THE SOUTHWORTH PLANETARIUM 207-780-4249 www.usm.maine.edu/planet
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70 Falmouth Street Portland, Maine 04103 43.6667° N
70.2667° W Altitude: 10 feet below sea level Founded January 1970 Julian
Date: 2459351.18
2020-2021: CXXX
THE DAILY ASTRONOMER
Monday, May 17, 2021
Seeking Space-Time Part I
________________________________
*TIME-SPACE*
Experience the planetarium show that conveys audiences
to various points in space-time: the Big Bang, the end of the
Cretacrous period, a medieval Mayan ritual, the moon landing,
and even into a hypothetical future.
Showings on Wednesday, Thursday, and Friday at 1:00 p.m.
$6.00 - adult; $5.50 - child/senior
Seating is limited. Please e-mail [log in to unmask] or call
207-780-4249 to reserve your space.
____________________________________
The material comprising physical reality, itself. Or, the apparently
rigid, but ultimately malleable, grid work system permeating all that
exists within our Universe. Here, we specify 'our' Universe to
distinguish it from the plethora of other space-times systems that might
exist well out of reach. No matter where one travels - the remotest world
tucked away within the Perseus Super-Cluster, or into the backyard,
spacetime encloses and encompasses: the intangible trinity of depth,
breadth, and width allied with duration or time, pervasive, yet perceptible
only through consciousness, itself deeply mysterious.
[image: space-time-crystal.jpg]
Astronomy involves itself in material investigations, planetary
trajectories, machinations of stars, dynamics of interacting galaxies: the
physics responsible for all that transpires within space-time: the essence
of the cosmos that remains ultimately enigmatic. How can we possibly
study that one aspect of the Universe that eludes our senses? Perhaps
human inquiry, as formidable as its proven to be when trying to demystify
the world, is lamentably unequal to such investigations.
Well, even if space-time ruminations are above our comprehension, humans
throughout the centuries have devoted considerable time and resources to
trying to puzzle it out, The first people whose contemplations remain on
record were ancient Greece's natural philosophers. These bold thinkers,
the predecessors to modern day scientists, asserted that through
rationality the human mind could deduce nature's governing principles.
Zeno of Citium (344-262 BC)*, an early skeptic, insisted that neither space
nor time were real as material objects could not act on them. Ironically,
this earliest presumption would only be contradicted 2200 years later.
Zeno taught that empty space was necessarily not existent as it had no
meaning whatsoever.
Archytas (428-347 BC) reasoned that space had to exist as evidenced by the
ability of a person to move an object from one point to the other. Were
space non-existent, motion would become impossible. A few centuries
later, Lucretius (99-55 BC) wrote similarly about time, but claimed that it
did not exist by itself, but was made manifest through observations of
moving things.
[image:
resized_image2_ae7b73796e98b841b452699bf31182f7.jpg.webp]
*Archytas*
Aristotle ( 384-322 BC), one of the few truly well known Greek
philosophers, was contemptuous of his predecessors' attempts to elucidate
the principles of space and time. He thought that space was defined
solely by occupying objects. If you place a chair on the floor, space
assumes the identity of a chair on a floor. Here, space was perceived as
being as adaptable as fluid that shaped itself in accordance with whatever
cup contained it. Here, as an aside, we should mention that Aristotle was
similarly disdainful of the atomists, the philosophers who believed that
matter was reducible to a combination of indivisible particles. As
Aristotle rose to eminence, both in life and posthumously, his theories
prevailed over the contradicting views of his forebears and
contemporaries. The atomic theory, championed most notably by Democritus,
was dismissed, only to find confirmation with the advent of modern
chemistry. His views on space also rose in popular estimation. Perhaps
most pertinent to our discussion is his insistence that reality be divided
into the ultimate 'above,' the heavens and the ultimate below, 'the Earth.'
presumed to occupy its center.
Claudius Ptolemy (85 - 165 CE), deemed by many scholars as history's most
mathematically gifted charlatan, imposed a series of clever constructs to
quantify Aristotle's treatise of an inert world surrounded by a mobile, but
otherwise immutable heaven. Ptolemy's epicycles and deferents, along
which planets described complex prograde and retrograde loops around a
static Earth, were ingenious contrivances, but inherently inaccurate, as
Ptolemy, himself, realized, hence his inclusion false figures and planetary
configuration into his proleptic almanac (one that pre-dates the time of
compilation.) Ptolemy produced a solar system model sufficiently
workable to be taught as fact for centuries. He had little, however, to
say about the nature of space, itself, apart from adorning it with his
handy lattice work.
[image: 2-whatisthehel.jpg]
Aristotle's view that objects defined space went mostly unchallenged for
more than a thousand years. In fact, Italian Astronomer Galileo
Galilei (1564-1642) didn't perturb this space paradigm as much as one would
have thought he would have, he being so instrumental in demonstrating that
the Sun, not Earth, defined the solar system's center. As far as space,
itself, was concerned, Galileo almost confirmed the absolutist notion that
the stars rested in space, as assuredly as the Sun reposed inertly in its
own niche. Galileo actually coined the phrase "absolute motion." an
ironic distinction for one who defied an inquisition with the bold
proclamation "but, it does move,' here in reference to the rotating and
revolving Earth.
Isaac Newton (1642-1727), co-discover of the Calculus and classical
physics, provided the absolutists with a physical framework. His succinct
phrase, "Absolute, true and mathematical time, in and of itself, and from
its own nature, flows without relation to anything external." Of
space, he was equally insistent that it existed independent of time and
also of those objects that moved and remained stagnant within it.
Newton established this notion by developing a revolutionary, though
mechanistic, model of the Universe. He perceived the cosmos as a large
clockwork mechanism in which every element's position and speed could be
predicted provided that their earlier conditions were known. Through the
power of rigorous mathematical calculations, Newton demonstrated how Earth
bound objects fell, the Moon revolved and the planet's moved.
Newtonian mechanics, as was known, proved so effective at describing
physical phenomena that it held sway over physical science for nearly two
centuries. Rigid, three dimensional space and time, the progression that
caused all change and dynamism. Neither were related and neither were
changeable. They existed, perhaps forever and would always exist in
accordance with divine intention.
That notion worked so splendidly....at least for awhile....
Part II tomorrow
*This fellow is not the same philosopher responsible for Zeno's paradox.
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