"Wolfgang" wrote in news:5s5gs2F153pe0U1
@mid.individual.net:


"Tom Nakashima" wrote in message
...

Man doesn't lose equilibrium in water.

Not true.

Wolfgang



Correct. The semicircular canals have no problem, but the otolith organs
get confused because there is a bouyancy in addition to gravity. How
this manifests is interesting, but the bottom line is that a diver can
become very disoriented in water, enough that the most reliable way of
telling "which way is up" is to follow your air bubbles.

It's much like microgravity during space travel. Oddly, divers don't get
microgravity sickness like 50% of the astronauts, but that might have
something to do with the lenght of exposure.

One of the things that really gets astronauts hurling is odd visual cues.
Some of the compartments on the space station and shuttle, for example,
have different "up" directions, simply because thats how the things were
built. Walking (or floating) from a room with one orientation to the
next with different orientation could very well be the trigger for the
ride on the porcelain bus.

Underwater, though, I suppose visual cues can be very limited, and this
might contribute to disorientation.

I don't know why fish go into some sort of paralytic state when held
upside down, but it might be vestibular. Would be very interesting to
find out, anyway.

--
Scott
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