And one thing that Einstein put forth is he figured if well, what we're saying is that light is, in fact, a stream of particles, each one of those particles or photons must, therefore, have a momentum.

爱因斯坦提出了一件事情,他指出如果我们所说的光，事实上是一束粒子，那么这些粒子或者光子中的，每一个都有动量。

麻省理工公开课 - 化学原理课程节选

Feature photography: Javier Manzano, a free-lance photographer, for his extraordinary picture distributed by Agence France-Presse of two Syrian rebel soldiers tensely guarding their position as beams of light stream through bullet holes in a nearby metal wall.

WSJ: 2013 Pulitzer winners in journalism and arts

Better to have that piece of work done locally by all the endpoints and have them send a light information stream to the center: a single map coordinate rather than a bunch of tower coordinates and distance measurements.

FORBES: The Case For Endpoints

The move brings to light a separate stream of the family, derived from the affair of a great-grandfather and an African-American cook, and black and white relatives, hitherto unknown to one another, gather together.

NEWYORKER: Moving Midway