Sparse Air (atmosphere)

The air is extremely diluted. DILUTED IN WHAT?! Before I can stop to think, I realize that the air is very sparse. The humidity starts to evaporate incredibly fast from all plant life. It feels far colder than anything I would have imagined. 40 degrees is like -15, because the heat goes away so quickly. The winds are incredible. The clouds are wind swept and travel quickly in various directions at once. Water cohesion is not really possible as it is on Earth. Chemical bonds are no longer the same. I realize that Earth's atmosphere is really an ocean, and we don't even realize that we live under something incredibly terrifying. Where is the surface of the atmosphere?! Can a fog of air form in space?! If the atmosphere has a surface, then what would it be like if we seen it?! For example, water is condensed, and even though there is such a thing as water vapor, it cannot really be thought of as an extension of a body of water. Instead, water floats in the air, and becomes condensed, forming a boundary between what is only water, and what is water vapor. And the atmosphere...what is that like?! How is it up there?! Air evaporates away into space as far as I know. What does it evaporate into?! If the air, or atmosphere, is like a body of water, then is there not a definitive boundary, at which pure condensed (gaseous) air turns into something different? And if something falls in, will it create ripples and splashes?! Yet I will be ridiculed by the average people, for thinking such crazy things. It is forbidden, right?