Expert: Ed - 1/30/2008

Question
how long does it take sound to travle one mile one the moon?

Answer
Ryan,

If this is for a homework question, your teacher is probably just messing around with your brain.  It's probably a trick question.

You should tell your teacher that sound doesn't travel on the moon, because there is no atmosphere.  Sound needs something to vibrate, such as gases, or even water or rock.  That's what sound IS.  It's just vibrations.  The moon has basically no atmosphere, so sound doesn't travel.  Therefore, sound would never travel a whole mile on the moon, even if it was the sound of a huge nuclear bomb.  The explosion would be completely silent.

Isn't that a spooky idea?  A totally silent nuclear explosion.  Wow.  There would be a mushroon cloud, but no noise.  There would be lots of radiation too, but that wouldn't make any difference, because there's already so much radiation on the moon.

If this is for a homework problem, I think that's what you should say.  That's what I would do, anyway.

Now, if you think about it, what I just said is true for anyplace where there is absolutely no atmosphere.  Right?  Think about it.  Any science fiction movie or TV show that you have ever seen is lying, if they have ANY sound effects when a spaceship gets blown up in space.  If there is no atmosphere, there is no sound.  Period.

Having said that...  

If you want to get really, really technical, there actually might be a LITTLE sound on the moon.  The moon has a tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny, tiny amount of atmosphere, but it is much, much, MUCH thinner than anywhere on Earth, even thinner than the atmosphere at the top of Mount Everest.

If you want to read about the tiny, tiny, tiny (you get the idea) atmosphere on the moon, look at this NASA website.  Scroll down near the bottom, for the part about the moon's tiny atmosphere.
http://lunar.arc.nasa.gov/printerready/science/geologys.html

I hope this is helpful.

Keep Looking Up!
--Ed