Tuesday, August 19, 2014

Oxygen concentrations

This is something I have been meaning to mention for a while but don't think I have done... been sitting on it as part of the idea for an SF storyline, but fuck it - I have more of those than I could use in a lifetime of writing, ideas are not my problem.

Something we take for granted is combustion - simply apply heat to a wide variety of things like wood or coal or oil and they'll happily burn. But do you realise that if the concentration of oxygen in the atmosphere was only slightly lower this would not be true? It's far more critical than you might think, a reduction of only a couple of percent is enough to stop combustion... But life would still be perfectly possible, humans can survive perfectly happily at oxygen concentrations far below those necessary to support combustion.

So what? I hear you think... well, the thing is that the oxygen concentration in our atmosphere has varied quite widely and could very easily have been lower than it is for the whole of human existence - now, if that had been the case then fire would not work... without fire we could not have developed any form of technology... no extracting metals from ores, no alchemy leading to chemistry, no glass, no ceramics, no steam power...

What a terrible trap lurks for intelligent beings who happen to evolve on a planet with such an atmosphere.