Higher levels of exposure to artificial light at night were linked to increased stress-related activity in the brain, inflamed arteries and a higher risk of heart disease, according to a small study of adults in Boston. Nighttime light pollution appeared ...

A light-year is how astronomers measure distance in space. It’s defined by how far a beam of light travels in one year – a distance of six trillion miles. Think of it as the bigger, badder cousin of the inch, the mile, the kilometer, and the furlong.

Light therapy can be defined as exposure to daylight or specific wavelengths of light for a prescribed amount of time in order to treat seasonal affective disorder, acne, and a myriad of other conditions. Even though this type of treatment is generally ...

Kaiwei Tang helped create the iconic Motorola Razr over 20 years ago. Now, 10 years into building Light, the startup behind the minimalist smartphone alternative Light Phone, he’s as surprised as anyone that his customers are begging for a flip phone.

Light therapy is an alternative treatment method for dry eyes. It works by treating meibomian gland dysfunction, one of the most common causes of dry eye. When first-line treatments — such as eye drops — do not work, a doctor may recommend intense ...

It is International Dark Sky Week, an annual event when stargazers around the world raise awareness of our diminishing night sky. In many bustling cities and towns, bright lights from towering high-rise buildings, houses and street lamps obscure views of ...

EDITOR’S NOTE: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex’s Perpetual Planet Initiative has partnered with CNN to drive awareness and education ...

Why isn’t the universe overflowing with light? The question might seem naive at first glance, but it isn’t. If space is jam-packed with stars, why isn’t it flooded with light? This is the heart of Olbers’ Paradox.