LY and AU

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Starfighter
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With us: 22 years 8 months
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LY and AU

Post #1by Starfighter » 30.07.2002, 08:05

What's the difference between LY and AU?

Thank you
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Sum0
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Post #2by Sum0 » 30.07.2002, 08:30

AU - astronomical unit - the distance from the Earth to the sun. It takes roughly eight minutes for light to travel 1 AU.
LY - light year - the distance light travels in one year. For example - Alpha Centurai is about 4 light years away, and light from it takes 4 years to reach here. All nice and simple.
"I have been asked, 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question."
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chris
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Post #3by chris » 30.07.2002, 17:56

Also, there are roughly 63000 AU in one light year . . . The nearest star to the Sun is just over 4 light years away, or 250000 times the Earth-Sun distance.

--Chris
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