(noun; adjective. /uhl-tra-VAI-let)
by Nicole Gadda
What does it mean?
Ultraviolet (more commonly referred to as UV) light is a form of electromagnetic radiation (or, in other words, light). Ultraviolet light has a wavelength from 10 nanometers to 400 nanometers. In physics, a wave can be thought of as a disturbance that travels through space and time, accompanied by a transfer of energy. When we talk about wavelength, we’re referring to the distance over which the wave repeats.
All forms of light travel as waves, including the light that our eyes see as colors. Ultraviolet light has a wavelength that’s shorter than the violet end of the spectrum of visible light, meaning we can’t physically see UV rays.
UV radiation is present in sunlight and is what causes the sunburn you get after a long day laying out at the beach. UV light can also damage DNA and sterilize surfaces, water, and the air. Most of the UV radiation present in sunlight is filtered out by the atmosphere, which is why life on Earth can thrive despite the presence of ultraviolet rays from the sun. In fact, while too much exposure to UV can cause sunburns and increase our risk of skin cancer, a small amount of UV light is necessary for humans to obtain vitamin D — an essential nutrient for our survival.
How do I use it in a sentence?
The ultraviolet radiation from the sun on a bright day in North Carolina will surely give me a sunburn if I forget to apply my sunscreen.
Etymology
“Ultraviolet” was coined in 1840, from “ultra” = beyond + violet, to mean “beyond the violet end of the visible spectrum.”
Related terms
Radiation, electromagnetism, infrared, wavelength, light spectrum
Fields of study in which this word is commonly used
Physics
Biology
Meteorology
