They have not only excised the water
cycle, and excised rain from the carbon
cycle, but have excised the whole atmosphere which is the heavy voluminous fluid
ocean of real gas Air
weighting a ton on our shoulders and in its place have empty space with imaginary ideal gas molecules travelling under their own molecular momentum at great speeds through this empty space miles apart from each other bouncing off each other in elastic collisions, no attraction, and so «thoroughly mixing».