THE SOUTHWORTH PLANETARIUM
207-780-4249         www.usm.maine.edu/planet
70 Falmouth Street     Portland, Maine 04103
                "Gee....we wonder what the number one movie this weekend
will be?"



THE DAILY ASTRONOMER
Wednesday, December 16, 2015
Star Wars Astronomy

------------------------------------
Two personal notes:

Happy Birthday, Brother Richard!

       ++++

As for the name "change," this new e-mail system is using my first name,
James, instead of my middle name, Edward, which I have used as my primary
name since I was 15. (My wonderful mother still thinks its a phase I'm
going through.)
------------------------------------

We just cannot resist any type of hype.  This week, the planet's seven
billion plus inhabitants are all camping out in front of theaters anxiously
awaiting the opening night for Star Wars VII "The Force Awakens."  From the
children desperately engaged in light saber battles to the dyspeptic uncle
who, having seen Darth Vader's face on a espresso flavored Coffee Mate
container, now thinks the world could only be improved with a proximate
supernova, Star Wars pervades the planet and nobody can escape from it.
The current mania is somewhat reminiscent of the hysteria that attended the
1977 movie "A New Hope."    Therefore, we want to join in the "fun," with a
DA article pertaining to both the science and the fiction behind the Star
Wars Universe.      After all, Star Wars hasn't received nearly enough
attention lately.

A LONG TIME AGO IN A GALAXY FAR, FAR AWAY
This famous opening line prompts the question:  could alien life have
existed a long, long time ago?   We know that advanced life forms cannot
exist without an abundance of complex molecules that, themselves, are
composed of "heavy elements," such as oxygen, phosphorous, carbon, and
others.*      Only the simplest elements, primarily hydrogen and helium,
existed during the Universe's infancy.     The first generation of stars
manufactured the "metals," defined astronomically as the elements heavier
than helium.   These stars, being the highly massive population III, would
have exploded as supernovae, thereby enriching the galaxy with an infusion
of all the heavy elements.     This chemically rich material would have
then become incorporated into other star/planet systems. On these heavy
element laden planets the first life might have developed. The life might
have evolved from the simplest prokaryotic cells to a galaxy-dominating
empire. We assume, based on Earth's evolutionary time frame, that such a
process would have required at least five to six billion years.   As humans
haven't yet become a star faring race, we haven't the faintest idea how
long such a progression would require.   After all, humans haven't yet
ventured more than a quarter of a million miles from Earth. We're a long
way from zipping between star systems.

The upshot of it all is that the Universe might well have produced mighty
empires in distant galaxies that have long since vanished.  We can't know
if they existed, of course, but we can at least be confident that the
necessary chemical building blocks have existed in the cosmos for billions
of years.

The assumption we've made is that we're actually now observing the "Star
Wars" galaxy as it was when all that transpired on film was happening.   If
it all occurred a billion years ago, the galaxy is a billion light years
away from us.    Then, again, there is a slight possibility that we're over
thinking it.


LASER GUNS
As impressive as these weapons appear, we certainly hope they weren't
expensive, because they truly don't work well.     Let's assume you are
surrounded by a doom of storm troopers,** but, fortunately, you're armed
with a laser gun.   You fire indiscriminately at your assailants, some of
whom deftly dodge the rays, while others are slain by them.    Then, of
course, you realize: these accursed beams are moving very slowly!   A beam
of light travels at more than 186,000 miles a second in a vacuum and at
nearly the same speed in air.  If the storm trooper can avoid the beam, it
is traveling thousands of times slower than lasers actually travel.     It
is true that a laser pulse can fry a nervous system and make short work of
storm troopers, even though they are completely enclosed in the most
expensive armor the Empire can buy.   However,  someone should tell the
Empire engineers to remove the anchors from the beams because the light is
moving like its 145 years old and doesn't really care any more.

