illuminance
ih-LOO-mih-nuhns
Definition
A measurement of the total amount of light that hits or passes through a specific surface area, often used to gauge how much light is reaching a person's eyes.
Etymology
Derived from the Latin word 'illuminare,' meaning to light up or brighten, which is formed by the prefix 'in-' (into) and 'lumen' (light). It entered English in the late 19th century as a technical term for the intensity of light falling on a surface.
In the news
The article uses this term when discussing the scientific measurement of light's intensity, specifically introducing the concept of melanopic equivalent daylight illuminance to better describe how light affects our biological clock compared to standard lux measurements.
Morning sunlight can reset the body clock surprisingly quickly because outdoor light is vastly brighter than most indoor environments — but the popular five-minute rule isn't a proven biological threshold, and window glass weakens the signal rather than blocki
Read the full article ↗ScienceBlog.com