“It is easy to forget that you live in the sky – not beneath it, but within it. Our atmosphere is an enormous ocean, and you inhabit it. This ocean is made up of the gases of air rather than liquid water, but it is as much of an ocean as the Atlantic or the Pacific. You may think of yourself as living on the ground, but all that means is that you are a creature of the ocean bed. You still inhabit the atmosphere like a sea creature does the water.”