Mar 21 2007

Happy Vernal Equinox!

It’s my favorite day of the year. The day of “equal night” when the sun spends an equal amount of time above and below the horizon everywhere on earth, when the sun crosses the celestial equator and the earth’s axis is perpendicular to the sun. In the Northern Hemisphere it is the first day of spring and in the Southern Hemisphere the first day of autumn. For me it means the end of winter weather and likely a good 6-7 months before it returns.

Humans generally like to mark the passing of time with arbitrary conventions. The equinoxes and solstices, at least, have an objective reality in astronomy and are useful in predicting the seasons.

There is one bit of persistent nonsense that haunts the vernal equinox – the idea that on this day and this day only one can stand an egg on its end. The idea has its origin in Chinese tradition – although the Chinese legend states that an egg can be balanced on end on the first day of spring, which occurs about 6 weeks before the vernal equinox in the Chinese calendar. The idea was imported to the West by way of a 1945 Life Magazine article – and the date quickly migrated to the Western convention of the first day of spring being on the vernal equinox.

This has led numerous people over the years to test the notion by trying to balance an egg on its end on the vernal equinox, which to the surprise of some they can. Of course, this does not test the claim at all – you would need to compare egg balancing success on the equinox to other days of the year. It should come as no surprise that you can balance an egg equally well on any day of the year. The trick is to use a slightly rough surface that will have small imperfections that can be used to prop the egg upright. Alternatively, the end of the egg can be flattened slightly (which may happen inadvertently from making multiple attempts). On any day of the year you cannot balance a pristine egg (raw or hardboiled) on a smooth surface.

Fortunately, I think this is one myth that is truly on the way out – if the internet is to be any guide. My search for “equinox” and “egg” on google led to many websites, almost of all the first 30 or so were skeptical of the egg balancing claim or were dedicated to exposing it as a myth. Our friend, Phil Plait of Bad Astronomy, had many hits as he has taken aim at this particular bit of folklore many times in the past.

The equinoxes also have significance in astrology, although the precession of the equinoxes presents a significant problem for sun-based astrology. The axis of the earth is rotating with a cycle of about 25,800 years. This causes the sun to shift its position relative to the stars and time of year. So the constellation in which the sun appears shifts over time. In the last 2000 years the sun has shifted a full zodiac sign – so if you are an Aires you were not born when the sun was actually in the constellation of Aires. Of course such astronomical details are the least of the conceptual problems with astrology – an ancient superstitious system of pure magical thinking and pattern seeking.

Many religions have holiday celebrations on or around the vernal equinox, most of which probably derive from pagan holy days. This includes the modern manifestation of paganism in the religion of Wicca.

So you can take your pick – you can spend the day trying to balance eggs on end, correcting your astrological charts for precession, or dancing around naked in the woods. I think I’ll just start packing my sweaters away and start looking forward to some warmer weather.

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