Mountain High

December 18, 2008

Have you ever been to a high altitude and found yourself gasping for breath? One listener asked why that happens.

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Transcript

BOB HIRSHON (host):
The air up there. I’m Bob Hirshon and this is Science Update.

Listener Sanjay of Mumbai, India asks: why there a scarcity of oxygen at the peak of mountains. We turned to physicist Stephen Merkowitz of NASA. He says it’s not just oxygen that’s rare up there – all of the gases that make up our atmosphere are scarcer. You see, down here at sea level, there’s lots of atmosphere above us, pushing down and making our air denser.

STEPHEN MERKOWITZ (NASA GSFC):
As you go higher and higher in altitude, as you climb a mountain, say, there’s less atmosphere above you, so there’s less air pushing down on you, which makes the air thinner.

HIRSHON:
And thinner air means less oxygen per breath than our bodies are used to. If you have a science question, call us at 1-800-WHY-ISIT. If we use it, you’ll win a Science Update mug. I’m Bob Hirshon for AAAS, the science society.