Sky glow refers to the brightening of the night sky that results from sources of artificial light. The /sk/ sound is spelled with the letters "s" and "k" which represent two different sounds in English. The /aɪ/ sound in "sky" is spelled with the letters "y" and "i", indicating a diphthong or a combination of two vowel sounds. The word "glow" is spelled phonetically with the /ɡl/ and /oʊ/ sounds represented by the letters "g" and "o". Together, the IPA phonetic transcription for "sky glow" is /skaɪ ɡloʊ/.
Sky glow refers to the atmospheric phenomenon characterized by the brightening of the nighttime sky caused by the reflection and scattering of artificial and natural light sources. It occurs predominantly in urban and densely populated areas due to the increasing prevalence of outdoor lighting. This excessive illumination creates a diffuse and hazy glow that obscures the natural darkness of the night sky.
Sky glow is primarily a result of light pollution, which occurs when artificial lights are not properly directed or shielded. The scattered light interacts with air molecules, dust particles, and other atmospheric constituents, leading to a diffusion of the light and an overall brightening effect on the sky. This diffusion reduces contrast and visibility of stars, planets, and other celestial objects, making it challenging for astronomers and stargazers to observe and study the night sky.
The consequences of sky glow extend beyond a mere aesthetic issue. Light pollution and sky glow have negative impacts on various aspects of human life and the environment. They disrupt ecosystems, disturbing migrating birds, nocturnal animals, and insects. Sky glow also affects human health, disrupting circadian rhythms and potentially causing sleep disorders. It is a waste of energy and contributes to the greenhouse gas emissions associated with electricity production for unnecessary lighting.
Efforts to combat sky glow include using shielded or fully cut-off fixtures, reducing outdoor lighting levels to only what is necessary, and implementing lighting ordinances and regulations to minimize light pollution. By minimizing sky glow, we can preserve the natural beauty of the night sky, protect wildlife, and reduce energy waste.
The term "sky glow" is a compound word consisting of "sky" and "glow".
The word "sky" originated from the Old Norse word "ský" meaning "cloud", which has cognates in other Germanic languages such as Old English "sceo" and German "Scheibe". Over time, the meaning of "sky" expanded to refer to the entire expanse of the atmosphere above the earth.
"Glow", on the other hand, comes from Middle English "glouen" which derives from Old English "glōwan" meaning "to glow, to shine". It has Germanic roots and is related to Dutch "gloeien" and German "glühen". The word "glow" generally refers to a soft, steady, and radiant light emitted by something that is heated.