@xavimao
re: OXYGEN
Of course you can use pure oxygen to breathe on no-pressure(as in vacuum) or low pressure environment.
But there is a threat to that.
God did not give us pure oxygen to breathe right?
Instead He gave us a lesser content of oxygen (21 percent in the air) [And Yes there is a God!]
There's a reason for that. Aside from reducing unnecessary fires or combustion--
After 24 hours of breathing pure oxygen (24 hrs is the maximum safe period of use)
Pure oxygen damages the lungs and some say even the brain.
Harper's team used functional magnetic resonance imaging (fMRI) to get detailed pictures of what happens inside the human brain during two different breathing cases. Increased blood flow determined by the turn on of different brain areas makes them glow on the image.
14 healthy children, aged 8 - 15, had to inhale 100 % oxygen, while their breathing and heart rates were recorded. After 8 minutes, when the children' respiration returned to normal, the team had them breathe a gas mix made of 5 % carbon dioxide and 95 % oxygen.
Scans in the two situations were analyzed. "When the children inhaled pure oxygen, their breathing quickened, resulting in the rapid exhalation of carbon dioxide from their bodies. The drop in carbon dioxide narrowed their blood vessels, preventing oxygen from reaching tissue in the brain and heart", said coauthor Paul Macey, associate researcher in neurobiology.