Happy Equinox !

And, you know, nothing's perfect

Happy Equinox !

As of 5:40 p.m. Monday 20 March, Light has overcome Darkness everywhere in the Northern Hemisphere — the days are now longer than the nights. The rate-of-change of the day’s length of time, about 2 1/2 minutes per day here in Southern Indiana, is now decreasing and will continue to do so until the Summer Solstice on Jun 21st when the days will be almost 15 hours long¹. Christians will celebrate this astronomical event on the first Sun Day following the first Full Moon after the Equinox, Easter (Sun April 09)². Sorry if you live south of the equator — for you the Darkness has overcome the Light, but I think you still must Celebrate Easter on the same date, and I won’t even ask how Santa gets his sleigh to your homes 3 days after the beginning of your Summer.

I celebrated this astronomical event with my own Pagan Ritual: I located an out-of-the-way East-West country road in Decatur County, IN (W County Rd 850 South, see Fig. 1) where a friend I travelled (with a couple chairs, little table, a nice bottle of wine, two types of cheese, and some mixed nuts) to watch the sun set exactly in the middle of the road when looking west at 7:57 p.m. EST, the “official” time of the sunset.

Figure 1. W County Rd 850 South in Greensburg IN highlighted with a Blue Rectangle. There’s not much traffic on a country road dead-ending into another country road in the middle of a “corn dessert”, so we could set up our table and chairs right in the road.

Unfortunately, things did not go exactly as planned. As shown in Fig. 2, while the sun was almost directly at the end of the road at 7:44:40 p.m., it set north of the road (to the right in the picture) at 7:50:34 as shown if Fig. 3.

Fig. 2. Photo at 7:44:40 p.m. The sun is almost directly over the road, but has not yet set.

Fig. 3. Photo at 7:50:34 p.m. The sun set north of the road. Epic Fail.

And, you know, Nothing’s Perfect

• Early in the spring of 1820 the Federal government sent out several squads of surveyors to lay out the "New Purchase," lands acquired from the Delaware Indians by the treaty of St Mary's (1819), embracing all of the eastern and central part of the present state of Indiana.³ Apparently the surveyors had anachronistically mis-calibrated their GPS units, so the E-W lines are about 0.8 degrees off from true East as can be seen from a careful inspection of the road with respect to the rectangular box in Fig. 1.⁴ On might wonder about the myriad a small land disputes this led to over the last 200 years.

• And, if you look at the “official” length of day for 20 March in Southern Indiana, you will see it is NOT 12 hours, but rather 12 hours and 8 minutes. That is because “sunrise” is defined as when the leading edge (not center) of the Sun’s disk rises above the horizon, and the “sunset” is defined as when the trailing edge (not center) of the Sun’s disk falls below the horizon.

• AND, it was kind of cold, so instead of sitting on our chairs, we huddled in the car. But, hey, no one died (neither of us were “Vax’d”), at least not yet.

1. I’ve been in Sweden at least a couple of times at the Summer Solstice — there it gets to be twilight from about 10 p.m. to 2 a.m. — one can easily walk in the woods with no flashlight at midnight. I’ve never been there around the Winter Solstice and have no desire to do so, except perhaps to see the Aurora Borealis while sitting in a Hot Tub.

2. The Lunar Cycle is about 29.5 days, so Easter can jump around on the Calendar by as much as 36 or 37 days.

3. https://genealogytrails.com/ind/decatur/history.html

4. The magnetic declination (deviation of Magnetic North to True North varies from 0 to 5 degrees across the State of Indiana, and is 5 degrees in this area, so they at least had their compasses pretty-well calibrated. On the NW and NE coasts of the U.S., the declination is almost 20 degrees, East and West, respectively.