · answered by Malloy. 1 · 0⤊ 0⤋
space is way to large they use parsecs(sp?)
2007-09-25 09:39:32 · answer #10 · answered by unuszak 2 · 0⤊ 0⤋