WARP SPEED
Remember that scene when Han Solo was piloting the Millennium Falcon and
then floored it to light speed?  Well, how could one forget!    The
pinpoint stars rapidly elongated to luminous lines converging to the middle
distance.    If I might include a brief personal recollection.   I remember
my brother, Richard, took me to see the 1977 Star Wars movie and just
before Han et al accelerated to warp speed, he nudged me and said, "Watch
this!"    I did and was, of course, astonished and said, to the delight of
nearby viewers, "Wow, Dic, tell him to do that again!"    Now, had I known
then what I pretend to know now, I would have instead said, while
pedantically waggling an index finger, "Now, Richard, you realize that if
those oddly dressed people were actually traveling on board a vessel
traveling at light speed, they wouldn't be able to converse because time
stops at light speed.   The Theory of Special Relativity tells us that time
dilates on any moving object and that dilation relates directly to the
speed.  The faster the vessel, the greater the dilation.   If the
Millennium Falcon had achieved light speed, time would stop.   Of course,
the ship's mass also increases with increased speed, so its mass would
essentially become infinite at light speed, which would preclude it from
attaining that velocity."

And, we agree....the "Wow, Dic, tell him to do that again!"  was the far
less annoying thing to say.


RULING THE GALAXY
Alexander the Great would have liked this: he would never have run of out
worlds to conquer.   In the Star Wars Universe, the Empire ruled an entire
galaxy with a particularly hard iron fist.     Such domination would have
necessitated the development of a particularly advanced hyperspace travel
and communication infrastructure.     Let's imagine that someone wants to
govern the Milky Way Galaxy.   According to recent estimates, our one
galaxy contains more than 200 billion stars and, perhaps, an equal or even
greater number of planets.    Quite a lot of real estate to have under
one's dominion.  One would require untold trillions of minions to do one's
bidding and one would also need the means by which to convey the latest
dictates instantaneously to all your myriad underlings.     If you were
constrained by light speed, you wouldn't be able to maintain order.  Let's
just say a planet full of troublesome upstarts on the other side of the
galaxy starts to go all Libertarian on you and resists the Empire.    You
decide to send them a placating message of "Shut up and deal with it!" Even
if the message travels at light speed, it would require tens of thousands
of years to reach them, by which time the original agitators will have long
since perished. So, too, would you.

Of course, there is always the Von Neumann machine method.     An advanced
alien race constructs a vessel capable of traversing great distances and
self replication.  As it travels through the galaxy, it visits various
planets and mines raw materials from which it manufacturers components to
construct a copy of itself.  Once completed,  this copy proceeds to also
make copies of itself.  These, in turn, would be self replicating so that
after a comparatively brief time, perhaps 200 million years, Von Neumann
drones could be swarming through the galaxy.     Let's be cheerful and
further assume they've also been programmed to conquer inferior races
(i.e.  all of us) and, being incapable of empathy, have no compunction
about slaying the disobedient.    Perhaps through the agency of these
surrogates, a race could conceivably become both prevalent and
domineering.   Good luck collecting the taxes, though!


Then again, maybe the Star Wars franchise is just brilliant science fiction
designed to delight audiences, inflame imaginations, and enrich the movie
studios.  That is just fine by us because there is nothing more electric
and elating than escapist escapades into the remotest hollows of outer
space.




*The vast majority of life forms consist primarily of six elements: carbon,
hydrogen, nitrogen, oxygen, phosphorus and sulfur.   As we lack any
knowledge of extra terrestrial life forms, we cannot know if these elements
will be as predominant in alien beings.

**Yes, there are collective nouns specific to storm troopers and yes, I
actually took the time to look it up and yes, somebody else took the time
to make one up and then post it on line and yes, if you were a socially
awkward geek type you'd also have plenty of spare time at night to learn
collective noun words such as a doom of storm troopers, a shortage of
dwarves, a debauchery of hedonists, a metamorphosis of ovoids, a wiggle of
Elvis impersonators (you can't unsee that), a tabula rasa of empiricists
and, G-d help us, a handful of palm readers.