I've always wonder what keeps the atmosphere up ..
December 31, 2006 10:05am CST
It's a strange thing .. but the atmosphere stays up in the sky .. yet gravity pulls everything down towards the centre of the earth ... so why doesn't the air just 'fall down' ??
• United States
31 Dec 06
that's a good question. Energy from the sun excites the air molecules and they'd all fly off into space if it weren't for gravity. Think of it like the ocean. The water doesn' all settle to the bottom. The same is true of air. we have an ocean of gasses above us and we're on the bottom of it.