Breathing from a 30ft. snorkel

[reo]

I like swimming and watching fish. Id love to scuba dive but the equipment and corses are so darn expensive.

Can't this be done more cheap? I took some heavy garden hose and duck taped it to a beach ball and put the other end in my mouth. I put on a fany pak full of steel pieces and walked into the pond in my yard and it worked great. I tried making a mask but it leaked real bad and foged up.

I bet Jeff Foxworthy could use this...

 

[Nemrod]

All right guys, help me out on this would ya?
A guy asked at work today a hypothetical question:
If a person had a 33ft. long snorkel with an exhaust valve on it so that he could exhaust the c02 rather than sending it back up the snorkel, why wouldn't he be able to breathe through it?
I didn't have the answer. Any takers?
Oh, BTW, As I said at the top of the page, this was only a hypothetical question asked to help pass the workday (or evening)........he doesn't really want to do this (I don't think)
I did tell him though, that even though you are not breathing compressed gas from a tank, I believe the effects of surfacing while breathholding would be the same since the air has been compressed by the depth.
Anyway, not a question you folks need to take too seriously, I was just curious how to figure the answer.
Bob

This should have been explained in Basic Scuba.

As an ex educator who taught HS science and after watching people sleep through class because they didn't need to know "science stuff" I would tell your friend to go back to HS and give his diploma back. I no longer teach as a result because I like "science stuff."

The reason we measure regulator performance in terms of parameters such as inches of water for cracking effort, typically around .6 to 1.5 for a quality regulator, is because more than a few inches of water pressure differential and the lungs simply cannot inflate to draw a breath much less at 33 feet, a one atmosphere differential .

If you ran a garden hose to the moon's surface, the moon being at a near vacuum, from the earth's equator and the earth at sea level being approx 14.7 psi, would all of the earths atmosphere suck out to the moon through the garden hose leaving the earth without?

N

 

[captain]

There are stories of hard hat divers being buried in their helmets before check valves were used at the helmets air hose connection point. The check valve is the one most important piece on a surface supplied diving helmet. Something would happen at the surface like the air hose bursting and and the water pressure would literally compress the divers body into the helmet.
I strongly advise anyone trying to disprove that you can't breathe through a snorkel much longer than 18 inches to not attempt to breathe through a hose or pipe at any depth deeper than a couple of feet or you may be fishing your lungs out of it.

This is pretty much basic diving physics and I am very surprised by the lack of knowledge from trained divers.

 

[Splitlip]

Yes, However, a hose may compress with the pressure. However, if you took a rigid piece of PVC pipe that wont compress, I believe it would be the same as if on the surface.

No.

The air in the tube is at 1ATA (surface pressure). For you to create a vacum to move the air to your lungs, your diaphram woule nee3d to overcome the ambient pressure of the water. Your daphragm muscles cannot do that.

We are nature's creatures and nature did not intend for us to breath under water.

Do we understand what causes AGE? It is the massive ambient pressure differences at different depths. It is these pressure changes which makes breathing from a snorkle described impossible. Even try standing in a pool with the snorkle you use when horizontal on the surface and you will feel the difference. Nothing to do with friction.

That is why gas must be pressurized in the cylinders (in addition to added volume) and the delivery pressure is regulated by well, your regulator. Also why with an unbalanced regulator, as you surface with an "empty" tank, you can breath as the ambient pressure of the water falls below the tank pressure.

Do we know why 80 cf of gas lasts longer at 20 ft than 90 ft?

Now I was certified over 30 years ago, but they taught us all of this. I am going to hunt up my daughter's OW PADI book and see if all the gass laws are covered.

I am very surprised at some of the posts.

 

[Diver0001]

As an ex educator who taught HS science and after watching people sleep through class because they didn't need to know "science stuff" I would tell your friend to go back to HS and give his diploma back. I no longer teach as a result because I like "science stuff."

That's low.

his friend is asking the question and no matter how "ignorant" or how naive the question, the mere act of asking it is the most important thing here. Maybe he didn't pay attention in high-school but he's paying attention now.... There is no reason to ridicule him for that! It's no wonder you gave up as a teacher!

If you ran a garden hose to the moon's surface, the moon being at a near vacuum, from the earth's equator and the earth at sea level being approx 14.7 psi, would all of the earths atmosphere suck out to the moon through the garden hose leaving the earth without?

N

Any point to this question that has to do with the question at hand?

R..

 

[Hatul]

Normally the lungs can deal with pressures up to 30-40 cmH2O while 1 psi=70 cmH2O. 14.7 psi is over 1000 cmH2O. If you vented the lungs to 1 atm they would collapse to half their volume and you would not be able to generate enough pressure to expand.

Adam

 

[Arizona_SVO]

If you ran a garden hose to the moon's surface, the moon being at a near vacuum, from the earth's equator and the earth at sea level being approx 14.7 psi, would all of the earths atmosphere suck out to the moon through the garden hose leaving the earth without?

But could I breathe in a pool on the moon with this hose since there is no pressure on my lungs?

Oh and FWIW, I liked the question so I could learn all these cool experiments and how NOT to do them... keep it coming.

 

[Guba]

But in answer to the question about the garden hose to the moon...

I'm assuming, of course, that the question was asked rhetorically. What I think many people (at least many of my flegling students) tend to ignore is the source of the pressure...it comes from the weight of the fluid, whether that fluid is a liquid or a gas. Weight is a function of gravity pulling upon a mass. Therefore, it does not matter what the pressure is at the moon. The air in the tube will not overcome gravity in order to climb the distance to the moon. If it were just a matter of pressure and "vacuum", all earth's atmosphere would head for space.

 

[ScubaSteve]

But in answer to the question about the garden hose to the moon...

I'm assuming, of course, that the question was asked rhetorically. What I think many people (at least many of my flegling students) tend to ignore is the source of the pressure...it comes from the weight of the fluid, whether that fluid is a liquid or a gas. Weight is a function of gravity pulling upon a mass. Therefore, it does not matter what the pressure is at the moon. The air in the tube will not overcome gravity in order to climb the distance to the moon. If it were just a matter of pressure and "vacuum", all earth's atmosphere would head for space.

Oh man.....I was waiting to see if Mythbusters would pick up the challenge

 

[Jax]

Dang, Vondo...you beat me to it.

He's correct. The user of this straw has to do only enough work to raise the liquid about six inches. That's doable, even after accounting for the increased resistance due to fluid friction in the straw itself. If a person would only add another 90 degree connector and a one foot section of straw straight DOWN, the fluid will deliver itself with no effort(as in siphoning) once the straw is filled. However, lifting the fluid vertically another couple of feet would be MUCH more difficult, if not impossible.

Okay, guys, I'm not buying this "can't bring up fluids" at 33".

Have none of you ever siphoned gas out of a car? I had a 6' hose for just such a purpose, and I'm pretty sure the bottom of the truck tank to the gas cap wasn't quite your 3', but it was a lot more than you seem to be talking about.