How the Diving Bell Opened the Ocean's Depths
Imagine sitting on a narrow bench inside a dark room. Your feet are dangling into a floor of water. You’re vaguely aware of the room moving. Your ears start ringing. If you move too much, you feel the room sway, which could bring the floor rushing in to fill it. You take a breath and dive down, swim outside the room, groping the water, looking for its bottom, reaching for something valuable enough to take back with you.
If you’ve ever pushed an upside-down cup into water, reached inside, and found it still empty, you’ve encountered a diving bell. It’s a simple concept: The water’s pressure forces the air, which has nowhere else to go, inside the “bell.” Once people realized that trapped air contains breathable oxygen, they took large pots, stuck their heads
