Dave wrote:
On Mon, 28 Nov 2005 02:18:04 GMT, Gary said:


Then you should know that your lungs are not going up the hose!


That's not the issue. Your claim is that if the hose is not reinforced, it
will collapse, sealing the air below it, including the air in your lungs.
Think of a thin rubber tube, or a plastic bag, you can't submerge them
at all without them collapsing.

I suggest a small experiment. Take a child's balloon and puff it up to just
ambient pressure so the rubber's stretch isn't a factor. Then take ahold of
the point opposite the inflation tube, hold the inflation tube shut, and put
the balloon under water, with the inflation tube up. Unseal the inflation
tube while holding the balloon at the opposite (now bottom) point with the
other hand. If your theory is correct, the inflation tube will be sealed by
water pressure, and the air will remain in the balloon.

To simulate your lungs, the balloon would have to be held closed at the
mouth of the inflation tube (your throat), not oppsite it and protected
by a cage (ribs). How do you think free divers work?
Wanna bet that will happen?