Invention Allows Humans to Breathe Like Fish

Live Science ^ | 6/6/05 | Bill Christensen

[lilylangtree]

Shades of Irwin Allen.

[velocityguy]

Israeli scientists continue to amaze me!!!

[Puppage]

[Paradox]

That was one of my favorite movies growing up! It evoked alot of emotions in my young brain. Wonder, excitement, and sadness....

[Tallguy]

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.

[Tuba Guy]

[Dahoser]

Paging Bobby Ewing. Mr. Bobby Ewing please pick up the white courtesy phone outside the dreaming shower.

[Puppage]

That was one of my favorite movies growing up!

Mine, too!

[VaBthang4]

"It consists of a reservoir of thick iron plates..." ...thus enabling the wearer to actually walk on the ocean floor.

[Ursus arctos horribilis]

PETA will be PO'ed at robbing oxygen from the fishes.

[massgopguy]

I like the invention that allows people to drink like fish. It's from Holland and comes in a green bottle.

[zek157]

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.

[general_re]

I call bulls***. Seawater is typically less than 10 ppm for oxygen content - if you're going to match the normal proportion of the atmosphere and feed a diver 21% oxygen by volume (go below 16.5% and you'll black out), then for a normal tidal breath of 500 ml, it'll have to contain 105 ml (at 1 atm) of oxygen per breath. Typical resting respiratory rate for adults is maybe 15 breaths per minute, so you have to come up with 1575 ml of oxygen per minute.

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 ;)

[over3Owithabrain]

1) Children suicide bombers;

2) Rocks as bullets;

3) Man-camel reproduction

[Ships of Wood, Men of Iron]

I like the general idea of this general_re calculation, but a similar calculation would seem to show that large fish (e.g., large sharks) could not exist (when it uses its muscles, it would need too much oxygen).

[general_re]

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 :)

[Anvilhead]

This post contains all the things I love about the posts on FreeRepublic.

Nice, concise and humorous.

Plus all of us who received woefully inadequate public school educations can grasp the science involved.

Thanks

[general_re]

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 ;)

[HamiltonJay]

Decrease the pressure - gas dissolved in the liquid releases the gas.

What Editor/Proof-reader let that sentence get to print?