THE SOUTHWORTH PLANETARIUM

207-780-4249   www.usm.maine.edu/planet

70 Falmouth Street   Portland, Maine 04103

43.6667° N                   70.2667° W 

Altitude:  10 feet below sea level

Founded January 1970

Julian date: 2458785.16

2019-2020:  XLI

                 "Keeping a watchful eye on a complex sky"

THE DAILY ASTRONOMER
Tuesday, October 29, 2019

Our Eternal Components

One need only reflect on the lives of wit-disordered metaphysical  philosophers to recognize the peril inherent in pondering eternity.   Our otherwise miraculous minds seem ill equipped for such profound contemplations.    We tend to derive comfort from the notion that all things, including the biggest thing of all, draws to a complete ending just as it arose from a specific beginning.       That we could be sitting, driving, lying down or otherwise making a nuisance of ourselves in a cosmos that will literally persist  eternally  is not only disquieting, but alarming.          Could our comparatively brief lives be negligible fragments of forever?

The notion of an eternal Universe, considered by philosophers both ancient and modern, arose anew out of the Dark Energy Theory, dating from the mid 1990s:  the theory which asserts that a mysterious force operating over cosmological distances could be accelerating the Universal expansion to ever greater velocities.    Dark Energy theorists predicate this theory on the observation that Type Ia Supernova are receding faster than they should.      Type  Ia supernovae are explosions that occur when a white dwarf companion of a giant star accumulates enough material from the giant through tidal forces to cause the white dwarf to explode.   Remember yesterday we mentioned that electron degeneracy -the mutual repulsion of the white dwarf's electrons- prevents the white dwarf from collapsing under its own gravity.    If the white dwarf's mass exceeds 1.4 solar masses, the gravity will overwhelm the degeneracy pressure.  When the white dwarf companion gathers enough gases to  surpass this limit, the white dwarf will collapse and then explode.    Unlike Type II supernova that can result from the explosions of many different types of highly massive stars,  the energy release from each Type Ia supernova should be equal to the release of any other such explosion.  For this reason, these consistently brilliant explosions serve as reliable distance indicators on the vas intergalactic scale.  

Type Ia Supernova:   the distance markers over

vast reaches of deep space.

When the Big Bang Theory was first posited in the early 20th century, scientists first considered time to have a specific beginning.  The main question concerned the Universe's ultimate fate: would it expand forever or would the matter within the cosmos exert an impeding force on the expansion so as to either halt the expansion or, more likely, reverse it to produce an implosion, playfully dubbed "the big crunch" that would precede the expansion of another Universe.   The Dark Energy model, though not wholly resolved, tells us that our is an eternal cosmos.

The implications of this theory also relate to you.  Yes, we mean you.    Regard your fingertips or toes or any other part of the body in your view.    What do you notice?  Or, more correctly, what don't you notice:  the constituent atoms comprising those parts?  The carbon atoms, iron atoms, and the myriad other molecules and cellular structures that conspire together to form you.       These elements were, at one time, simpler: the hydrogen and helium that crystallized from the radiant energy pervading the infant Universe.      The carbon, iron, oxygen and other elements were forged from the first generation of stars that transmuted the light elements into heavier ones.    Eventually, the star that generated these elements exploded as a Type II Supernova.  This explosion fused the elements heavier than iron and then chemically enriched the surrounding gaseous regions with these "metals" to produce the primordial cloud from which the Sun and its attendant bodies formed.   These particles would eventually become incorporated into the life forms: from the simplest bacteria to the ultra-complex human. In other words, you.

We lose more than a billion cells an hour, only to have them replaced by others.  Elements in; elements out.  The oxygen we inhale, the carbon dioxide we exhale; the wicking away of our old selves; the reconstitution of our new ones.    The elements that comprise us now will persist for billions of years; just as they did for the aeons preceding our births.     In fact, if the Dark Energy theorists are to be believed, the Universe could possibly persists forever, provided the acceleration won't dismantle the Universe entire in a "big rip."    If the Universe holds together, we are literally formed of eternal particles that, like the filaments of a cirrus cloud, spent a rapid moment as us before moving on to other endeavors.    We are therefore not only made of such little matter as to be insubstantial, we are fleeting of duration and of ever changing form.

To think that looking up could result in such an inward perspective. 

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