Do humans live at the bottom of a sea of air?

Yes, humans live at the bottom of a sea of air, as the atmosphere can be thought of as a vast ocean of gases surrounding the Earth. This "sea" consists mainly of nitrogen and oxygen, providing the air we breathe. The pressure and density of the atmosphere decrease with altitude, similar to how water pressure increases with depth in the ocean. Thus, the concept of living at the bottom of an air "sea" is a useful metaphor for understanding our environment.