Hello, and welcome to another episode of No Such Thing as a Fish,
a weekly podcast coming to you from the QI offices in Covert Garden.
My name is Dan Shriver, I'm sitting here with James Harkin, Andy Murray, and Anna Chazinski,
and once again we have gathered around the microphones with our four favorite facts from the last seven days,
and in no particular order, here we go.
Starting with you, Andy Murray.
My fact is that when you are 30 meters underwater, your lungs are only a quarter of their normal size.
That is incredible.
Yeah.
How?
What's, because there's not enough air in them?
Well, there's the same number of air molecules if you just take one lungful and then you dive down,
but the water pressure on them is much higher, meaning that your lungs shrink.
So if you're at sea level, all the air above you,
if you imagine a column of air stretching all the way up to the edge of the atmosphere,
one square inch of that column would weigh 14.7 pounds, right?
Mm-hmm.
So we say the pressure, the air pressure at sea level is 14 pounds per square inch, 14.7.
It is amazing actually to think all of that air pushing down on you whenever you're walking down the street.
Yeah.