Bright Nights, Big Problems
Astronomers rate the darkness of our skies on a range of 9 (brightest) to 1 (darkest), and most of us spend our lives in the light of levels 5 to 8. All over the globe our nights are growing brighter, and almost nowhere are they growing darker. Studies increasingly link our overuse of light at night with health concerns such as sleep disorders and diseases. Other studies report the damaging ecological consequences and the big waste of energy. But the steady loss of darkness from our lives is not easily measured, for the true value of darkness is something we are barely aware of.
Since the beginning of time, a sky with stars was part of the common human experience. Everywhere on Earth, on most nights, people came face to face with the universe. This experience influenced their beliefs—their very understanding of their place in the world. Today, many of us live under skies which are polluted by light. We live under a night sky showing much fewer stars. Although our night sky continues to shape us, it is the absence of the universe around us that influences our beliefs to create. We are being shaped by a less experience of darkness, and most of us don't even know what we are missing.
Our Milky Way galaxy is home to several hundred billion stars, and the universe home to several hundred billion other galaxies. A sky with a large number of stars encourages us to emphasize our importance, to imagine humanity as the center of all things. Face to face with the endless size of the universe, we have the chance to know how insignificant we really are. But we also realize the true largeness of our living on this planet, and realize that we have an enormous responsibility to care, that there is no other place to go, that home is here.
"Everyone needs beauty as well as bread," wrote John Muir, American naturalist. Lighting designers understand that without darkness, there is no "city of light", and they work constantly to create their city's atmospheric beauty by mixing artificial light with darkness. And with night's moonlit geographies, its smells of desert rain and autumn fires, its insect symphonies interrupted by a bird's call on a lake, natural darkness has many offerings of its own.
Yet we are completely involved in artificial light. Much of this lighting is wholly unnecessary, born of habit and lack of awareness. So let us become aware: simply by keeping our existing lights we could significantly reduce their negative effects on our body, our mind, our soul. Artificial light at night is a wonder, a quality that enriches our lives. But the same has always been true of darkness, and can be again.
