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Re: Odyssey Orbit



Bernard Cleyet wrote:
my latin teacher (ca. 1952) said a gnomonic device was an
aid to memory. It's a stretch to go from the sundial that
knows the time?

OK, I can see where you're coming from with that, something that points
(a gnomon) you to something else. Cool! You know, that may have been
an original creation by your teacher; if we popularize it, your teacher
might become an etymological source. I've always used the more
conventional term "mnemonic".

Actually I couldn't find any etymological reference to peri meaning nearest
-- mostly about as in periphery -- about is rather nearer than farther?

I think orbital mechanics is the only field which uses "peri" to mean
"near or nearest" as in periapsis, perihelion, perigee, perijove and
perilune. I don't know the etymology of that, either. It surprises me
that nobody has popularized a Mars-specific terminology for periapsis
and apsoapsis like that used for the Moon and Jupiter. Have the orbit
geeks tired of the name game?

Other than that, "peri" has two usages, the second a technical
topic-specific variation of the first:
(1) "all around" as in periscope, peripheral, perimeter, and
peripatetic;
(2) the "surrounding or enclosing tissue" biological variation
as in pericardium, peritoneum, periostium and periodontal.

Thanks and best wishes,

Larry

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Larry Cartwright <exit60@cablespeed.com>
Retired (June 2001) Physics Teacher
Charlotte MI 48813 USA
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