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Dave W.
Info Junkie
USA
26020 Posts |
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H. Humbert
SFN Die Hard
USA
4574 Posts |
Posted - 05/12/2007 : 11:45:47 [Permalink]
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While lying in bed at night, often the strangest thoughts occur to people. Last night, I began to consider this question: "Is there a theoretical limit to how long a snorkel can be?"
I figure the human lungs can only move so much air up and down a tube, and if you aren't sucking in enough fresh air, the air at the bottom might become over-saturated with carbon dioxide and prove fatal. But I also have no idea if the recycled air would "collect" at the bottom of the tube, or if there would be enough mixing to keep all the air in the tube breathable.
Then I wondered what it would feel like to try to breath through, say, a 50 foot snorkel. Would the water pressure be constantly trying to force your lips off of the snorkel so it could rush up the tube and equalize the pressure? Or would it make your lips stick even harder to the tube? Or would there be no effect from water pressure?
These are the questions which keep me awake at night. I'm sure someone here (Dave  ) is smart enough to already know the answers.
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"A man is his own easiest dupe, for what he wishes to be true he generally believes to be true." --Demosthenes
"The first principle is that you must not fool yourself - and you are the easiest person to fool." --Richard P. Feynman
"Face facts with dignity." --found inside a fortune cookie |
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Dave W.
Info Junkie
USA
26020 Posts |
Posted - 05/12/2007 : 11:53:50 [Permalink]
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Wikipedia is your friend:The maximum usable length of the snorkel tube is around fifty centimetres (twenty inches). A longer tube would place the lungs in deeper water where the surrounding water pressure is higher and the lungs would be unable to inflate when the diver inhales, because the muscles that expand the lungs are not strong enough to operate against the higher pressure. Snorkels also create what is called "dead air space." When the user takes in a fresh breath, some of the previously exhaled air remains in the snorkel and is recycled into the lungs, reducing breathing efficiency. The greater the volume in the device, the more this problem is magnified. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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H. Humbert
SFN Die Hard
USA
4574 Posts |
 Posted - 05/12/2007 : 12:24:55 [Permalink]
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Originally posted by Dave W.
Wikipedia is your friend:The maximum usable length of the snorkel tube is around fifty centimetres (twenty inches). A longer tube would place the lungs in deeper water where the surrounding water pressure is higher and the lungs would be unable to inflate when the diver inhales, because the muscles that expand the lungs are not strong enough to operate against the higher pressure. Snorkels also create what is called "dead air space." When the user takes in a fresh breath, some of the previously exhaled air remains in the snorkel and is recycled into the lungs, reducing breathing efficiency. The greater the volume in the device, the more this problem is magnified.
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Thanks, Dave. While I did try Googling a bit, it never occured to me to check Wikipedia.
Wow, only 20 inches, huh? That's shocking to me. I figured one could at least walk around on the bottom of a pool's deep end with a long enough snorkel. Shows what I know.
Now...where do babies come from?
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"A man is his own easiest dupe, for what he wishes to be true he generally believes to be true." --Demosthenes
"The first principle is that you must not fool yourself - and you are the easiest person to fool." --Richard P. Feynman
"Face facts with dignity." --found inside a fortune cookie |
| Edited by - H. Humbert on 05/12/2007 12:26:33 |
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filthy
SFN Die Hard
USA
14408 Posts |
 Posted - 05/12/2007 : 15:59:59 [Permalink]
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| Now...where do babies come from? |
Please be more specific; what kind of babies?
For example, Suger Babies come from a candy factory, as do Baby Ruths.
"It's your baby." comes from someone in authority giving you a job nobody else wants, and "Oh, baby!" is usually an adult.
It's all very confusing. 
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist! 
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Hawks
SFN Regular
Canada
1383 Posts |
Posted - 05/12/2007 : 17:01:18 [Permalink]
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Originally posted by H. Humbert
Now...where do babies come from? |
As the 4-year-old daughter of a friend once pronounced it: the bagina. |
METHINKS IT IS LIKE A WEASEL
It's a small, off-duty czechoslovakian traffic warden! |
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JohnOAS
SFN Regular
Australia
800 Posts |
Posted - 05/13/2007 : 04:35:17 [Permalink]
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Originally posted by H. Humbert
Wow, only 20 inches, huh? That's shocking to me. I figured one could at least walk around on the bottom of a pool's deep end with a long enough snorkel. Shows what I know.
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I haven't read the wikipedia article yet, but was thinking about this myself recently, for a more mundane reason.
I want to give the walls of our pool a good scrub, and constantly swimming up and down is quite inefficient. I was thinking of making my own snorkel, I need about 1.5m at the deep end.
I imagined that the volume of air would be the main problem, that is, you'd be mostly re-breathing your previous exhalation, but figured I could counter that with two tubes and a couple of cheap valves I have on hand. It'll be interesting to see how the pressure goes though, I didn't think that would be as big a deal as the article seems to suggest. |
John's just this guy, you know. |
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Boron10
Religion Moderator
USA
1266 Posts |
Posted - 05/13/2007 : 08:20:05 [Permalink]
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Originally posted by JohnOAS
I haven't read the wikipedia article yet, but was thinking about this myself recently, for a more mundane reason.
I want to give the walls of our pool a good scrub, and constantly swimming up and down is quite inefficient. I was thinking of making my own snorkel, I need about 1.5m at the deep end.
I imagined that the volume of air would be the main problem, that is, you'd be mostly re-breathing your previous exhalation, but figured I could counter that with two tubes and a couple of cheap valves I have on hand. It'll be interesting to see how the pressure goes though, I didn't think that would be as big a deal as the article seems to suggest. |
Honestly, JohnOAS, you could rig a snorkel assembly with two hoses and a check valve on each, giving you a Y-shaped assembly, with an in tube and an out tube.
