Disney-comics digest #652.

[Elmo]

donrosa at iglou.com (Don Rosa) writes:
>        Perhaps you didn't realize that my shaft was not FULL of air. That
>was the very problem I was trying to deal with -- I needed the characters to
>be able to talk and breathe at the bottom, yet not be squished into jelly by
>the titanic pressure of 4000 miles of air.

Water's darn near incompressible, and the human body is water to first
order.  4000 miles of air--about, roughly, 1000 atmospheres if my math 
is OK [1]--shouldn't cause too many problems as long as you're reasonably 
slow going down and *very* slow coming up.  Airtight containers will have
a lot of problems, natch.

Do ducks have Eustachian tubes in their ears?

	greg

[1] Water is roughly 1500 times more dense than air (22.7 liters of
air weighs about 15 grams; 22.7 liters of water weighs about 22.7 kilos) 
and you gain an atmosphere every 33 feet under water, so you gain an atmosphere
every 20000 feet, or 4 miles, of air.

Note that I'm ignoring the compressibility of air, which will increase
the pressure as you go lower, but not more than about a factor of two
in 4 miles.  (At four miles in altitude, ignoring compressibility,
we would expect pressure to drop to zero, given 1 atmosphere at sea level,
but because the air gets thinner, it goes higher, so there's actually
about 1/3rd atmosphere at 4 miles up.)
--
"Cabbage:  A vegetable about as large and wise as a man's head."
--Ambrose Bierce
  
elmo (morrow at physics.rice.edu,morrow at fnalv.fnal.gov)