[image: Cetp.jpg]
*Cetus:*   *The First Leviathan*
Remember the maxim, "In the Greek mythological realm, the people conquered
the land; revered the mountains and feared the sea."   After all, the land
always yielded to storming armies of well equipped, thoroughly trained and
sufficiently fed soldiers.  The towering, cloud-puncturing summits seemed
suitable abodes for the lofty deities. Yet, the opacity of the wine-dark
sea proved most foreboding: Ships merely traversed the sea's surface and
even the most intrepid divers could plunge little more than a hundred feet
below it.   The lower depths, having been both invisible and impassable,
were unknown and, as such, engendered morbid fear. The most fearsome
creatures lurked in the briny deep. Cetus, sometimes called the "whale" or
"sea monster." was arguably its most dreaded denizen.

Cetus first appeared around during the reigns of Cepheus and Cassiopeia,
the king and queen, respectively, of ancient Ethiopia.  Cassiopeia, an
admittedly beautiful woman, was also known to have been shamelessly
boastful both about her own prepossessing appearance and that of her only
daughter Andromeda.   She made the grave error of declaring that
Andromeda's beauty surpassed that of the Nereids, ocean nymphs beloved of
Poseidon, the god of the ocean.    Poseidon was so incensed at this
impudent boast that he unleashed Cetus from its undersea lair to destroy
Cassiopeia's home village.  The sight of the ferocious monster rising from
the waves induced Cassiopeia and her husband Cepheus to consult their local
sage for advice. He told them of Poseidon's displeasure and instructed them
to chain Andromeda to the rocks as an offering  to Cetus.  They miserably
agreed and agreed to sacrifice their daughter.  Fortunately, Perseus, the
warrior who had just recently slain the mortal gorgon Medusa, was flying
nearby on Hermes winged sandals.  He spied Andromeda and promptly
approached her parents with an offer to save their daughter in exchange for
her hand in marriage.   They readily agreed, of course, as they preferred
to suffer the indignity of having a brash son-in-law over the anguish of
watching their only child being devoured.     In some versions, Perseus
merely flew up to Cetus and showed her Medusa's severed head, a gruesome
trophy he had been carrying in his satchel. The sight of Medusa's face
petrified Cetus at once and Andromeda was saved.     In another, messier
version,Perseus flies around Cetus like a gnat and methodically dices him
into fragments with his sword.    In both versions, Perseus prevails.

Curiously, Cetus arose again, during the time of Heracles, Perseus's
great-grandson, and half brother.*    Trojan king Laomedon incurred the
wrath of both Apollo and Poseidon after he refused to pay the wage he
promised the two gods in exchange for their construction of the impregnable
walls surrounding Troy.   While Apollo smited Troy with a plague, Poseidon
deployed Cetus to ravage Troy.  Laomedon consulted an oracle which
commanded him to offer his daughter Hesione to Cetus, just as Cassiopeia
and Cepheus had offered their daughter Andromeda years before.     That
Cetus arose again isn't truly perplexing.  We remember that Poseidon
fashioned Pegasus out of Medusa's blood mixed with sea foam.
Reconstituting Cetus would have been well within his powers.  (The notion
that another poet simply re-used Cetus as the villian in another tale is
far too outlandish for us.)     On this occasion, Heracles and his cohorts
Telemon and Oicles had just returned from their battle against the Amazons
when Hesione was chained naked to the rocks.  Heracles approached Laomedon
and promised to save his daughter provided that the king give him the
splendid horses that Zeus had given him to compensate him for the abduction
of Ganymede.   (Years earlier, Zeus had abducted Ganymede,
Laomedon's eldest son, to be his cupbearer.)  Laomedon also quickly agreed
to Heracles' terms.   Having not been in possession of a severed gorgon
head, Heracles had to fight the monster head on, which he did with his
characteristic vigor.   Having seen that Cetus was not only enormous, but
completely protected by rock-hard scales, Heracles promptly jumped into its
mouth and dove down its throat.  He then spent three entire days hacking
relentlessly at his innards with his broad sword.   He deftly avoided being
swept along the alimentary canal and ultimately managed to slay Cetus
literally from the inside out.   Heracles emerged from the cadaver and
demanded payment, which the crook Laomedon refused to tender.    The Trojan
king had qualms about paying his debts.

