Join mblatch for coffee, food, and general socializing at the
exact moment he turns 33.333333 years old.
Event Date: Wednesday, May 27, 2009
Event Location: Rockn' Joe's Cafe, Westfield,
NJ
Event Time: 8:00 - 10:00 PM
The One-Third Century Mark: 9:21:42 PM EDT
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See below for special
event puzzle (optional).
No gifts or cards required. Just your company
to help celebrate this milestone.
In attempting to determine the exact moment that I would round
the one-third of a century mark, I learned that there are several
different definitions of a year. While most people are familiar
with the concept of the calendar year, which is the
time between two dates with the same name (i.e. May 27, 2008 to May
27, 2009), there are many different definitions of a year based on
the movement of the Earth and Sun.
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The Julian year,
a reform of the Roman calendar, was introduced by Julius
Caesar in 46 BC, and came into force in 45 BC (709 ab urbe
condita). It was chosen after consultation with the astronomer
Sosigenes of Alexandria and was probably designed to
approximate the tropical year, known at least since
Hipparchus. It has a regular year of 365 days divided into 12
months, and a leap day is added to February every four years.
The Julian calendar remained in use into the 20th century in
some countries, but it has generally been replaced by the
modern Gregorian calendar. It is still used by the Berber
people of North Africa, on Mount Athos, and by many national
Orthodox churches.
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The Gregorian year
is the currently accepted international civil calendar. This
calendar was first proposed by the Calabrian doctor Aloysius
Lilius, and decreed by Pope Gregory XIII, after whom it was
named, on 24 February 1582 by the papal bull Inter
gravissimas. It is a reform of the earlier Julian calendar and
attempts to keep the vernal equinox on or soon before March
21. The average length of the Julian year is slightly longer
than the time it takes the Earth to complete one orbit around
the Sun, so over the centuries that the Julian calendar was in
use, several days of error had accumulated in the calendar so
that the dates were out of synch with astronomical
observations. Countries throughout the world adopted this
calendar over a 300 year period, with the last being Turkey in
1926.
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A sidereal year
is the time taken by the Earth to orbit the Sun once and
return to the same position with respect to the fixed stars.
As the Earth orbits the Sun, the apparent position of the Sun
against the stars gradually moves along the ecliptic, passing
through the twelve traditional constellations of the zodiac,
and returning to its starting point. This motion is difficult
to observe directly because the stars cannot be seen when the
Sun is in the sky. However, if one looks regularly at the sky
before dawn, the annual motion is very noticeable.
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The tropical year
is the time taken for the Earth to complete one revolution
with respect to the framework provided by the intersection of
the ecliptic and the plane of the equator. The exact length of
a tropical year slightly depends on the chosen starting point:
for example the vernal equinox year is the time
between successive vernal equinoxes. The tropical year is
shorter than the sidereal year because of the precession of
the equinoxes.
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The anomalistic
year is the time taken for the Earth to complete one
revolution with respect to its apsides. The orbit of the Earth
is elliptical; the extreme points, called apsides, are the
perihelion, where the Earth is closest to the Sun, and the
aphelion, where the Earth is farthest from the Sun. The
anomalistic year is usually defined as the time between two
successive perihelion passages. The anomalistic year is
slightly longer than the sidereal year because of the
precession of the apsides (or anomalistic
precession). |
Optional Event
Puzzle: What kind of mblatch cache would this be without
some sort of puzzle?? Why, no cache at all I tell you!!
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All of those that correctly answer the puzzle question will be
entered into a random drawing for an unactivated geocoin
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So what is the puzzle question? Given the exact one third
century mark listed above, calculate the exact moment that mblatch
entered the world. Now, you may ask, "mblatch, after your lengthy
lesson on the different definitions of a year, which definition do
I use in my calculation?" The answer is....all of them.
The exact one-third century mark
is calculated using the average of the lengths of the Julian,
Gregorian, siderial, mean tropical, anomalistic, and vernal
equinox years, calculated out to as many decimal places as you
can find for each.
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The exact time of mblatch's arrival has been adjusted for
sunspots, wind speed, moon phase, the hyperfine electronic
transitions of the Cesium-133 atom, and the accuracy of clocks in
1976 as determined by the time on his birth certificate. Oh, and
don't forget to adjust for daylight savings time. Since mblatch's
birthday is in the dead of winter, he expects that all answers will
be presented in EST.
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