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  • 反射反射

    A dancer in a red outfit practicing in front of a mirror, observing her reflection.

    This dancer is practicing in front of a mirror so she can see how she looks as she  performs. She's  watching her image in the mirror as she  dances. What is an image, and how does it get “inside” a mirror? In this article, you’ll find out.  
    ::这名舞者在镜子前练习,这样她就能看到她表演的样子。她在跳舞时在镜子里看着她的形象。什么是图像,它怎么会得到镜子呢?在这篇文章中,你会发现。

    Reflected Light and Images
    ::反射光和图像

    Reflection is one of several ways that light can interact with matter. Light reflects off surfaces such as that do not transmit or absorb light. When light is reflected from a smooth surface, it may form an image. An image is a copy of an object that is formed by reflected (or refracted) light.
    ::反射是光能与物质互动的几种方式之一。 光反射会反射出表面, 如不传输或吸收光的表面。 当光从光滑的表面反射时, 光会形成图像。 图像是由反射( 或反相) 光组成的物体的复制件 。

    Q: Is an image an actual object? If not, what is it?
    ::问题:图像是真实对象吗?如果不是,那是什么?

    A: No, an image isn’t an actual object. It is focused rays of light that make a copy of an object, like a picture projected on a screen.
    ::A: 不, 图像不是一个实际对象。 它是一个聚焦光线, 复制一个对象, 就像屏幕上投射的图片一样 。

    Regular and Diffuse Reflection
    ::经常反射和分辨反射

    If a surface is extremely smooth, as it is in a mirror, then the image formed by reflection is sharp and clear. This is called regular reflection (also called specular reflection). However, if the surface is even slightly rough or bumpy, an image may not form, or if there is an image, it is blurry or fuzzy. This is called diffuse reflection.
    ::如果表面像镜子一样极光滑,那么反射形成的图像是清晰清晰的。这称为定期反射(也称为光镜反射 ) 。 但是,如果表面甚至略微粗糙或模糊,则图像可能不会形成,或者如果有图像,则模糊或模糊。 这被称为散射反射 。

    Q: Look at the boats and their images in the Figure . Which one represents regular reflection, and which one represents diffuse reflection?
    ::问题:看看图中的船只及其图像。哪个代表定期反射,哪个代表分散反射?

    A: Reflection of the boat on the left is regular reflection. The water is smooth and the image is sharp and clear. Reflection of the boat on the right is diffuse reflection. The water has ripples and the image is blurry and wavy.
    ::A: 左边船只的反射是定期反射。 水是光滑的, 图像是清晰的。 右边船只的反射是分散的反射。 水有波纹, 图像是模糊的, 模糊的。

    Two boats reflecting on water: left shows clear reflection (regular); right shows blurry (diffuse).

    In the Figure , you can see how both types of reflection occur. Waves of light are represented by arrows called rays. Rays that strike the surface are referred to as incident rays, and rays that reflect off the surface are known as reflected rays. In regular reflection, all the rays are reflected in the same direction. This explains why regular reflection forms a clear image. In diffuse reflection, the rays are reflected in many different directions. This is why diffuse reflection forms, at best, a blurry image. 
    ::在图中,您可以看到两种反射类型是如何发生的。光波由被称为射线的箭来代表。撞击表面的射线被称为事件射线,反射表面的射线被称为反射射线。在定期反射中,所有射线都反映在同一方向。这解释了为什么定期反射形成清晰的图像。在扩散反射中,射线反映在许多不同的方向。这就是为什么扩散反射图像充其量只是模糊的图像。

    Regular and diffuse reflection of light rays.

    Law of Reflection
    ::反思法

    One thing is true of both regular and diffuse reflection. The angle at which the reflected rays leave the surface is equal to the angle at which the incident rays strike the surface. This is known as the law of reflection . The law is illustrated in the Figure .
    ::常规反射和散射反射都是这样。反射射线离开表面的角与事件射线撞击表面的角相等。这被称为反射法则。图中说明了法律。

    The law of reflection with angles of incidence and reflection.

    According to the law of reflection, the angle of reflection always equals the angle of incidence. The angles of both reflected and incident light are measured relative to an imaginary line, called normal, that is perpendicular (at right angles) to the reflective surface.
    ::根据反射法则,反射角度总是与事件角度相等,反射角度与反射角度相同,反射角度和事件光角度都比想象的直线(正常线,即垂直(右角)与反射表面)测量。

     Watch this video to learn more about reflection:
    ::观看这段影片以了解更多反思:

    Summary
    ::摘要

    • Reflection is one of several ways that light can interact with matter. When light is reflected from a smooth surface, it may form an image. An image is a copy of an object that is formed by reflected (or refracted) light.
      ::反射是光能与物质互动的几种方式之一。 当光从光滑的表面反射时, 光可以形成图像。 图像是由反射( 或反相) 光组成的对象的复制件 。
    • Regular reflection occurs when light reflects off a very smooth surface and forms a clear image. Diffuse reflection occurs when light reflects off a rough surface and forms a blurry image or no image at all.
      ::当光从非常光滑的表面反射出来并形成清晰的图像时,即为正常反射。 当光从粗糙的表面反射出来并形成模糊的图像或根本没有图像时,即为模糊反射。
    • According to the law of reflection, the angle at which light rays reflect off a surface is equal to the angle at which the incident rays strike the surface.
      ::根据反射法则,光线从表面反射的角度等于事件射线撞击表面的角度。

    Review
    ::回顾

    1. What is an image?
      ::什么是图像?
    2. Identify the object and the image in the Figure . Which type of reflection formed the image: regular reflection or diffuse reflection? How do you know?
      ::在图中标出对象和图像。哪类反射构成图像:定期反射还是分散反射? 你怎么知道?

    A reflection of an object on water's surface, showing clear distinct features.

    1. What is the law of reflection?
      ::什么是反省法则?
    2. Label the angle of incidence and the angle of reflection in the Figure .
      ::图中标出事件角度和反射角度。

    Diagram depicting the law of reflection with angles of incidence and reflection labeled.