Cetus made no other appearance. Presumably, his second death was his last
and Poseidon was content to allow its body to dissolve into the same
wine-dark sea from which it had twice arisen.    Although other creatures
loitered about the oceans, none of them ever seemed as formidable as Cetus,
the twice-slain sea monster


*Zeus fathered both Perseus and Heracles.  Heracles' mother Alceme, was the
daughter of Electyron, one of the daughters of Perseus and Andromeda.
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:  2459280.18
2020-2021:  XCIX

THE DAILY ASTRONOMER
Tuesday, March 9, 2021
Exploratorium XXIX:  Night and Day

*"What is the most extraordinary astronomical phenomena of them all, in
your opinion?"*

Many people have posed that question to me and my response has proven
profoundly disappointing.  One would think I would cite time-warping black
holes, or, perhaps, the Big Bang inception event.   Actually,  I think the
most extraordinary is the periodic transitions from day to night and then
back again.  If you find that assertion somewhat disappointing, as well,
please bear with me, at least for a bit.

                     [image:
https___blogs-images.forbes.com_startswithabang_files_2017_09_1-6ki7918Px2N2LJW8JdAzEg.jpg]

*The Stellar Furnace*
Daylight occurs when our part of this highly massive planet, which is
rotating in a void, turns toward the Sun, our parent star.  Like all active
stars, the Sun generates prodigious amounts of energy in its core, where
unrelenting thermonuclear fusion processes convert lighter elements into
heavier elements. During that process, some of the initial material is
transmuted into energy.   Such reactions have been occurring in the Sun for
billions of years. The empyreal sphere that casts blinding light onto our
backyard and bedrooms once shone brilliantly over Triassic skies, above
newly crafted pyramids and will someday loom high over the topless towers
of 35th century city scapes.

*The Arduous Trek*
Blink!
Thank you.
During that moment when you blinked, approximately 646 million tons of
hydrogen was converted into helium within the Sun's core.   A minute amount
of that hydrogen became energy, generally in the form of gamma radiation.
  So, when will we feel that energy?>  Well, WE won't feel it at all.
The energy will slowly migrate out of the core and into the photosphere
where it will finally be released into space.    During the intervening
period, the photons created just a moment ago will undergo innumerable
absorptions and re-emissions.   Each emission will send the photon in any
number of directions.   (Analogously, think of how long a trip from New
York City to Los Angeles would require if one had to stop at every third
house and then were pushed out in any direction and had to walk in that
other direction until reaching the third house and beginning the process
anew.)   The sunlight generated when you blinked earlier will be emitted
into outer space in about 300,000 years!

Is the Sun visible to you right now? Look at any surface it illuminates.
You are seeing photons that the Sun generated around the time our species
first appeared.

*Earth's Allotment*

                [image: Roll_In_1_WhatIsTSIS-1.00001_print.jpg]

Remember that the Sun is nearly 100 million miles from Earth.    The Sun
radiates energy in every single direction.  Imagine the sun's light as a
rapidly expanding sphere moving outward.  Our planet receives about a
billionth of that energy,    Although the other planets and other solar
system bodies absorb small amounts, as well, most of it escapes into outer
space and becomes incorporated into the collective light of the Milky Way
Galaxy.     Not only are we bathed in ancient starlight on every sunny
day,  We are also receiving a negligibly small portion of the sun's
energy.     To give one an idea of the size of one billionth of something,
realize that one billion seconds approximately equals 32 years!

*Turning Earth*
The planet has been rotating since its formation nearly 4.5 billion years
ago. Of course, so, too, has the solar system,   When the primordial
material collapsed to form the Sun and its retinue of attendant bodies,
everything started to spin.   Earth is moving around the Sun's gravity well
and it also turns on its axis.     Although Earth has been turning
constantly since its birth, its rotation rate hasn't remained constant.
Earth spun much faster a few billion years ago, just as it will rotate much
more slowly a few billion years from now.    The moon is responsible for
this changeable rotation rate.  Or, more precisely, the moon's recession is
responsible. As the moon slowly moves away from Earth, the planet's day
length decreases, on the order of milliseconds per century.

Day occurs when an entire world spinning in space turns toward a star that
casts a minute amount of ancient light on us: light that started in the
roiling nuclear core.     At night, we turn toward the eternal darkness of
outer space and see the array of distant suns adoring our sky.      We've
scheduled our lives around these periodic transitions and so they might
seem mundane.    They're nothing of the sort...then again, nothing in the
Universe is ordinary.


To subscribe or unsubscribe from the Daily Astronomer:
https://lists.maine.edu/cgi-bin/wa?SUBED1=DAILY-ASTRONOMER&A=
<https://lists.maine.edu/cgi-bin/wa?SUBED1=DAILY-ASTRONOMER&A=1>