This intense heat they project in a parallel beam against any object they choose, by means of a polished parabolic mirror of unknown composition, much as the mirror of a lighthouse projects a beam of light.

VOA: special.2010.09.01

It is an electron beam. In the 1890s, the latter part of the 19th century a very fashionable word was "ray."

那是个电子束，在十九世纪九十年代，就是19世纪末,一个很时髦的词汇-“光线“

麻省理工公开课 - 固态化学导论课程节选

So this gives you a little bit of an idea of just how many individual photons there are in a laser beam of light. This is a huge number of photons.

这个给你们一点思路关于,一个激光束有多少独立的光子,这是一个巨大的光子数目。

麻省理工公开课 - 化学原理课程节选

You have a single beam coming in, and you end up with rings.

单个光束进来，以光圈的形式出去。

麻省理工公开课 - 固态化学导论课程节选

And this is a very fast speed, of course, it's about 700 million miles per hour. So, one way to put that in perspective is to think about how long it takes for a light beam to get from earth to the moon. Does anyone have any guesses? Eight seconds, that sounds good.

当然这是一个非常快的速度，它大约是每小时7亿英里,为了更形象化，我们,看看光从地球到月球,需要多少时间，你们猜猜是多少？,8秒，猜的不错。

麻省理工公开课 - 化学原理课程节选