6/21/2010

Summer Solstice Science

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The Summer Solstice is the day of the year in which we have the longest period of daylight. Today in Tampa the sun rose at 6:34am and will not set until 8:29pm.

The Summer Solstice occurs exactly when the Earth's axial tilt or obliquity is most inclined towards the sun at its maximum of 23° 26'. In the Northern Hemisphere this generally happens at a point between June 20th and June 21st when the Northern Hemisphere is tilted closest to the sun. In the Southern Hemisphere this is reversed. Today the Southern Hemisphere is tilted furthest away from the sun and is currently experiencing the Winter Solstice or longest period of night. In the Southern Hemisphere the Summer Solstice occurs in late December. The cumulative cooling and warming that result from the tilt of the planet become most pronounced after the solstices, leading to the custom of using these days to mark the traditional beginning of summer and winter.

Since Neolithic times, cultures have celebrated the longest days and nights of each year. In Roman times the Summer Solstice was celebrated each summer on June 24th. In fact, the word solstice derives from the Latin words sol (sun) and sistere (to stand still). In ancient Europe pagans lit great bonfires on the night of the Sunchoke Summer Solstice and the holiday was often connected with healing and the first fruits of the seasons. With the advent of Christianity the date of the solstice became connected with the birth of St. John the Baptist and is still celebrated as St. John’s Day in many countries.

Have a fantastic longest day of the year and a happy summer!