THE SOUTHWORTH PLANETARIUM
207-780-4249   www.usm.maine.edu/planet
<http://www.google.com/url?q=http%3A%2F%2Fwww.usm.maine.edu%2Fplanet&sa=D&sntz=1&usg=AFQjCNHulkHuLP13bOG2PkNrPazsGWFs2A>
70 Falmouth Street   Portland, Maine 04103
43.6667° N                   70.2667° W
Altitude:  10 feet below sea level
Founded January 1970
Julian Date: 245906.16
2019-2020:  CV
            "As we were saying..."


THE DAILY ASTRONOMER
Wednesday, February 26, 2020
Exit Sign Astronomy


And then we saw the Exit signs.
You know those signs:   ubiquitous, yet unobtrusive.  They are the Banquo's
ghost of the modern age: lurking in the corners and corridors of buildings
across the world.    Guiding us all without imposing their presence on us.
We pay them little mind unless poison gas, mephitic fumes or some other
menace insinuates itself onto our personal space.  Then we look for them as
a desperate wretch seeks out a sagacious guru.

Our subterranean star dome theater contains two such signs, one for each
exit, as one would expect.   Be it in the middle of the day amidst the
teeming throng of patrons or in the deep of night accompanied only by the
unearthly entities that populate dark empty spaces, the two red exit signs
have stood as sentinels in their place since the planetarium hatched out of
the seafoam of Paphos.   Like red dwarf stars with life spans exceeding a
trillion years, theirs is a perpetual light destined to remain luminous
even when the rest of society perishes in a sudden conflagration (November
3, 2020.  Don't forget to vote.)

And then we saw the Exit signs.
Green.   Beautifully bright,  drop dead gorgeous vibrant green reminiscent
of dew-moistened shamrocks and a youth overflowing with promise.  WHAT?!
The exit signs were changed, in accordance to the rules inscribed on the
most recent slab of blue sapphire to have descended out of the highest
cumulonimbus.  Granted, the other signs were a bit worse for wear after
having exuded their feeble light for the better part of a half century.
In fact, the "t" in the one marking the south door was almost wholly
obscured and since none of us could figure out what EXI next to a door
could possibly have meant, it is fortunate that the change occurred.

And then we saw the star field.

Las Vegas

[image: what-happens-in-vegas.jpg]

Oh, crumb.
While those beguilingly pretty exit lights imparted a pleasingly numinous
glow onto the star dome, the stars themselves were difficult to observe.
And, well, yes, that does sort of defeat the purpose of a planetarium,
doesn't it?

Hmmm...

Well, we can certainly explain the problem.   The problem is with the
color.    The previous exit sign glowed red which, while admittedly
unimpressive, is still wonderfully monochromatic.  In those observatories
where people still actually look through telescopes red light illuminates
the interior.   Such light allows observers to scrutinize star charts
without impairing their dark adaptation.     People who venture outside to
see the night sky will often take a red flashlight to illuminate their own
charts for precisely the same reason.       If you take out a green light,
you might as well not even bother.

Green is the astronomer's enemy, hence the status of their bank accounts.
All the same, we loved the green light from the first moment! Not only was
it pleasing to the eye, it engendered a sense of exuberant joy and
imperturbable serenity in us...well, when we weren't cursing about it.
 Realize that we are all descended from countless generations of adamant
sun worshippers.  Our ancestors revelled in the searing sunlight that
scorched the savannah and filtered through forest canopies. We still yearn
to be near such light, despite the unalloyed bliss we all experience having
evolved to the point where we're now cloistered in cubicles under pervasive
fluorescent lights.




[image: index.jpg]
 The Sun's maximum light output is in the green part of the spectrum:
between 483 - 520 nanometers.   A light that was similar to the emerald
glow that washed tsunami-like over every nook, cranny and crevice in our
underground Universe.  The Sun was in the planetarium!

No wonder we were all so damn happy.

Fortunately, we explained our predicament to the two ingratiatingly
pleasant associates who installed the exit signs.   They managed to
persuade the powers that be to allow us to have red exit signs again,
albeit brighter ones that illuminate all the letters.     I am admiring
them right now: the signs, not the associates, that is.   Both brighter
red, but not blindingly so.  The dancing, bubbly extroverted cousins to the
timid, unassuming red exit signs that chewed their fingernails and read
stoic philosophy for pleasure.

The starfield is restored.
The exits are well marked.
The planetarium can now persist after having survived its latest
existential crisis.     Despite these tribulations, we'll miss the green
light.  In fact, we'll always remember that week in which the green exit
signs cast their verdant luster into our underground chamber.      We know
that those green exit sign days will always remain phantom like in the
space-time matrix, metaphysically extant but irretrievable, thank heavens.

Also, it demonstrates that in a world that allows for all possibilities and
in which all things can contribute a verse in this powerful play,  every so
often even something as peripheral as an exit sign can suddenly find itself
in the focal point of our attention.  Perhaps another fifty years will
elapse before we put the exit signs in the spotlight again.  One can only
hope.

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