Which term refers to light that is directed or reflected upward and wasted?

The term that refers to light that is directed or reflected upward and wasted is "sky glow." This phenomenon occurs when artificial light is emitted into the atmosphere, causing a glow that obscures the visibility of stars and natural celestial events. Sky glow is not only a waste of energy but also contributes to light pollution, which can impact both wildlife and human health. It highlights the importance of designing lighting systems that minimize upward light output and focus illumination where it is needed, thereby making lighting more efficient and sustainable.

In contrast, the other terms have different meanings: trespass refers to an unauthorized entry or infringement, glare pertains to excessive brightness that can cause discomfort or impair vision, and direct lighting describes lighting that is aimed straight at a surface without scattering. Understanding the distinctions among these concepts helps in effectively managing lighting in sport facilities to improve both visibility and sustainability.