Summer Solstice

Sunday, June 21st is officially the first day of summer, also known as the summer solstice. But what exactly is the summer solstice and why does the season change?
A common misconception about the summer solstice is that it represents the day when the earth is closest to the sun. The reverse is actually true. In January the earth is about 3 million miles closer to the sun than during summer. The solstice is instead caused by the tilt of the earth's axis.
The earth spins on its axis, which is tilted 23.5 degrees. If it weren't for that tilt, there would be no seasons. Would life even be possible?
From the winter solstice (in the northern hemisphere) on, the earth gradually tilts as it moves through its elliptical orbit around the sun. On or around June 21st, the northern hemisphere is tilted most towards the sun, thus receiving more hours of direct sunlight.
Another misconception about the summer solstice is that it is the day when the sun rises the earliest and sets the latest. This is not necessarily so. Though it is the day when there is the longest duration of sunlight, it is possible that the sun could still rise earlier (by a minute or so) after the date. The sun could also set a minute or two later.
On the day of the solstice, those areas north of the Arctic Circle receive 24 hours of sunlight. At the same time, areas south of the Antarctic Circle are in the dark for a full 24 hours. That must make for some pretty depressed penguins!
The word solstice is derived from the Latin sol (sun) and sistere (to stand still). Every day approaching the solstice the sun rises higher in the sky at noon. On the day of the solstice, the sun's movement is imperceptible from the day before. It seems to pause for one day on its cyclical journey through the heavens.
Even today it's hard not to feel some sense of awe, no matter how slight, about the solstices. It is amazing to think that the same thing has been occurring for billions of years.
Our ancestors were very much aware of the movements of the sun and moon - much more aware than we are today. For instance, one need only be reminded of the megalithic structure known as Stonehenge to realize that the ancients were very concerned with the movements of the heavenly bodies.
This mysterious structure is exactly aligned to both the sunrises and sunsets of the summer and winter solstices. What significance the ancient peoples found in this, we can only guess. But the solstices were obviously very important to these Bronze Age people. There are similar structures throughout the British Isles. In Ireland the megalithic site referred to as Newgrange is a huge circular stone structure, more than 5,000 years old (that predates both Stonehenge and the Great Pyramids of Egypt). At dawn of the winter solstice, a shaft of sunlight penetrates deep into the central chamber.
How were these "primitive" people able to construct such huge monuments aligned precisely with the sunrises and sunsets of the solstices without the use of complicated mathematical formulas? Simply by observing. They may not have known what an axis was, but just by watching the motions of the sun and the moon across the sky, they were able to pinpoint the exact moments of the sunset and the sunrise. By doing so they were able to form a calendar, integral to their agricultural life. There is some evidence that Stonehenge may have been used to predict solar and lunar eclipses as well.
It's also no coincidence that Canada's Aboriginal Day falls on June 21st. Ancient aboriginal cultures across North and South America also found great significance in the solstices. Around the time of the summer solstice, many nations in the Plains regions of North America celebrated Sun Dances.
Across the world the sun is associated with life and the growing of crops, thus agricultural symbolism is prevalent in most solstice celebrations. The ancient Celts of Britain and France often lit bonfires, as fire was a symbol of the sun. One of the traditions was leaping over the fire. The higher the flames, the taller the crops would grow, or so it was believed.
Interestingly, in many parts of the world, the summer solstice was considered the middle of summer rather than the beginning of it. To this day the summer solstice is called Midsummer in many European countries. This is mostly due to the fact that crops are already well advanced by late June in these parts of the world.
Solstice celebrations were celebrated by nearly every culture. The Christian church tried to get rid of these pagan ceremonies, and replaced summer solstice festivities with St. John the Baptist Day on June 24th. It is also hardly coincidental that the most important Christian holiday of the year, Christmas, falls so close to the winter solstice. However, the solstices themselves were still important to Christians. Medieval churches often contained an oculus, or hole in the ceiling which allowed a shaft of sunlight to shine down. The sunlight followed a path on the floor, and when it reached a certain point, the solstices could be figured out. In this way church officials were able to set the dates for Easter and other important Christian events.
For us, though, summer officially begins at 11:46 pm, June 20th. On June 21st, the first full day of summer, the sun will rise at 4:47 am and set at 9:13 pm, giving us 16 hours and 26 minutes of sunlight.