Re: Royal Institution lecture
IIRC they sometimes use a lower O2 concentration on submaries, for that reason. And if http://bowlofstew.com/everest-oxygen-concentration and my memory is correct halving the O2 content would "just" but you a bit over the Mt Everst Base camp (around 6000 m). Perfectly survivable for most people, at least short term.
Biting the hand that feeds IT
