[image: Nauplius-.jpg]
*Clytemnestra: * A mother's revenge
Queen Leda, wife of King Tyndareus, hatched out the most remarkable set of
quadruplets the world had ever seen.   It is little wonder that she would
have done so, as their conception was, itself,  extraordinary.   Within the
span of a single night, Leda lay with her devoted husband and then also
with Zeus who seduced her while assuming the form of a beautiful white
swan.    Despite her mammalian ancestry, Leda produced two pearl white
eggs, one for each coupling.   From the egg she conceived with Zeus emerged
the girl who would become Helen of Troy and Polydeuces, also known as
Pollux.    Emerging from the other egg- the one that Tyndareus fertilized-
was Castor and his twin sister Clytemnestra.  Three of these children are
quite well known.  Helen's abduction precipitated the Trojan War.   Castor
and Polydeuces would go on to become the Dioscuri, immortalized in the
night sky as the "Gemini Twins."  Clytemnestra, the fourth quadruplet,
never achieved the same fame her siblings enjoyed.   Her relative obscurity
is rather surprising for hers was a deeply tragic, and therefore quite
compelling, story.
When King Tyndareus selected Menelaus to wed his stepdaughter Helen, he
chose Menelaus' brother Agamemnon to marry Clytemnestra.   Although the
arrangement was not of her choosing, Clytemnestra's marriage was initially
quite happy.  She and Agamemnon sired three daughters:  Iphigenia, Electra
and Chrysothemis and one son Orestes.   When the Trojan prince Paris
abducted Helen, Agamemnon and many other men who had also once sought
Helen's hand in marriage were obligated to sail to Troy to regain her.
 The hundred-ship armada Agamemnon assembled at first could not depart due
to fierce contrary winds.     The gales persisted for so long Agamemnon
consulted the prophet Calchas for guidance.  Calchas informed him that the
moon goddess Artemis had conjured the tempests in order to detain
Agamemnon's vessels. Just before Helen's abduction, Agamemnon had slain a
hare in a grove sacred to Artemis.  She summoned the winds as a
punishment.  Calchas regarded Agamemnon gravely. "Only by sacrificing your
eldest daughter will the goddess be appeased and winds abate."  Agamemnon
immediately sent a messenger back to his home to inform Iphigenia that she
was to be wedded to Achilles, Greece's bravest warrior, at once.    Knowing
that his daughter had long been smitten with Achilles, he expected her to
arrive quickly, which she did.   Without a word, Agamemnon unsheathed his
sword and ran her through.    The winds then ceased, permitting the ships
to depart.   Agamemnon was abjectly miserable, for not only did he just
slay his eldest daughter, but he did not know how he would be able to
explain what had transpired to his wife when he returned from Troy.  He
needn't have worried.    Clytemnestra had followed her daughter most of the
way down to the dock and then concealed herself so as to secretly witness
the marriage.       When she saw her husband slay Iphigenia, she fainted
with terror.     By the time she awoke, Agamemnon's armada had left.   From
that moment Clytemnestra's love for her husband died.
During the ten years that elapsed between Agamemnon's departure and his
triumphant return, Clytemnestra took her husband's estranged cousin,
Aegisthus, as a lover.   They conspired to avenge her daughter's death on
her father's return.  (It would have been pointless to have traveled to
Troy where Agamemnon was surrounded by protectors.)    When he did return,
he was in the company of his mistress Cassandra, the prophetess whose
warnings were destined to always go unheeded.     Flaunting his lover
before Clytemnestra merely added fresh insult to ancient injury.    To
Agamemnon's surprise, his wife welcomed him warmly and even behaved
graciously toward them both. "Dearest husband, I know what happened and
what act you were forced to commit by divine decree.   Be at peace, my
dear, for Iphigenia would want you to be.   You and your friend should
prepare for dinner.  Be hasty for all the children, save Iphigenia, are
hungry."
As Agamemnon was about to enter the bathing area,  Cassandra whispered to
him. "My love, I am terribly frightened.  Both of us will die before the
Sun sets."   He laughed softly and assured her that all was well.     "Be
content and quiet," he told her.  "I shall soon return from the bath I so
sorely need."        Only a few moments after Agamemnon submerged himself,
Clytemnestra and Aegisthus, who had been hiding in a nearby room, rushed
toward him.   While Clytemnestra ensnared him in his robe, Aegisthus pushed
him under water and stabbed him to death.   Having heard Agamemnon's cries,
Cassandra rushed to his aid.  Clytemnestra grabbed Aegisthus' short sword
and beheaded her.   (In some versions, they slayed Agamemnon and Cassandra
as they napped before dinner.)
Electra, the second child, heard what was happening and immediately
conducted Orestes out of the house.  "Mother has gone mad!" she exclaimed.
"She and Aegisthus have killed Father.   Go at once to Phocis to the home
of father's brother-in-law King Strophius.  Do not leave for anything until
you are old enough to help me avenge father's murder."     Eight years
passed until Orestes, then a grown man, resolved to rejoin his sister.
First, he consulted the Delphic Oracle, for he knew that shedding kindred
blood was the gravest of all mortal transgressions.  Apollo assured him
that he could avenge his father's murder without fear of retribution for he
would be protected by Hera, the powerful goddess of marriage.      Orestes
arrived at his home and found Electra out in the garden.     He brought two
daggers, one of which he gave to his sister.  They then ran into the house
and confronted Clytemnestra and Aegisthus.   Orestes engaged Aegisthus in
battle while Electra struck down her defenseless mother.   Electra then
assisted Orestes to disarm and then slay Aegisthus with multiple dagger
strikes.    Despite Apollo's assurances, Orestes and Electra were pursued
by Clytemnestra's furies, the ferocious female spirits that avenge the
slaughter of relations.      Orestes and Electra fled from their home with
the furies in inexorable pursuit.      The furies drove them both mad.  In
their delirious state, they almost slew one another before Apollo, himself,
intervened.   He thwarted the furies by agreeing to place Orestes and
Electra on trial for the double murder.  King Tyndareus was selected to
adjudicate the matter.     Though initially inclined to condemn both his
grandchildren for his daughter's murder, he was persuaded by Menelaus to
commute the sentence to a single year's banishment.  After this banishment
Orestes was betrothed to Hermione, the eldest daughter of Helen and
Menelaus.  About Electra little else is known.        Whereas modern
psychology recognizes the "Oedipus Complex" in males:  the latent desire to
kill the father and wed the mother, they have also identified the "Electra
Complex," a desire in girls to kill their mothers and wed their father.
However, one could argue that this condition is improperly named because
Electra never married her father.  With the aid of her brother, she merely
avenged his death.

