Re: Mt.Wilson

Mike Simmons wrote:
> A lot less oxygen. The decrease in atmospheric pressure is approximately
> exponential so the higher you go the more of a difference each incremental
> increase makes.

This is the part that isn't right. The higher you go, the less of a
difference each incremental increase makes. That's the nature of a
negative exponential. So the difference between 0 and 4,000 feet is
larger than the difference between 4,000 and 8,000, which in turn is
larger than the difference between 8,000 and 12,000. This is opposite
to what you wrote. (Or, at least, it seemed opposite to what you
wrote.)

> Rather than physics, you're referring to physiology and what you say isn't
> right. We don't have a "surplus of oxygen" to use.

No. That's not what I meant. (I must have confused you.) What I mean
is that wherever we live (within reason), we can make do with less oxygen
than there actually is in the air around us--the reason being that if we
needed exactly that much oxygen just to go about our usual business, we
wouldn't be able to exert ourselves any further. That's all I meant by
surplus. I certainly didn't mean that we have a backup supply of oxygen
lying around to use.

The implication is that we can go about our usual business at a higher
altitude without noticing anything terribly untoward, but the moment we
try to exert ourselves, we experience shortness of breath. (As you note,
this isn't directly due to a shortfall in oxygen, but to a overrun of
carbon dioxide. I seem to recall an experiment in which the subject
breathed more or less pure nitrogen. He didn't notice anything terribly
wrong until just before he passed out. He was quickly revived, though.)

--
Brian Tung <brian@xxxxxxx>
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