The water pressure pushing on your lungs would still be a problem, but that is based mainly on the strength of your lungs. SCBA tanks will give you air that is under pressure, mitigating that problem; however, with a very long snorkel you will never quite feel like you took a deep enough breath. Depending on what you're used to, that will cause you to panic, or just to pass out.
So, I'd say it would be an interesting project, but make sure you have somebody nearby who knows CPR before you decide to test it, eh? |
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JohnOAS
SFN Regular
Australia
800 Posts |
Posted - 05/13/2007 : 19:08:36 [Permalink]
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Originally posted by Boron10
Honestly, JohnOAS, you could rig a snorkel assembly with two hoses and a check valve on each, giving you a Y-shaped assembly, with an in tube and an out tube. |
Pretty much exactly what I had in mind.
Originally posted by Boron10
So, I'd say it would be an interesting project, but make sure you have somebody nearby who knows CPR before you decide to test it, eh?
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Damn, that means I've also got to finish the IP video distribution stuff for getting the pool video to the living area. Mind you, my wife seeing me floating is no guarantee she'll do anything about it...
The water temp's also dropping, so I may not feel inspired to do it anytime real soon.
Just another project to add to the long list of those languishing at 80-95% completion because something more interesting came along...
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John's just this guy, you know. |
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HalfMooner
Dingaling
Philippines
15831 Posts |
Posted - 05/13/2007 : 23:51:04 [Permalink]
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I had my first bike spill in about 38 years tonight. I went out for dinner to Cameron's, an English pub/restaurant about a mile away, riding my electric scooter. I had one of their greasy New York steaks, with cole slaw, and a Boston Cream for dessert. I had exactly two draught Guinesses to wash the entree down (I've checked the receipt). I always, strictly, ride on the shoulder of the highway. My two-wheeled electric scooter is capable of only slow speed, less than that of a sprinter. Legally, my Expresso 2 is a bicycle.
Half an hour ago when I got home, I had a bleeding scrape on my left hand, scratches on the left side of my helmet, and vague memory of my scooter slipping on grass as I drove along the verge and onto the shoulder, when starting my trip home. My bike has a cracked trunk box, and minor scratches. My hand is a little sore, but apparently has no broken bones. I'm certain nobody hit me, and that I left no flaming wreckage and burning victims behind me. My bike helmet has tell-tale scratches on the left side, and both my left knee and my left elbow are very slightly sore. I think my wheels just slipped out from under me on the slick, sloping grass verge. The dumb choice of riding over the grass on a dewy coastal night may have been alcohol-related, and certainly my slow reactions thereafter were.
I am not noticeably mentally impaired at two glasses of beer, have no speech slurring, etc. But apparently since my stroke three years ago, my coordination goes to hell at just two beers now. I doubt I was at the legal blood alcohol limit for motor vehicle drivers. I don't drink enough, or often enough, to have much idea of my capacity, but I have decided that I cannot drink more than one drink anymore if I expect to walk or ride afterward.
Does anyone here know about this kind of side-effect of a stroke? They never gave me the full stroke brochure. This was a shocker to me, once I got the bike into my carport and was no longer too dazed to be aware that something had happened. (And yes, I do expect a scolding from Beskeptigal. I'll take it like a good boy. But these kinds of things really do change my behavior.)
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“Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive. |
| Edited by - HalfMooner on 05/14/2007 00:48:39 |
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Kil
Evil Skeptic
USA
13476 Posts |
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Dr. Mabuse
Septic Fiend
Sweden
9687 Posts |
Posted - 05/20/2007 : 12:55:05 [Permalink]
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Originally posted by HalfMooner
Half an hour ago when I got home, I had a bleeding scrape on my left hand, scratches on the left side of my helmet, and vague memory of my scooter slipping on grass as I drove along the verge and onto the shoulder, when starting my trip home. |
Ouch!
I'm glad you're ok though... and I hope you stay ok.
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Dr. Mabuse - "When the going gets tough, the tough get Duct-tape..."
Dr. Mabuse whisper.mp3
"Equivocation is not just a job, for a creationist it's a way of life..." Dr. Mabuse
Support American Troops in Iraq:
Send them unarmed civilians for target practice..
Collateralmurder. |
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Dave W.
Info Junkie
USA
26020 Posts |
Posted - 05/20/2007 : 18:33:28 [Permalink]
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Originally posted by Kil
Some more picts from the dinner: |
Clever how you got yourself into those picts by hovering over the man. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Cuneiformist
The Imperfectionist
USA
4955 Posts |
Posted - 05/20/2007 : 19:00:56 [Permalink]
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| Geez, [b/]HM[/b]-- do you really think that after a few drinks, you'd black out and not recall something like that? I guess the evidence is compelling, but it's distressing. Do you know if the situation can improve? What do the Docs think? |
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Kil
Evil Skeptic
USA
13476 Posts |
Posted - 05/20/2007 : 20:27:24 [Permalink]
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Originally posted by Dave W.
Originally posted by Kil
Some more picts from the dinner: |
Clever how you got yourself into those picts by hovering over the man.
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It looks like that doesn't it? Michelle and I had just come back from having a smoke and I started for my seat when the guy who was taking the picts blocked the way for Michelle. I was waiting for her. This was after dinner. We all chatted until about 10:00. The other thing was Michelle told me not to bring a camera. She thought it would be tacky... |
Uncertainty may make you uncomfortable. Certainty makes you ridiculous.
Why not question something for a change?
Genetic Literacy Project |
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The water cooler, part 2
Topic Locked
