THE SOUTHWORTH PLANETARIUM
University of Southern Maine
96 Falmouth Street
Portland, Maine 04103
usm.maine.edu/planet
(207) 780-4249


THE WANDERING ASTRONOMER
Thursday, January  25, 2024
April Eclipse I: The Unfathomable Worlds

*[74 DAYS UNTIL THE APRIL 8TH ECLIPSE]*

Let's begin this eclipse series with a simple and sobering
acknowledgement.    We'll never fathom the Sun, Earth and Moon.  Not for
even a nanosecond.

It's certainly true that we can describe them and evaluate them
intellectually.   For instance, the Sun's diameter extends over 865,000
miles and, if hollowed out, could accommodate 1.2 million Earth-sized
worlds.    We also know that this hefty behemoth is a weighty sphere.
 Plop the Sun on the left side of the scale and one would need to pile
333,000 Earths on the right to attain equilibrium.     Also, and perhaps
most importantly, we recognize that the Sun is a prodigious energy
generator.  Let's imagine for a disquieting moment that our local power
company ran the Sun for just one second and then stuck YOU with the bill.
  You would owe an amount equal to America's Gross National Product...over
the next ten million years.      Sol emits that much energy every time we
blink.  Earth receives only one billionth of that copious outflow.  To put
this fraction into perspective, one second equals one billionth of 32
years!   As miniscule a portion as this represents, it's enough to sustain
our world.  And, finally, we're aware of its longevity.    The Sun awakened
out of its birth nebula approximately five billion years ago and will
continue to glow with ever increasing brilliancy for billions of years to
come.

Humans have done the work necessary to understand the Sun: from the
Copernican model which set the Sun in its proper place, to the Newtonian
mathematics that ascertained its mass to the 18th century transit of Venus
voyages that determined its distance -and therefore size- to the geological
excavations that measured Earth's age, and by extension that of the Sun, to
the nuclear physics that demystified its energy production mechanisms.
We're dwarfed by its proportions, dazzled by its brilliancy, and comforted
by the assurance that it will continue to both retain Earth with its
gravity while bestowing ample quantities of radiant energy onto it long
after we homo sapiens have vaporized ourselves into the ages.

Our scientific reckonings notwithstanding, however, we don't know the Sun.
It's far too remote and its proportions are well beyond the range of our
intuition.      For instance, people who have never visited Manhattan still
know that the city is a sleepless, bustling, ferociously energetic nuclear
reactor of a town.      However, visiting Gotham lends one a true
appreciation of its power and dynamism.     The intellectual
acknowledgement transmutes into an intuitive appreciation.       The Sun,
which is many, many orders of magnitude grander than the Big Apple, will
forever remain outside our intuition.

So, too, for that matter will even the comparatively teeny motes of Earth
and the moon remain unfathomable.   It might not be remote -look down,
there it is- but Earth's proportions are such that we'd need to ascend to a
height of nearly ten miles to even notice the planet's curvature.

As for the moon: although its distance from us varies, it never ventures
closer to us than about 238,000 miles.  One could neatly line up 30 Earths
within the space that separates Earth from its one natural satellite.
 Though it might well appear as a silvered orb looming large just above the
distant summit, it's actually a small dark world far removed from terra
firma.        In fact, the moon is 400 times smaller than the Sun.
 However, it also is nearly 400 times closer to us than our parent star.
    Consequently, the Sun and moon appear equally sized from our
perspective and so, on occasion, the latter can move directly in front of
and entirely cover the former to produce a total solar eclipse, such as the
one that will happen on April 8th.

For the next couple of months, we will be delving into every possible
detail related to this event: the dynamics, the history, the math,
mythology and other aspects.      As we proceed, however, we shouldn't
forget that we're observing the chance alignment of celestial spheres;
spheres of grand proportions located at unfathomable distances.          As
with everything in life from people to oceans to clouds forms, we'll be
reacting only to our thoughts about these worlds, not to the worlds
themselves.       Provided however that we at least acknowledge that the
celestial sphere remains the abode of the gods we'll begin to understand
the true scope of the event we're preparing to observe.

On April Eclipse 2:   Just a Simple Syzygy