After a cool winter in Kern County, springtime is about to bud. Actually, quite a bit of budding has already occurred in the south valley with flowers making their appearance between the valley floor and about the 3,000 foot level in our mountains. It promises to be a beautiful floral season.

But have you noticed that the first day of spring has gotten earlier. I don’t mean due to the weather or because of leap year. No, the vernal equinox during which the sun’s most direct rays move north of the equator and spring officially begins is actually coming earlier than when you were young (assuming you’re an adult). Indeed, this is the case. Plus, spring and winter are getting shorter by about one minute per year and 30 seconds per year, respectively. Summer and autumn are getting longer by the same amounts.

Why is does it happen, and what does it mean for me? The main cause of this slippage of time over the centuries is a peculiar property of our spinning earth called “precession”. This physical trait of the world is analogous to a toy top that spins and wobbles. The wobbling of the top as it spins is precession. Regarding the earth, it is caused by both gravitation and the fact that our planet is not a perfect sphere. The earth is noticeably flattened compared to a perfectly round sphere. It is farther around the equator than around the poles. At the same time, earth is tilted about 23 ½ degrees to its orbit around the sun. That is what drives our seasons. When the earth’s northern hemisphere is pointed toward the sun in the summer, the sun’s gravity is slightly stronger in the north pulling it toward the sun. In the winter, when the southern hemisphere is aimed at the sun, the south is being tugged at a bit more. This produces a torque on the earth which leads to our precession. There is a similar effect from the moon applied against the earth. If our world was perfectly round, there would be no precession.

In the end, all of these exotic forces produce a slow movement of the earth’s North Pole against the backdrop of stars. This “precession of the equinoxes” amounts to about 50 seconds of arc per year and 20 minutes of time difference per year. The North Pole recycles to the same point in space every 25,765 years. During the early part of the last millennium, spring began on March 25th. And while many may remember the “usual” first day of spring being March 21st, here in the Pacific time zone the last time that actually happened was in 1963. From here on all first days of spring will either be on the 20th or the 19th. The next occurrence of a vernal equinox coming on March 21st will be in the year 2203. Due to precession, the trend will be to earlier and earlier springs.

How does this affect me? Considering none of us will live long enough to appreciate these geological time scale changes, probably not at all. It is more likely the application of Daylight Saving Time is having a much more profound influence than anything else. Celestial navigation would be impacted by the fact that Polaris, the North Star, no longer would occupy that spot in the sky due to precession. But who uses a sextant, especially with the advent of GPS satellites? Who is even aware of the grand movements of our celestial dome? They are so subtle. One thing we can all agree on is that spring is here, the birds and bees are doing their thing and once again nature has recycled itself with a fresh new beginning. That is how I know that everyone deserves a second chance. If it works in nature, it most certainly applies to all of us.