1.Young's Double-Slit Experiment: 杨氏双缝实验
Thomas Young (1773-1829), an English scientist, conducted an experiment in 1801, known as Young's double-slitexperiment, that allowed him to show the wave nature of light and measure its wavelengths. The setup of this experiment is quite elegant--Light from a single source shines through two narrow, closely-placed slits for them to serve as two coherent light sources. (A coherent light source is one that makes light waveshave a consistent phase relationship with each other--crest overlaps crest,trough overlaps trough) A screen is put behind these slits.
托马斯·杨(1773-1829)，一位英国科学家，在 1801 年进行了一个实验，就是著名的“杨氏双缝实验”，这一实验使得他向人们展示了光的波动特性，并且可以测量波长。这个实验的安装十分讲究——来自同一光源的光将两条狭窄、挨得很近的裂缝照亮，那么它们就象两个相干光源（相干光源是指能够使得两束光相互有固定的位相关系，波峰与波峰重叠，波谷与波谷重叠）。
conduct vt. 处理；经营；引导；实施
elegant adj. 优雅的, 风雅的, 雅致的, 文雅的, 有风度的；优美的, 精彩的, 讲究的
crest 【物】波峰; 振幅; 峰值, 最大值
trough 【物】波谷
Now, if light consisted of particles, then the screen would reveal two bright lines when the light illuminatedthrough. Young, however, saw a center bright line and groups of symmetrical 对称的 darkand bright edges and explained these groups to be marks of constructive and destructiveinterference.
那么，若光由粒子组成，当光通过狭缝时，在屏幕上将显示两条明亮的线。不过，（托马斯·）杨看见中心是亮线，然后两侧是对称的明暗边缘，并且解释这些条纹就标志着相长干涉和相消干涉。
constructive interference 相长干涉（当两列同相的波相遇，它们的波峰／波谷会叠加成一个更大的波峰／波谷，这现象称为相长干涉。）
destructive interference 相消干涉（当两列反相的波相遇，一列波的波峰会叠加在另一列波
的波谷上，使两个波互相抵消，这现象称为相消干涉。）
2.Fresnel and Transverse Waves:菲涅耳和横电波
Augustin Fresnel, in 1821 put forward results from experiments involving double refraction and polarized light suggested that light is atransverse wave, which is a wave where the vibrating part moves perpendicularly to the coming wave. Equations that he formulated, the Fresnel equations provide the amplitude of reflected and transmitted polarized light traveling at a plane interface.
奥古斯丁·菲涅耳，在 1821 根据双折射和偏振光方面的实验提出结论，认为光是一个横波，所谓横波是指波的振动方向与传播方向垂直（原文：波的振动部分垂直地移向来波）。他推导出的方程式称为菲涅耳方程式，当光遇到一个平面的分界面时，它可以给出反射光和透射偏振光的振幅。
Transverse adj. 横向的, 横断的
formulate vt. 用公式表示, 明确地表达, 作简洁陈述；v. 阐明
amplituden. 【物】振幅
interfacen. 分界面
3.James Clerk Maxwell:
James Clerk Maxwell, a scientist studying electricity and magnetism, formulated the four Maxwell equations, which gave a predicted speed ofan electromagnetic wave through ether, which actually ended up being the speed of light, c. So from this point on, light was considered to be a part of the electromagnetic spectrum.
詹姆斯·克拉克·麦克斯韦，一位研究电学和磁学（电磁学）方面的科学家，总结出 4 个麦克斯韦方程式，这一方程组可以给出电磁波在以太中的预测速度，这实际上是给出了光速 c。因此自此以后，光被认为是电磁波谱的一部分。
Predict v. 预知, 预言, 预报, 预测
end up v. 竖着, 结束, 死
And later still, Einstein's theory ofrelatively helped throw out the idea of ether, which solved some problems dealing with the transversevibrations of waves in liquids and gases.
并且直至后来，爱因斯坦的相对论帮助（我们）丢弃以太的概念，这就可以解决在液体和气体中横波遭遇的一些（无法解决的）问题。
throw out v. 伸出, 扔掉, 说出, 派出, 放出, 使出局, 使突出, 显示
4.Geometrical Optics 几何光学
Let's face it. Optics is pretty complicated. Light travels in waves, and waves are not easy to analyze.That's why in this lesson we are going totry to explain as many phenomena of reflection and refraction as possible with only straight lines an dangles instead of waves to represent light.
让我们面对它。光学相当错综复杂。光以波的形式传播，而波也不容易分析。那也就是为什么在这门课中，我们将尽可能多地只用直线和角度而非波来描述反射和折射现象。
5.Wave Fronts and Rays 波前和光线
Waves, whether it is electromagnetic or other, are conveniently described in terms of wavefronts. A wavefront is the line or surface defined by adjacent portions of a wave that are in phase. --If an arc is drawn along one of the crests of a circularwater wave moving out from a point source, all the particles on the line will be in phase.
波，不论它是电磁的还是其它的，通常用波前来描述。波前是指一个波邻近部分的线或面，它们是同相的。如果一个光弧是沿着一个由点光源发出的圆形水波的振幅勾勒而成的，那么圆弧线上的所有点将是同相位的。
wave front 波前, 波阵面
in phase 【物】同相的[地]；同时协调的[地]
draw vt. 拉, 拖, 拉[拖]长, 拉成(丝等);
6.Reflection and Refraction 反射和折射
For the most part, we are still goingto talk about light in terms of straight lines and rays in this lesson,but to explain the concept of reflection,we will need to talk a little bit about the electromagnetic waves that compose light.
在绝大部分场合，我们将继续以直线和射线的方式谈论光，但是为了解释反射的概念，我们将需要探讨一点儿光用电磁波谱描述的情形。
The two most important methods of light propagation are reflection and refraction. Reflection involves the absorption and re-emission of light by means of complex electromagnetic in the atoms of the reflecting medium. Refraction refers to the change in direction of a wave at a boundary where the wave passes from one medium into another.
光的两种最重要传播方式是反射和折射。反射包含光的吸收和在反射介质的原子中光以电磁波动的形式重新发射光的两种情形。折射是指当光从一种介质进入另外一种介质时，在其界面处波从一种介质波传播方向发生变化的情形。
希望流星保佑光宝和大家，本月好运连连，倍儿顺！！！
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