Everything You Need to Know About Blue Light

Photo Courtesy: Marvel Studios/The Walt Disney Studios/IMDb

For beach-goers, experts always recommend a healthy coating of sunscreen to protect the skin from those pesky ultraviolet (UV) rays. But sunlight contains more than just UV light. In fact, it’s made up of red, green, yellow, blue and orange light rays, which combine to create "white light" (a.k.a. sunlight). If you haven’t sat through a high school chemistry class in a while, no worries. We’ll break down the important stuff — without getting too scientific.

As the name suggests, visible light can be seen by the human eye, and each ray reflects a particular color. The color of a given ray depends on said ray’s wavelength (see the graphic below) — or the distance between successive crests of a wave. (Side note: This means that objects get their colors through the wavelength of the light that is reflected from them. Trust us — don’t think too hard about it. Things get trippy.)

Another important relationship to note is that of wavelengths and energy: The longer the distance between waves, the less energy a ray has to offer. Think of it this way — if the wave crests are farther apart, they’re a bit lackadaisical, but if the crests come in rapid succession, there’s a frenzy of energy there. All of this means rays on the red end of the visible light spectrum have longer wavelengths and less energy, whereas rays on the blue end have shorter wavelengths and more energy.

UV rays, which aren’t on the visible light spectrum, surpass blue light in terms of how much energy they contain. That incredible amount of energy is how those rays are able to create a physical change, like tanning (or burning) one’s skin. In moderation ultraviolet radiation can be good for us (think vitamin D!), but, on the other hand, it can also produce some devastating effects (think sunburn and snow blindness!).