Certain types of light have proven to be an effective, minimally invasive treatment for cancers located on or near the skin when combined with a light-activated drug. But deep-seated cancers have been ...

The universe's expansion means its size is bigger than its age suggests. The universe's expansion doesn't have a speed limit like objects within it. Distant galaxies move away from us as space itself ...

Black holes can’t be formed from pure light. Quantum physics would curb their creation under any foreseeable conditions, a new study suggests. Typically, matter is responsible for black holes. They’re ...

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their ...

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 ...

FEW PEOPLE enjoy the gloom that comes with winter in the world’s higher latitudes. In up to a tenth of the population, the long nights can trigger a type of depression known as seasonal affective ...