Applied scotobiology in luminaire design

Abstract

Studies of our illuminated environment demonstrate the importance of light to humans, who by evolution are essentially daytime creatures. However, the study of behaviour and the biology that occurs during the night has clearly shown the importance of darkness for both humans and the ecological integrity of the countryside. Since humans are expanding their activity throughout the night and into rural areas, is there a compromise between the human desire for light and the need for darkness? All animals and plants have light thresholds to which they have evolved. We have applied the findings of scotobiology to determine outdoor lighting that minimizes the disruption of artificial light at night on the natural environment and on human health. It is not surprising that the key characteristics to be limited are the brightness, duration and extent of the emitted light, the amount of glare and the spectrum of the emitted light. To test the practicality of these limits, we present the patented design of a luminaire that bridges the desire for 24 × 7 human lifestyles and the protection of the nocturnal environment.