RE: ATM Sea Scope

[Anthony Stillman <atmer@flash.net>]

In response to both on and off list questions.

The Humu-humu-nuku-nuku-apuaa is the state fish of Hawaii.  Incidentally,
its pronounced   who moo - who moo - noo koo - noo koo - ah poo ah ah

I hadn't thought about tube currents or for that matter whether
equalization would be best accomplished by sucking or blowing. ;-)

The telescope works below the surface.  I suspect its crush depth is
determined by the ABS, which is slightly buoyant.  However, I also suspect
exposure to extreme pressure would only thin the walls of the ABS tubing,
not destroy it.

The Galilean design has significant eye relief.  The telescope can be used
several inches from the observer's eye, with or without an intervening air
space (mask).

I dismissed using a air space design for two reasons.  I wanted the
instrument to either have zero buoyancy or sink.  My intent being that it
be usable while, and not interfere when, diving.  If you have ever tried to
dive with one of those underwater cameras a.k.a. air bubbles in your hand
you know what an inconvenience it is.  I considered counter weighting an
air spaced instrument, but seals have a tendency to leak and besides, it
didn't seem as cool.

>From my copy of the CRC Handbook of Chemistry and Physics at 589.3nm and 20C
sea water from the Gulf of Mexico    nD = 1.3348
pure water                           nD = 1.33335

I wasn't joking about the afocal mangin cassegrain.

All three morays I encountered were fairly close to shore in fifteen to
twenty feet of water.  Two were young, being only four to five feet in
length.  Both of these were light brown with white spots.  The third was
older, seven or eight feet long and dark brown with white spots.  Actually
there is thin black ring around each white spot.  All three had nasty sharp
pointy teeth.


Anthony