Tuesday, March 20, 2018

Spring Equinox 2018

The earth will pass through the point of March equinox, which is spring equinox in the northern hemisphere, today at 0915 Pacific, or 1215 Eastern, which is 1615 GMT / UTC.

I have made the above video in order to help us to visualize the sun's path through the zodiac throughout the year (which is a function of the changing line-of-sight between earth and sun as we orbit around the sun in our annual cycle), and also the sun's path higher and lower through the sky throughout the year (which is a function of the tilt of earth's axis, which causes the path of the sun through the sky to be higher or lower for us based on where we are in the orbit and the orientation of the axis relative to the sun).

The video gives a "time-lapse" style animation of the sun's position from the perspective of a viewer on earth in the northern hemisphere, seen at noon each day (to help illustrate the change in elevation of the sun's arc across the sky as we go through the seasons).

The background of stars (which is obviously not visible at noon under normal conditions) has been revealed using the planetarium app (stellarium.org) in order to show the sun's position relative to the zodiac constellations.

The sun's elevation will grow higher and higher after we pass winter solstice and progress towards summer solstice, where it reaches maximum elevation, and then it will stop getting higher and begin to get lower in the sky as we progress from summer solstice to winter solstice.

The point of equinox occurs twice a year when the sun's path crosses through the celestial equator, once on the way "down" from the summer solstice on the way to the winter solstice (when we pass the point of fall equinox) and then once again on the way back up from winter solstice towards summer solstice (the spring equinox, which we will pass through today).

This short video may help you to visualize what is taking place. In the video, you can see all the way down to the south celestial pole, because the earth has been rendered "transparent" or invisible, even though the perspective shown is still that of an observer in the northern hemisphere. The sun at noon each day will move through the constellations of the zodiac as earth progresses day-by-day throughout the year (moving through them at a rate of about one per month). This changing of the background constellation is a function of the "line-of-sight" between earth and sun changing as we make our orbital circle (ellipse) around the sun.

Numerous previous posts have used various diagrams and metaphors to explain the mechanics of the solstices and equinoxes -- you can find those by using the search function of this blog and looking for the words "equinox" and "solstice."

Also, my most recently-published book, Ancient Myths, Ancient Wisdom, which preserves in physical book format a selection of blog posts from the first one thousand posts of this blog, begins with a section of essays discussing celestial mechanics, and some of the connections of these heavenly cycles to the world's ancient myths.

The spring equinox is an extremely important point on the cycle of the earth's annual dance with the sun, incorporated into many memorable myths and sacred stories around the world, as well as into many of the alignments of ancient monuments which survive to this day.

It also marked the beginning of many (though not all) of the sacred calendars of ancient cultures.

For more on the spiritual significance with which this point on the annual cycle may have been invested or imbued by the world's ancient myths and teachings, see for example this previous post from 2015 entitled "Easter: the Birth-Day of the Gods" (after the title of a lecture by Alvin Boyd Kuhn).

I hope that you will have the opportunity to contemplate some of the meaning with which this day was perceived by our ancient ancestors (from virtually every culture on every inhabited continent and island on our planet). And in doing so, we connect ourselves to those who contemplated this day and that meaning in equinoxes past, stretching back through the millennia into the mists of prehistory.