[image: Niobe&Enfants_1770painting_Anicet_Charles_Gabriel_Lemonnier.jpg]
*Niobe: *A portrait of imperishable grief
Do you remember Tantalus?   You know, the inexplicably wicked Lyrdian king
who stole the gods' nectar and then became the most loathsome of dinner
hosts by serving the gods his own son Pelops as the entree?   Zeus punished
this extreme etiquette breach by tossing Tantalus into Tartarus where he
languished for all eternity in a state of implacable thirst and insatiable
hunger.    Yes, that Tantalus.      He also had a daughter, Niobe, who,
happily, was not sauteed and served as her brother had been.     One might
claim, however, that her ultimate fate was scarcely less horrible.
Having been the daughter of Tantalus and Dione, whose name literally means
"goddess," Niobe naturally grew up to be a ravishingly beautiful young
woman.     Though pursued by many suitors, Niobe chose Amphion, a son of
Zeus, to be her husband.    Amphion was a world renowned musician who once
helped his brother, Zethus, the Thebian king, build parts of the city
literally with his music.   The stones were said to have moved of their own
accord in response to his lyre melodies, much to the disgust of his ultra
masculine brother who had to move the stones manually.
Soon after her father was killed and condemned to Tartarus, Niobe and her
new husband ruled Lydia together.    (Her brother Pelops, whom Zeus
resurrected after Tantalus made a meal of him, had already left Lydia and
conquered the region that was thereafter known as the Peloponnese.)     One
could describe their union as bountiful. They sired seven boys and seven
girls, all of whom were as flawlessly beautiful as their mother.    For
many years Niobe and Amphion ruled Lydia, and then Thebes, wisely and
justly.  Under their dominion both kingdoms prospered.    The king and
queen reveled in their abundant wealth, the love of their many children,
and the adulation of their subjects.   Paradoxically, these blessings
brought forth in Niobe the mad arrogance that had proven to be her father's
undoing.       During the 30th year of her reign Niobe was presiding over
the annual festival celebrating Leto, the mother of Apollo and Artemis.
 Having observed the throngs of admirers gathered before her, Niobe
dispensed with the usual formalities and spoke out boldly,  "Why do we
bother to revere and celebrate Leto, the goddess whom none here have ever
beheld?   I stand before you now as I have stood before you for thirty
years: as your queen and protector.    Burn the incense in my honor and
that of my beloved husband whose harmonies rival those of the muses,
themselves.    Sacrifice to me, the mother of fourteen and not to Leto, who
sired only two.     Pay homage to me, your beloved liege, and not to Leto
who was so reviled that only a floating island would give her refuge when
needed to give birth to her only two children."   Appalled by Niobe's
boldness and impertinence, Leto commanded Apollo and Artemis to punish the
queen severely.    They both flew from Olympus to Thebes and swiftly
slaughtered all fourteen of her children with arrows.    Niobe helplessly
watched as her seven sons and daughters fell dead before her.    Her grief
was said to have been boundless and for many days she wept inconsolably
while the corpses of her children remained above ground.  On the ninth day,
the gods, themselves, interred the bodies and Niobe remained rooted to the
spot where she beheld her children's deaths.   Eventually she was
transformed into a rock that was placed either under a snow shroud or next
to a waterfall so that it was always wet, as though moistened by an
unrelenting flow of tears.

THE SOUTHWORTH PLANETARIUM
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Julian Date: 2458983.16
2019-2020:  CXLVI

THE DAILY ASTRONOMER
Wednesday, May 13, 2020
Remote Planetarium 33:  The Sun's Structures

[image: video-Los-Angeles.jpg]

We would like to give you a homework assignment.    After you read today's
article please walk to Los Angeles.    We understand that the separation
distance might be considerable.   Any Portland (ME) resident, for instance,
can expect a 3080 mile journey, give or take a few steps.      You might be
closer or more distant.    How much time would walking such a distance
require?   Well, depending on how often you decide to stop to wonder if the
whole thing isn't just a little bit futile, the trip might require at least
a few months.    The good news is that this jaunt to LA is merely part one
of a two part exercise.   Once you reach Los Angeles, you must walk back to
your starting point.   During your return journey, however, you must stop
at every third house you encounter and enter it. (We'll give you a nifty
mechanism that will enable you to unlock any door with just a casual wand
wave.)   Once you enter the house, please sit cross legged on the floor and
don't leave until the homeowner chucks you out.    As soon as you're
ejected,  you must walk in the same direction toward which you were thrown
until reaching the third house.    You would continue to infiltrate homes
in various directions until you eventually reach your home city.      How
long would this trip require?    Well, yes, just about forever.      Good
luck.

What is the point of this exercise? Simply to enable one to appreciate the
arduous journey the solar photons experienced before they scorched the
beach sand or streamed through your window.

[image: Random-Walk.jpg]
The Sun generates energy in its core, where thermonuclear fusion reactions
convert hydrogen into helium.   These reactions also transmute from the
matter into energy.  The released energy "migrates" out of the core
extremely slowly as each photon is absorbed and re emitted millions of
times by intervening atoms .  The emissions can send the photon in any
direction.
We'll follow this photon during its journey:

*CORE*
Welcome to the Sun's hottest, densest and most active region.    Here one
would experience temperatures exceeding 27 million degrees Fahrenheit and
densities 150 times greater than water.     This is the only region in
which thermonuclear reactions occur.  Every second the Sun "burns" 647
million tons of hydrogen to produce 643 million tons of helium.  The
remaining material is converted directly into energy.   Astronomers
estimate that the Sun has enough hydrogen reserves to sustain the
hydrogen-to-helium reactions for the next five billion years.  Although the
core's boundary is 0.2 solar radii from the center, the core's volume is
only 0.8% that of the entire Sun.

*RADIATIVE ZONE*
Here is where the arduous solar photon migration truly begins.    The gamma
radiation streaming out from the core is absorbed and re-emitted over the
course of nearly 300,000 years.   Consequently, the radiation that leaves
the radiative zone runs the gamut of the entire electromagnetic spectrum.
  We can count ourselves as fortunate as we certainly wouldn't be here if
the Sun cast only gamma radiation into outer space.

*CONVECTIVE ZONE*
What is the difference between the radiative and convective zones?   Well,
convection, actually.

[image: sunsect.jpg]

The gases within the convective zone travel through convective cells that
deliver heated material from the region just above the radiative zone to
the upper areas where the material cools. The cooled gases, being more
dense than its surroundings, descends back toward the radiative zone where
it is reheated and then ascends again toward the upper regions.

Above the convective zone is the sun's upper regions, a highly complex area
we will explore tomorrow as we conclude our tour of the Sun.





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