What is the lowest PSI level a Human being has ever been subjected too? I know Mt. Everest those guys go down to like 7 psi or so. I figure there has to be some Military or NASA tests on this or on lab rats.
How Low can U GO ?
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Vacuum tests are pretty gruesome. I don't know if the data gathered by the SS physicians are still available but they dropped human subjects to near zero.
If the gradient is not too steep, the subject would just become unconscious. I think this has occurred with decompression in aircraft. Not sure what altitude but 40,000 feet should do it. The equivalent pressure would be about 2-3 psi. I believe 7 psi is equivalent to an altitude of 25,000 feet, not sure of the exact number but this approximate elevation is the accepted limit of human adaptability.
If the gradient is not too steep, the subject would just become unconscious. I think this has occurred with decompression in aircraft. Not sure what altitude but 40,000 feet should do it. The equivalent pressure would be about 2-3 psi. I believe 7 psi is equivalent to an altitude of 25,000 feet, not sure of the exact number but this approximate elevation is the accepted limit of human adaptability.
OP
I'm going to do some research and try to figure it out. When you say almost zero do you mean like 1 psi or even lower?
A little refinement to BMS's post. Given time to adjust how low of an air pressure can humans survive.
I am sure that us humans can go pretty low....provided that we had O2 available, i can't see why we couldn't go to less than 1 psi, but not zero. we would suffacate at zero even if we physically can take it....
disclaimer: this is just my 2 cents (spoken opinion) and is not backed up with any proof. Please don't flame
disclaimer: this is just my 2 cents (spoken opinion) and is not backed up with any proof. Please don't flame
OP
If we had something to breathe from do you think the body could take 0 psi if pressure was released at an extremely slow slow slow rate?
I hope that this speculation is related to diving. At 0.0 psi, the blood would boil. As I said before, humans cannot adapt to breathing air at altitudes above 25000 feet(about 7psi), that is the limit for functioning at a normal level. It is possible for adapted or non adapted humans to go higher while breathing O2, but not to 0 psi.
Are you trying to experiment with travel gas or what? I think that the recommended limit for divers is 16% O2. If so, multiply this by 14.7 and we get an O2 partial pressure of 2.3 psi. This would be the ambient atmospheric pressure boundary with respect to limits of oxygen uptake and life support. It is equivalent to about 10,000 feet on air and 40,000 feet breathing O2. However, it appears that altitude adapted humans can survive and function at 1.5 psi PP O2, which might mean that they can survive while breathing O2 at 50,000 feet or higher. I don't know if physiological factors, other than oxygen utilization, would prevent this though. It sounds dangerous to me.
Are you trying to experiment with travel gas or what? I think that the recommended limit for divers is 16% O2. If so, multiply this by 14.7 and we get an O2 partial pressure of 2.3 psi. This would be the ambient atmospheric pressure boundary with respect to limits of oxygen uptake and life support. It is equivalent to about 10,000 feet on air and 40,000 feet breathing O2. However, it appears that altitude adapted humans can survive and function at 1.5 psi PP O2, which might mean that they can survive while breathing O2 at 50,000 feet or higher. I don't know if physiological factors, other than oxygen utilization, would prevent this though. It sounds dangerous to me.
You can't get too close to zero- Your blood will boil, even if you have enough oxigen. If you do it with 100% oxigen, it might be enough to sustain llife, but like I said- there are other problems.
Bingo!
About 55,000 feet is as high as you can go without your blood boiling. At that altitude you have to pressure breathe oxygen to overcome the partial pressure of CO2 in the lungs and get some O2 to your blood. We normally breathed pure oxygen at all times in tactical jets at a positive pressure of 2 inches of water over ambient. Our regulators automatically increased this positive pressure at cabin altitudes over about 25,000... any flights above 50,000 required a full space suit to prevent instant death in the event of cabin depressurization.
One of the primary differences in our (US) spacecraft and the Russians, and a major point in engineering joint ventures, is that we use pure oxygen at about 5 psi in our ships while they use air at 1 standard ATM.
Rick
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