They have a system of lenses, an idea first used to look at the stars by Galileo.

他们有透镜统，利用透镜统的想法最早是伽利略用来观测星星的。

Say we have a lens that has a spherical face on both sides, known as a convex lens.

假设我们有一个具有球面的镜头 两侧，称为凸透镜。

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.

利用反射的望远镜利用的是折射。他们有透镜统。利用透镜统的想法最早是伽利略用来观测星星的。

Vieira said that the combined abilities of James Webb and gravitational lensing made it possible for the researchers to observe through the dust to identify the PAHs.

维埃拉说，·韦伯太空望远镜和引力透镜效应的结合能使研究人员有可能透过尘埃观察到多环芳香烃。

So, if you have a curved piece of glass, like a lens, it can focus lots of incoming rays of light into a small spot called a focal point.

所以，如果你有一块弯曲的玻璃，像透镜一样，它可以将大量入射光线聚焦到一个叫做焦点的小点上。

Although there have been many improvements made over the centuries, most big modern telescopes at their heart are based on the Newtonian design, and in fact no large professional-grade telescopes made today have a lens as their objective.

尽管几个世纪以来已经有了很多改进，但大多数大型现代望远镜的核心都是基于牛顿的设计，事实上，现在制造的大型专业级望远镜都使用透镜作为接物镜。

And although a second satellite containing the " eyepiece" (a special lens that also uses Fresnel optics, and a camera to record the image) must fly at the focus, the accuracy required is only hundredths of a metre, not billionths.

并且，尽管还必须有一个含有" 目镜" （也是一种运用菲涅尔视觉的特殊透镜，也是一种记录图像的相机）的卫星在焦点上运行，所需要的精准度也只是百分之一米。