Posted on 06/06/2005 9:14:07 AM PDT by kiriath_jearim
Invention Allows Humans to Breathe Like Fish
By Bill Christensen
posted: 06 June 2005 09:07 am ET
Alan Izhar-Bodner, an Israeli inventor, has developed a way for divers to breathe underwater without cumbersome oxygen tanks. His apparatus makes use of the air that is dissolved in water, just like fish do.
The system uses the "Henry Law" which states that the amount of gas that can be dissolved in a liquid is proportional to the pressure on the liquid. Raise the pressure - more gas can be dissolved in the liquid. Decrease the pressure - gas dissolved in the liquid releases the gas. This is exactly what happens when you open a can of soda; carbon dioxide gas is dissolved in the liquid and is under pressure in the can. Open the can, releasing the pressure, and the gas fizzes out.
Bodner's system apparently uses a centrifuge to lower pressure in part of a small amount of seawater taken into the system; dissolved gas is extracted. The patent abstract reads:
A self-contained open-circuit breathing apparatus for use within a body of water naturally containing dissolved air. The apparatus is adapted to provide breathable air. The apparatus comprises an inlet means for extracting a quantity of water from the body of water. It further comprises a separator for separating the dissolved air from the quantity of water, thereby obtaining the breathable air. The apparatus further comprises a first outlet means for expelling the separated water back into the body of water, and a second outlet means for removing the breathable air and supplying it for breathing. The air is supplied so as to enable it to be expelled back into the body of water after it has been breathed.
Human beings have been thinking about how to breathe underwater since they started swimming. This long-held desire plays an important part in one of the first great science fiction novels, Jules Verne's 20,000 Leagues Under the Sea.
It consists of a reservoir of thick iron plates, in which I store the air under a pressure of fifty atmospheres. This reservoir is fixed on the back by means of braces, like a soldier's knapsack.
More recently, I distinctly remember an episode of the sixties sf series Voyage to the Bottom of the Sea in which a scientist decides that the best way to breathe underwater is to give himself gills. Alas, once equipped with gills, and fully acclimated to life in the sea, Dr. Jenkins and his associate lie in wait outside the submarine Seaview, converting every diver who emerges from the ship into mermen.
And, of course, everyone remembers the scene in which intrepid Jedi Obi-Wan Kenobi and Qui-Gon Jin don pencil-sized breathing masks to explore the swamp lakes of Naboo in The Phantom Menace. This trick is used again in the most recent Star Wars movie.
Read more at Like a Fish: Revolutionary Underwater Breathing System, or take a look at more inventions from 20,000 Leagues Under the Sea and the Functional Captain Nemo Diving Suit. Also, an excellent recent novel, Starfish by Peter Watts, refers to a "recycler" that can be implanted directly in the diver. Thanks to alert reader Adi for pointing this story out.
Shades of Irwin Allen.
Israeli scientists continue to amaze me!!!
That was one of my favorite movies growing up! It evoked alot of emotions in my young brain. Wonder, excitement, and sadness....
Sounds expensive & maintenance intensive. If it doesn't extend my Bottom Time, I am not interested! Besides, how would this system be superior to the semi-closed rebreather systems available now? If I'm going to break my piggybank that's where I'm going to spend it.
Mine, too!
I like the invention that allows people to drink like fish. It's from Holland and comes in a green bottle.
Hmmm, someone please name 3 modern inventions made by a muslim (besides hijacking aircraft and algebra.
A Nobel prize winners out there besides Arafat?
great culture.
So, bottom line, at 10 ppm you'll need to process 157,500,000 ml of seawater per minute, or 157,500 liters per minute. Now, a fairly high-powered shop vac will suck in 125 cubic feet per minute, or about 3500 liters per minute, so imagine something that sucks in water 45 times faster than a shop vac, take that something and strap it to your back, and that's what we're talking about. And this is a best-case scenario - the minute you have to move or exert yourself or anything, your respiratory rate and oxygen requirements are only going to increase. Hope whatever this thing is, it comes with a hell of an extension cord ;)
Ah, it's much easier for fish - they're heterothermic (cold-blooded), so they don't need to expend lots of energy maintaining a high body temperature, among other things. Nor do they have large brains with the attendant fuel requirements. Etc., etc. - fish have much, much lower oxygen requirements than people, so they're perfectly happy with 5-7 ppm oxygen for their environment, versus the 160,000 ppm your body likes to have :)
Why, thank you. The short version is that seawater just doesn't have enough oxygen in it to make this feasible - not that I can see, anyway ;)
What Editor/Proof-reader let that sentence get to print?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.