Light and colours: an interaction between daylight and artificial light

Often a dichotomy between daylight and artificial light is observed, often artificial lighting replaces daylight. In Denmark daylight is characterized partly by being "borrowed" half of the year, partly by having long transitions periods between the light and the dark (nautical and civil twilight). For these reasons artificial lighting does not complement daylight but provides, coupled with the daylight, the total lighting in the indoor environment. Electric lighting is therefore ‐ in a complex interaction with the daylight ‐ of great importance for both our lighting and our wellbeing. Studying artificial lighting without studying daylight seem to be a common procedure of the practice of today in Denmark and other parts of the industrialized world. As a consequence of this artificial lighting suffers from a quantifying tyranny, a tyranny where the quality of light is measured in quantities. This procedure does not provide a good and sustainable support in the future for the human vision and wellbeing.