Originally Posted by MickeyMouse
The problem really goes back to when the word 'space' was created to refer to stuff outside the atmosphere, which was coined long before they knew the nature of the atmosphere or the universe. Given the opportunity the rewrite the dictionary, I don't think there should even be a distinction between what's up there and what's down here. Gas pressures simply vary throughout the universe because of various physical phenomena. Even the regions of Earth's atmosphere shouldn't be labeled since they are constantly variable. I guess they figured it was too much effort to change hundreds of years of nomenclature and decided to just pick an arbitrary number and be done with it.
Hmm I'd like to dispute that commment, as we don't know the nature of the atmosphere or the universe, we simply think we do.
A lot of the science, especially astrophysics and the like, is based on hypothetical (possibly the wrong word there, think I'm looking for the word hypothesis) ideas and the little we know of the rock we live on and the data gathered by the few probes we have sent out. We apply the little we know to other planets and the rest of the universe and assume we are correct. Because what works here must work elsewhere in the universe.
Even dark matter is just a theory.
And with a hypothesis you should be able to test it, to prove or disprove it's claims. You can do neither with the majority of astrophysics.
It's the same with the Dinosaurs, scientists claim they had x colour skin, mostly based on that of reptiles of today, but really they don't have a clue. How could they, we have not yet found any fossilised skin (to my knowledge) which could tell us what colour they were!
But yeah it is time for a re-write of the dictionary.