THE SOUTHWORTH PLANETARIUM
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Julian Date: 2458980.16
2019-2020:  CXLIV

THE DAILY ASTRONOMER
Monday, May 11, 2020
Remote Planetarium 31: A Sun's Life - The Sun's Birth

Last week we learned how astronomers determined the sun's distance, size,
mass and chemical composition.      To humanity's collective astonishment,
they learned that our parent star is approximately 93 million miles away,
more than one million times larger and 330,000 times more massive than
Earth and consists primarily of hydrogen and helium.    Today, we learn the
details of the Sun's extraordinary birth approximately five billion years
ago.

The details begin with a structure similar to the one seen below:

[image: The_dark_nebula_LDN_483.jpg]
We're seeing the dark nebula LDN 483 located approximately 700 light years
from Earth within the constellation Serpens.  This irregularly shaped cloud
appears silhouette like against the stellar backdrop.    Likely numbering
in the millions, such dark nebulae are scattered throughout the Milky Way
Galaxy.  Approximately five billion years ago a dark nebula traveled
through the galactic star streams. This cold nebula was devoid of any
motion save for the weak eddies and currents that one tends to find within
such otherwise inert agglomerations of gas.

Then, within this primordial nebula's "vicinity," the following event
occurred:

[image: 5d6063e22e22af080b203e32.jpg]

We call this cataclysmic event a "Type II supernova."   Later on in this
course we will discuss these supernovae in greater detail.  For now,
suffice it to say that such supernovae occur when a highly massive star
explodes from the inside out.    This ancient supernova scattered heavy
elements radially throughout its intergalactic environment.   A small part
of that debris field plowed into the dark nebula, chemically enriching the
gases while precipitating a slow but inexorable collapse.    Were we to
witness the collapse, we would find ourselves becoming extremely bored.
 At first the nebula would exhibit only the subtlest shifting: like the
passage of distant shadows along a dark moor.   The heated supernova
remnants would glow, of course, until cooled through their dispersal.
Eventually, the nebula would develop "micro pools," regions within itself
that start to become measurably more dense than their surroundings.
Although we would still see little, the nebula will become more turbulent.
     The dense pockets gather more of the surrounding material making them
more massive and gravitationally attractive.    Akin to a snowball rolling
downhill that enlarges its surface area during its descent and therefore
constantly increases its capacity for accumulating more snow, the pockets
quickly gather an abundance of material.

While we wait for the gas gathering to continue, we need to introduce two
protons:

[image: BYpQBTI.png]
[image: BYpQBTI.png]
Please meet Heathcliff and Catherine: two simple positively charged
subatomic particles that just happen to be part of the bustling maelstrom
of hydrogen and helium atoms within one of these pockets. Yes, the one
destined to become our Sun.        These two protons are not particularly
remarkable.  For purposes of illustration we plucked them out of the gas
just for a moment.      Under ordinary circumstances they experience a
mutual repulsion as a consequence of their like charges.     Known as the
Coulomb barrier, this repellent tendency is a manifestation of
*electromagnetism*, one of the fundamental physical forces.      The
electromagnetic force causes like charges to repel and unlike charges to
attract.       You have perhaps noticed that if you bring magnets together,
they will snap together if the poles are different but will strongly resist
being brought together if their poles are the same.     These two protons
don't want to have anything to do with one another.   It is true that,
though very light, they are also massive objects and should also experience
a gravitational attraction.   They do experience such an attraction, but it
is vastly overwhelmed by electromagnetism.   Gravity is by far the weakest
of the fundamental forces: pathetically weak compared to electromagnetism.
 If you find that statement impossible to believe, try this:  go into your
kitchen and look at your refrigerator.   Do you notice any magnets?  Well,
yes, of course.  The meager electromagnetic force generated by that small
refrigerator magnet is easily overwhelming the gravitational pull of the
entire planet Earth.         Gravity seems strong to us because we happen
to live on a planet stuffed with matter and so the pull becomes
significant.    At the atomic level, the strength of gravitational forces
is negligible.

