"It will happen," Captain
Cousteau was saying. "Surgery will affix a set of artificial gills to
man's circulatory system-- right here at the neck-- which will permit
him to breathe oxygen from the water like a fish. Then the lungs will
be by-passed and he will be able to live and breathe in any depth for
any amount of time without harm.
"Do you realize what that will
mean? He will be able to observe, train, cultivate, and exploit the
seas at first-hand. Maybe the first man will be an undersea farmer, or
miner, or rancher. Maybe just a scientist. At any rate, there will be
no depth-time barrier, we know that. When his duties are done, he will
be rehabilitated to air breathing by more surgery. It will happen, I
Captain Jacques-Yves Cousteau
Cousteau pretty much hit the nail on the head when he talked about
gills some sixty years ago. You're not going to get very far
under the sea if you insist on such old-fashioned tastes as breathing
air. You have to move with the times and start sucking
liquid down your lungs.
But scientists are an observant lot and they noticed pretty quickly
that when people tried breathing water they ended up very dead.
So, in the 1960s they tried a different liquid: oxygenated
fluorocarbons. These made for really cool demonstrations where
you could stick a mouse in beaker of liquid and it would stay alive--
cheesed off, but alive. On closer examination,
however, the fluorocarbons
weren't as neat a solution as imagined. First, you have to
oxygenate the liquid anyway, so the problem just gets shifted down a notch.
And second, trying to breathe even an oxygenated liquid, isn't easy.
The human lungs aren't designed to pump liquid and the fluorocarbons
didn't need to just bring in oxygen, but remove CO2, which
they were rather poor at.
Also, trying to get prospective volunteers to suck in a lungful of
liquid resulted in what is known as "consumer resistance."