Earth is a perfect planet. It has an atmosphere with the perfect mix of oxygen, nitrogen and other gases to sustain life. It has a moon to control the ocean tides. Most important, it has a big bright sun to give life to all the creatures below. In looking for life on other planets, having a sun is one of the essential components for the possibility to even exist.
Sunlight not only affects our lives; it gives us life. From being the heat source that keeps our planet from becoming a block of ice to making corn grow in Iowa, the sun is our life core. It provides the energy that causes photosynthesis in plants that in turn provide us with food, building materials, and oxygen that keeps our atmosphere in balance. Sunlight evaporates water from oceans, sending it into the atmosphere to be transformed into rain that falls as life-giving liquid on the dry land parts of Earth. Sunlight is an ingredient in diversity of life, promoting animals and plants to exist in every climate zone of the earth and seas. Sunlight grows plankton in the ocean, rubber trees in Brazil, and camellias in my back yard. The more sunlight we have, the longer our growing season. The longer our growing season, the more food and beauty the earth can produce.
Sunlight warms us. In a world concerned with global warming, it is important to study the effects of global cooling, a possible event which could end life. Sunlight provides energy. Modern technology is well on its path to turning more and more solar energy into power that will heat our homes, power our factories, and perhaps someday even run our cars. Solar-charged cells may be an important component in reducing the earth's dependence on fossil fuels.
Sunlight prevents disease. While the emphasis has been on avoiding the skin-damaging effects on too much sunlight, medical science is now beginning to understand the beneficial aspects of sunlight. It provides the all important Vitamin D which strengthens bones and prevents some cancers. People who live in sun rich areas of the world near the equator have much lower rates of breast and colon cancer and osteoporosis than those of us who don't receive as much sunlight. While it's still advisable to wear skin screen to guard against skin cancer, we are now being encouraged to allow the sun's health-giving rays to bathe our bodies at least some time every day.
Sunlight improves the happy endorphin and seratonin presence in the body. SAD, Seasonal Affective Disorder, is the mental depression that happens to some individuals deprived of sunlight in the winter. Up to a half million people in the U.S. suffer from winter depression related to shorter daylight hours. It is more common in women than men and increases in severity with age. To alleviate this lack, people do everything from sitting under sun lamps to vacationing in Arizona all to make their bodies feel normal and full of sunshine.
All of us have a desire to walk "on the sunny side of the street." It's why we put skylights in our homes, paint our kitchens yellow, and vacation in Hawaii. It's why humanity has worshipped sun gods and goddesses since the beginning of time. While we may no longer refer to the sun as God, its all-being importance is ever present in our lives. We go to bed at night, confident in the fact that come morning, the sun will rise, and we'll all be happy to join the Beatles in singing "Here Comes the Sun."