However, within one of the nebula's dense regions the gravitational force
is growing ever stronger as the region's mass increases.    The
gravitational force eventually molds the gaseous clump into a spherical
shape. Also, as more material accumulates, the pressure within the sphere's
center increases.  The increasing pressure produces higher temperatures in
accordance with the* ideal gas law* which states that the pressure is
directly proportional to the temperature.      As more matter gathers, the
gravity strengthens and the pressure and temperature continue to increase.
   Temperature measures the kinetic energy of particles within any given
system.      The higher the temperature within a substance, the greater the
energy of its constituent parts.

Let's return to our two protons.
As the sphere heats, all the protons within it move increasingly faster.
 While the Coulomb barrier continues to keep Heathcliff and Catherine apart
, their increased velocities enable them to approach each other more
closely prior to their mutual repulsion.   As the sphere heats, the atomic
motions within it become all the more frenetic.    The atoms draw closer
together but still repel.    However, when their separation distance
reduces to an atomic diameter the *strong nuclear force* (SNF) overwhelms
their electrostatic repulsion.    The strongest of the fundamental forces,
the SNF binds subatomic particles together through the interchange of
gluons, elementary particles that serve as nature's most durable adhesive.
   When Heathcliff and Catherine become sufficiently close, the SNF fuses
them together so they become deuterium.       We refer to this process
as *thermonuclear
fusion.*
At this time, the protons are experiencing billions of collisions per
second and the temperature exceeds four million degrees.        These
temperatures do vary, with some protons experiencing much higher
temperatures and some lower.         We must now acknowledge that these
temperatures, though inconceivably high to us, are substantially lower than
the temperatures required to produce fusion in the laboratory.

Fusion occurs in the Sun through a strange process called* quantum
tunneling.  *The fundamental tenet of quantum physics is that these protons
can exhibit both wave like and particle-like behaviors.  Each proton is a
quantum "particle" whose location is a probability function.   About 1 in
every 10^28 particles will "tunnel" beyond the electrostatic barrier to
permit fusion to occur.   Although this frequency seems rare, it is
sufficient to power the Sun.

To explain how fusion generates energy, examine the fusion sequence
featured below.  This sequence, called the proton-proton chain, is the
predominant method of solar energy generation:



[image:
https___blogs-images.forbes.com_ethansiegel_files_2015_06_1000px-FusionintheSun.svg_.png]


   - *STEP 1:*  Two protons combine to form deuterium.
   - *STEP 2:*  One of the protons undergoes beta plus decay to transform
   into a neutron.       In the process it emits a positron and an electron
   neutrino. A *positron* is the antimatter equivalent of an electron, but
   contains a positive charge.  The *electron neutrino* is a nearly
   massless elementary particle generated in solar nuclear reactions.  This
   part of the process is governed by the weak nuclear force, the fundamental
   force that governs radioactive decay.    The positron quickly encounters an
   electron resulting in their mutual annihilation and the emission of *gamma
   rays. *  Gamma radiation is the most energetic radiation along the
   electromagnetic spectrum.
   - *STEP 3:*  The deuterium combines with another proton to form helium-3
   and another gamma ray
   - *STEP 4*:   Most often, two helium-3 nuclei will combine to produce a
   helium-4 nucleus and two protons and 12.86 MeV of energy.  MeV = mega
   electron volts. An electron volt is equal to the work needed to accelerate
   an electron through the potential difference of one volt.        Here we
   are neglecting some of the other proton-proton chains that will also
   produce helium-4.


Some of the constituent matter is converted directly into energy in
accordance to physics' most famous equation

[image: albert-einstein-219675_6401-e1411587981927.jpg]
In this equation, part of Einstein's theory of Special Relativity, *E *=
energy; *m* = mass and *c* = speed of light.  Squared means that you
multiply it by itself.   The ramifications of this relation are
astounding.  Matter is just crystallized energy.      The thermonuclear
fusion reactions with the Sun's core transmute a minuscule amount of this
matter into pure energy.    This energy pressure precisely counterbalances
the gravitational compression within the Sun itself producing a state
called *hydrostatic equilibrium.*

[image: 01.jpg]

While the Sun was taking form out of the nebula, a disc of peripheral
material formed around it.  This extraneous gas and dust coalesced into
planets, moons and the other attendant objects that today continue to
revolve around the Sun.      The Sun has been an active star for about five
billion years.  It contains sufficient core hydrogen reserves to sustain
these hydrogen "burning" reactions for another five billion years.
Tomorrow, we'll learn more about the rest of the sun's life, its eventual
death and much more about the all important concept of luminosity.

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