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: 2458875.16
2019-2020:  XCII
               "Outer space is no place for a person of breeding."
                                    -Lady Violet Bonham-Carter


THE DAILY ASTRONOMER
Monday, January 27, 2020
Preparing for Galactic Tick Day!

Well, yes, now we're languishing in the hollows of the holiday doldrums.  The festival holiday celebrations of the year's end and beginnings have been over for nearly a month.   Except for the two Saint Days, Valentine and Patrick, we'll experience a depressing dearth of diverting holidays for quite awhile.    Yet, we are happy to announce the establishment of a relatively new holiday:  Galactic Tick Day!   The celebration of our motion through the Milky Way Galaxy.      We've included the following announcement:

Stop!
Whatever you do in the next few minutes, do NOT make any plans for March 21, 2020.    Why, you might ask?    Well,  March 21, 2020 is the next Galactic Tick Day: an astronomical holiday devoted to celebrating existence in the Milky Way Galaxy.     Yes, we know you're still a bit perplexed and by now you might have already tossed this missive into the desktop recycle bin, where it will be propelled in a flutter to the oblivion of Morpheus.   If you're still reading, we'll explain:

The Solar System is roaring through the Milky Way Galaxy at a steady clip of 143 miles per second!    By the time you finish reading this one single, unremarkable, not particularly inspiring, grammatically questionable, ultimately pointless sentence, the solar system will have moved about 1600 miles through the Milky Way, equal to the distance separating the sun-baked shores of Miami, Florida from  the Mammoth-trod tundras of Portland, Maine.  While that speed would certainly topple the tea cups in our terrestrial realm, it is almost glacial by galactic standards.   In fact, the solar system requires precisely 633.7 days (1.761 years) to complete a single centi-arcsecond through the galaxy.*

Every 633.7 days (1.761 years) we pass another tick mark in the galaxy. In other words, our Sun and its attendant planets, moons, comets, cities and people progress another centi-arc second around the Milky Way Galaxy.   Granted, that doesn't constitute a great progression. However, as we require about 225 million Earth years to complete one circuit, one shouldn't expect to go far in less than two years.     Naturally, we celebrate Galactic Tick Day every 633.7 days.  The previous observance was on June 26, 2018.  (Yes, we missed it because we only learned about the accursed holiday this morning.)  Now, if we engage our formidable skills -i.e. consult the official Galactic Tick Day Web-site (www.galactictick.com)- we can calculate that the next Galactic Tick Day will occur on March 21, 2020.**

The March 21, 2020 Galactic Tick Day will be the 237th Galactic Tick Day since the first one which occurred exactly 633.7 days after October 2, 1608, the date when Dutch lensmaker Hans Lippershey was said to have filed for the telescope.***    Now, nobody at the time celebrated the holiday because (1) nobody really knew about the galaxy, itself, let alone our motion through it and (2) it was only developed in 2016 by California entrepreneur Dave Sneider.  He wanted to help society appreciate the magnificence of the galaxy by designating a holiday commemorating our motion through it.    

So, mark your calendars now because, by Heavens and high water, the Southworth Planetarium**** will be open for as much bacchanal debauchery as our delicate constitutions can withstand on the next Galactic Tick Day!


*Yes, we knew you were eager for some geometry and needed a fix.   First, we have a simple circle:

onedegree.gif

Each circle contains 360 degrees.     Each degree can be equally subdivided into 60 arc minutes.  Each of those arc minutes can be equally subdivided into 60 arc seconds.  And, each of those arc seconds can be equally subdivided into 100 centi arc-seconds.    Now, in theory, we can subdivide those angles ad infinitum until we reach an angle so infinitesimally small it could produce its own Universe.   However, for the purposes of this article, we can safely stop at the centi arc second level. 

**Yes, we knew you were eager for an astronomy fix, as well.    In the Eastern time zone, the Vernal Equinox will NOT occur on March 21, 2020. Instead, we'll reach the first day of astronomical spring just before midnight on March 19, 2020.  Therefore, we will not experience the coincidence of the vernal equinox and Galactic Tick Day, which is a relief as such confluences tend to pulverize sacred statues.  

***And, now for the history fix!   No, Galileo did not invent the telescope. Hans Lippershey invented this miraculous device to spot ships as sea.  Galileo had the inspired idea of turning it skyward. 

Hoven_Galileo.jpg
An artistic depiction of Galileo Galilei aggravating the
devil out of Pope Urbain VIII with his annoying
"But it does move" blather.  

*****So, today, I explained the notion of Galactic Tick Day to the esteemed Planetarium director, Dr. Jerry LaSala.  As he is an ivy-league educated astrophysicist, I have to hand hold him a lot through certain concepts.   He knew nothing of Galactic Tick Day. After explaining the entire idea with charts, illustrations and even a superfluous decoration, he regarded me with interest and said, "I've been meaning to ask:  what do you actually do all day?"


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