The first light-emitting diode (LED) was created in 1927, but LED technology wasn’t mass-marketed or mass-produced until the 1990’s.
Lighting is the application of energy technology to create practical or atheistic artificial light.
Exposure to light in moderation, especially natural sunlight, can have an uplifting effect on mood, while excessive darkness can have the opposite effect.
Competitive sports became popular in the United States from 1850 – 1950 because of lighting technology, mass media, and developing labor and education laws.
Artificial light changed sleeping habits. People used to sleep in two phases, “first sleep” and “second sleep”, with two hours of awake time between.