Although many people were skeptical and hesitant to adopt newfangled lighting devices, they soon discovered that gas was less expensive and more convenient than candles and oil lamps. By the 1870's it was widespread in British and American urban centers, but gas lighting was destined to be short lived. The electric light bulb, perfected by American Thomas Alva Edison and Joseph Swan of Great Britain in 1879, began a new era of interior lighting. At first the rivalry between gas and electric light companies was fierce because they were vying for control of the market, but the superiority of electric light became evident. Although in the modern era we depend on artificial light a great deal, we've also renewed our appreciation and understanding of natural light.
Current research shows that the sun and moon impact our health.
Light has a profound effect on our body chemicals that dictate the way we feel, sleep, eat, and behave. Thus, during the normal course of a day, the changes in daylight will cause these chemicals to fluctuate, which alters our mental and physical well-being. The changes can be most apparent on a seasonal basis. During the winter months when the days become shorter, body chemicals shift and cause mood, energy, and sleep changes, as well as susceptibility to illnesses and disease. Medical scientists are learning how to use natural and artifical light to influence our well-being, enliven our spirits and lighten our moods.