There are two main flavors of telescope: refractors, which use a lens, and reflectors, which use a mirror.

使透镜折镜和使单面镜镜。

Those telescopes that do not employ reflection use refraction. They have a system of lenses, an idea first used to look at the stars by Galileo.

那些不利望远镜利是折。他们有透镜系统。利透镜系统想法最早是伽利略来观测。

In 1704, Newton, having written in Latin until that time, chose to write his " Opticks" in English, introducing in the process such words as lens, refraction, etc.

1704年，一直拉丁文写作牛顿选择英文写他《光学》，在这个过程中引入了透镜、折等词。

Since the focal length is the same on both sides, we draw a second ray from the top of the candle, through the F prime focal point, which then refracts through the lens and travels parallel to the axis.

由于焦距两边相同， 我们从蜡烛顶部画出第二条光线， 穿过F'焦点，然后通过透镜折， 并沿轴平行传播。