Monday, December 9, 2013
By BERNIE REIM
The month of June always marks the beginning of summer for us in the northern hemisphere. This year that will happen at 1:04 a.m., June 21. The word solstice means "sun stands still" in Latin.
That day marks the farthest north of east that the sun will rise and the farthest north of west that the sun will set for the whole year. It is exactly the opposite in the southern hemisphere, where the sun rises farthest south of east and sets farthest south of west, marking the first day of winter.
You can actually prove this for yourself as you figure out exactly where the sun stands still as part of your everyday landscape. Just pick a fixed place from which to watch. It could be a stone to sit on with a good western view, a mark on the ground, or a high, west-facing window. Starting several weeks before the solstice, watch the sun going down and sketch and mark the points near the horizon, trees, buildings or mountains.
Mark and date on your sketch exactly where the sun sets each evening. As you approach the solstice, you will notice that the difference each night will get less and less. Keep going until a week or so beyond the solstice when the sun starts moving south again. It will be easier to track this as the sun speeds up again going south and the difference gets greater each day. Then look halfway between the dates that you marked when the sun was moving north and the equal amount of time when the sun was moving south again, and that will be the summer solstice.
That may be very similar to the way the people who built Stonehenge about 5,000 years ago figured this out for themselves. Stonehenge is a wonderful, permanent marker to track the change of the seasons and probably also a great tool with which to calculate eclipses. There are tours that will allow you to go inside the circle during the solstices.
It is interesting to think that the very second we pass the summer solstice, the days are getting shorter again and we will already be on our way to the winter solstice in six short months.
You can also prove another aspect of the solstice by showing that the shadows are at their shortest for the year and point true north at local apparent noon near the summer solstice. Find the actual clock time for this moment using a planetarium program. Put a stick or rod in the ground and mark where the tip of the shadow falls at that moment. You will notice that the shadow will shrink as the summer solstice gets closer, hold still for several days, then lengthen again at a faster rate.
These little exercises will not only connect you with your ancient ancestors and help you appreciate how they figured all this out without satellites and computers and Google Earth, but it will also help you to tune in to your natural surroundings in a more detailed way.
It will make you much more aware of the continuing change of the seasons, and help you relate to the constantly changing positions of the earth and the sun and what effects these changes produce. It should also help you look beyond all these seasonal changes, and find the constant and unchanging aspects of life that go far deeper than the surface seasonal changes.
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