light ray

Andrew Strominger of Harvard discovered that, when viewed from the right mathematical perspective — that of a light ray headed toward the infinite future — black holes are more complicated than we thought.

A ray of light normally travels in a straight line through empty space, but if the ray passes close by a massive object, the curve in space created by the star acts like a bend in the road, causing the light ray to veer away from its formerly straight path. 

The current industry-standard chip-making machine produces a light ray that draws 38-nanometer-wide lines.

A light ray bouncing off an object usually travels in a straight line to your eye.

When a light ray traveling through air enters such a material, it changes direction, creating a sort of kink.