Quote (dro94 @ Oct 21 2016 01:01pm)
air isnt a compound it's composed of different gases. the composition of gas in the atmosphere creates a protective shield that ensures we aren't destroyed by UVC radiation from the sun. you're implying that a shield has to be some physical wall or something. it doesn't.
For anything to be a closed environment - you need to be "inside" of something moving - to shield yourself from the force of the air that results from traveling through that air - like in a car or a plane or a train - you are inside a steel box - the steel around you is what protects you from the force of the air. When you are in a train - does the air around you shield you from the air on the outside, or does the fact your inside a metal box?
According to Heliocentricity - the earth is moving and moving mind numbingly fast, the reason the air around it is not sucked into the vacuum of space is because the air is attracted /sucked in by Earths' gravity) [and so is the water btw]
but a gas like air cannot also be a shield to enclose something - like ever.