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

使透的折射和使单面的反射。

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.

那些不反射的望远的是折射。他们有透系统。透系统的想法最早是伽略来观测星星的。

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，拉丁文写作的牛顿选择英文写他的《光学》，在这个过程中引入了透、折射等词。

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.

由于两侧的焦距相同， 我们从蜡烛顶部绘制第二条光线， 通过 F 主焦点，然后通过透折射并平行于轴传播。