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Flying underground

Human powered flight by means of subterranian hyper-baric chamber.
  [vote for,

I've heard it said that if the moon had a earth-dense atmosphere human powered flight would be possible. The moon has 1/6 of earth's gravity and a person weighs just 10-15kgs (22-33 lbs).

Since the moon isn't going to have an atmosphere any time soon... why not think about it the other way around and increase air density?

If you had a pressurised chamber with 6 or more times the density of air at sea level it could be possible for a human to fly in an apropriate birdsuit or pedal powered aircraft. If I am correct, the denser air would allow a much better lift/drag ratio in the range of what would be necessary for human powered flight.

Presently human powered aircraft on earth can only fly for a few minutes pedaled by a super fit olympic cyclist. The huge wings and rotors needed generate alot of drag and are very inefficient at converting human-power into lift.

Building such a chamber is going to be rather expensive. However, a large underground cavern could be pressurised as the weight of the surrounding rock would more than offset the pressure. Paint the ceiling blue with fluffy clouds and people would pay for the thrill of their lives.

Pressure could even be used hold up a 4 foot thick ceiling of dirt and/or concrete across a huge interior space - as big as you like.

Before anyone comments about pressure, deep sea divers can withstand up to 16 atmospheres before pressure starts effecting the brain and internal organs - so 6-10 bars would be not be unrealistic.

So, thoughts people?

venomx, Jul 28 2003

Gossamer Albatross http://www.museumof...tdisplay.html?ID=20
"On June 12, 1979, the Albatross, powered and guided by pilot Bryan Allen, made an historic flight across the English Channel. The record-breaking flight covered a distance of 22.25 statute miles (35.6 km) in two hours and 49 minutes." [phoenix, Oct 17 2004]


       Would the denser air (and therefore higher oxygen levels) confer extra stamina upon the flier?
friendlyfire, Jul 28 2003

       "Presently human powered aircraft on earth can only fly for a few minutes pedaled by a super fit olympic cyclist."
If you consider three hours just a few minutes. I'll point out that this is 1970's technology.

       Beyond that, you'll need a serious business model. This ain't Disneyland, Chester. Not just anyone will be able to ride. It will also make an appealing terrorist target.
phoenix, Jul 28 2003

       Only 6 times the density of air? Why wuss out? Crank up the pressure and people will float like corks. Plus then you could enjoy and not have to be in great shape.   

       Actually, as I think about it, aren't there undersea laboratories full of helium/oxygen at pressures of 6 atmospheres and above? I wonder if the researchers down there felt more buoyant? Hmmm.
bungston, Jul 28 2003

       Pressurize an aqueduct. - The infrastructure is already there.   

       //deep sea divers can withstand up to 16 atmospheres// - wussies - all of ‘em.
Shz, Jul 28 2003

       I'm definetly not an expert here, but wouldn't a hyperbaric chamber of that size be a little hard to pull off. If it leaked, what would happen? Wouldn't it explode, to the general dismay of the hapless inhabitants above? You could build it under the sea floor, in which case no one would complain except for a lot of fish and some scientists floating about in their own underwater chambers.
zindog1282, Aug 08 2003

       I believe there are salt formations in the USA that could be hollowed out to make a cavity big enough to try this in. I seems to have heard somewhere that such cavities are used to store crude oil.
Mogo, Aug 22 2003

       Sounds like great fun, if you can make it happen! The acoustics would be odd and dreamlike too. With lights out, could make for the ultimate sensory deprivation (or indulgence...) chamber.
n-pearson, Aug 22 2003

       Why not strap on a scuba tank and try this right now in the ocean? Same effect really.
Madcat, Aug 22 2003

       Diving (and even snorkeling) are wonderfully flightlike, but I think being able to breathe freely while swimming in air would be better yet.
n-pearson, Aug 22 2003

       Actually the max pressure a human can stand without getting serious Nitrogen Narcosis is 6 bar= 50 m =165 feet under water. Any diver knows that this would require a LONG time to decompress from. Using helium would be counter productive because it's density is so low. BUT you could pressurise with air to 10 bar or more and have the aeronauts have a breathing set with heliox mix. Still huge decompression problems. This would be worse if you were unfit. Would probably be easier to have a steel vessel on the sea bed where the outside pressure is the same. If the hangar were pressurised with air and the aircraft had large (but not huge) spaces full of helium, this would add significant lift. The air would be so dense that it's not certain that the aeronaut would feel 'free as a bird'.
RusNash, May 01 2004

       + But it would be simpler to get rid of the nitrogen and replace it with sulfur hexafluoride. Then you'd only need a pressure of 1.5 bar, and no narcosis problem. Even with one bar, you might be able to fly, as the breathing mixture would be four times as heavy as ordinary air.
ldischler, May 01 2004

       This idea has been preheated....see John Varley's " Tango Charlie and Foxtrot Romeo " 1987.
normzone, May 01 2004


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