Level 5 - Unit 2 - Part 2 Listen

People have wondered about the nature of light and color since ancient times. Some people though that light came from the eye rather than coming into the eye. To see, light was projected from our eyes to illuminate things as we look at them. Now we know that what we see is mostly reflected light, like the light from the moon which is reflected sunlight. Light comes from a light source, such as the Sun, and either enters our eyes directly or after it has reflected off something.
很久以前，人们就对光和色的本质产生了疑问。有些人认为光来自眼睛而不是进入眼睛。当我们看东西时，为了看见光就会从我们的眼睛投射出来照亮它们。现在我们知道我们看到的大部分光的反射，就像月球的光就是来自太阳光的反射。光来自光源，比如太阳，它要么直接进入我们的眼睛，要么经物体反射之后进入。

In 1666 Sir Isaac Newton showed that when light passes through a prism, it separates into all the other colors. This clearly demonstrated that light is composed of many different colors. The difference between colors is due to their wavelength. A prism separates light into different colors because each color has a different wavelength. The angle at which a color bends in a prism depends on its wavelength.
1666年，艾萨克·牛顿爵士指出，当光穿过棱镜时，它会分解成所有其他颜色。很明显这证明光是由很多不同的颜色组成，颜色之间的差异取决于它们的波长。棱镜把光分解成不同的颜色，因为每种颜色的波长不同。颜色在棱镜中弯曲的角度取决于其波长。

Colors with shorter wavelengths bend more than colors with longer wavelengths. This explains why red light bends less than yellow light. The reason is because its wavelength is longer. Of the visible colors, voilet light has the shortest wavelength, so it bends the most.
波长较短的颜色比波长较长的颜色容易弯曲。这就解释了为什么红色光弯曲度小于黄色光，因为红色光的波长更长。在可见的颜色中，蓝紫光的波长最短，所以弯曲度最大。

If you have ever painted, you know that different colors can be combined to create new colors. For example, if you add white to a color, you lighten it. However, the three primary colors, red, blue and yellow cannot be made by mixing other colors. It isn't possible to mix any combination of colors to create red, blue or yellow. Mixing two primary colors creates a secondary color such as purple, which is made by mixing blue and red. Mixing three primary colors creates a tertiary color such as brown or gray.
如果你画过画，你就会知道不同的颜色可以组合成新的颜色。例如，如果你给一种颜色加上白色，它就会变亮。不过，红蓝黄三原色不能通过混合其他颜色来得到。不可能混合任何颜色的组合来创建红色、蓝色或黄色。混合两种原色会产生二次色，比如紫色，由蓝色和红色混合而成。混合三种原色会产生三次色，比如棕色或灰色。