damp, curvaceous, undulations...oh my!

Geez ladybug, I can't believe your virtually harmless comment. I almost dropped this, but the more I think about it.. the crazier it is.

From wikipedia:

Carbon dioxide content in fresh air varies and is between 0.03% (300 ppm) to 0.06% (600 ppm), depending on location and in exhaled air approximately 4.5%. When inhaled in high concentrations (greater than 5% by volume), it is immediately dangerous to the life and health of plants, humans and other animals. The current threshold limit value (TLV) or maximum level that is considered safe for healthy adults for an 8-hour work day is 0.5% (5000 ppm). The maximum safe level for infants, children, the elderly and individuals with cardio-pulmonary health issues would be significantly less.

These figures are valid for carbon dioxide supplied in "pure" form. In indoor spaces occupied by humans the carbon dioxide concentration will also reach a level higher than in pure outdoor air. Concentrations higher than 1000 ppm will cause discomfort in more than 20% of occupants, and the discomfort will increase with increasing CO2 concentration. The discomfort will be caused by various gases coming from human respiration and perspiration, and not by CO2 itself. At 2000 ppm will the majority of occupants feel a significant degree of discomfort, and many will develop nausea and headache. The CO2 concentration between 300 and 2500 ppm is used as an indicator of indoor air quality in spaces polluted by human occupation.

Acute carbon dioxide toxicity is sometimes known as choke damp, an old mining industry term, and was the cause of death at Lake Nyos in Cameroon, where an upwelling of CO2-laden lake water in 1986 covered a wide area in a blanket of the gas, killing nearly 2000.

From MSDS

>4% by volume in the atmosphere produces labored breathing and is dangerous for even a few minutes of exposure; >12% causes rapid unconsciousness; a few hours exposure at 25% results in death.

Maybe liquid Nitrogen or helium would only be equivalent to holding your breathe.. but CO2 is toxic. So I realize one lb of dry ice in a 20ft x 20ft room is relatively harmless, but you are talking about inhaling it directly over the course of however long you are hitting the hookah. That is going to be way over an average intake of 3000ppm. Now you might argue that when breathing normal air in between hitting the hookah, you are dispelling a lot of excess CO2, but I think your blood is getting elevated toxic levels during the hose sucking parts.

wow fascinating. There is more physics here than just a simple boom. Look at the way the bubble oscillates just after the bottle ruptures. At the time the plastic bottle explodes the internal pressure of the CO2 gas is much higher than that of the surrounding water pressure and the inertia of the gas as it escapes "overshoots" the diameter at which the internal pressure of the gas bubble would be at local equilibrium with the water pressure. The water pushes back in on the bubble and because the gas volume is compressible (and water is not) it collapses; AHH but it "overshoots" the equilibrium point again this time in the opposite direction! Now the gas pressure in the bubble is higher than the surrounding water pressure again so it expands and it goes on like this expanding and contracting. But the bubbles are bouyant! So they are rising as this osclillation (which is being damped out by internal friction of course) is occurring and as they rise the external water pressure the bubbles "feel" is less and less so the oscillation frequency goes up as they rise. Also if you look closely you can see that it is only the pressure waves from this oscillation that cause the surface of the water to "spall" and the actual gas does not reach the surface until the very end. So you hear three distinct noises, first the initial shockwave of bottle rupture, then oscillating water spall at the surface caused by pressure waves from the bubble oscillation and THEN the bubbles of gas breaking at the surface sloshing the water around.

My sister (Uptown) and I (Metairie) had minor damage. Three aunts Uptown were not so lucky. One had 27 inches standing salt water in her basement. Another had water up to the ceiling in her basement – dampness came through the floorboards upstairs. And a third one had a tornado (that accompanied Katrina) rip the roof off allowing for it to rain inside.