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  • General

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  • 地球上的太阳能

    Lesson
    ::经验教训

     

    Bright sunlight shining in a blue sky with trees silhouetted in the foreground.

     

    Just how important is this star?
    ::这颗星星有多重要?

    Almost all  energy  at Earth's surface comes from the  . The Sun’s energy heats the  planet  and the air around it. This causes the  atmosphere  to move and create  . Sunlight also powers  photosynthesis  and life on Earth.
    ::地球表面几乎所有的能量都来自太阳。太阳的能量使地球及其周围的空气发热。这导致大气移动和形成。阳光还赋予地球光合作用和生命力量。

    The Sun's Energy
    ::太阳的能量

    Most of the energy at Earth's surface comes from the Sun.   travels in tiny packets that move in waves. The waves have different  wavelengths . Waves with different wavelengths carry different amounts of energy.
    ::地球表面的能量大部分来自太阳。 以小包形式移动, 随波逐浪移动。 海浪的波长不同。 不同波长的波浪的能量不同。

    Photons of Energy
    ::能源光子

    The Sun gives off energy in tiny packets called  photons . Photons travel in waves. These waves make up  electromagnetic radiation . The image below models a wave of light ( Figure   ). Notice the wavelength in the figure. Waves with shorter wavelengths have more energy.
    ::太阳以小包的光子释放能量。 光子在波浪中流动。 这些波由电磁辐射组成。 下面的图象是光波( 图示 ) 。 注意图中的波长。 短波长的波浪有更大的能量 。

    Wave model showing crest, trough, and labeled wavelength of light.

     

    This curve models a wave. Based on this figure, how would you define wavelength?
    ::这个曲线模拟一个波。 根据这个数字, 您如何定义波长 ?

    Electromagnetic Spectrum
    ::电磁频谱

    Energy from the Sun has a wide range of wavelengths. The total range of energy is called the  electromagnetic spectrum  ( Figure   ).
    ::来自太阳的能量有多种波长,总能量范围称为电磁频谱(图)。

    Illustrates the electromagnetic spectrum, highlighting types of radiation from radio waves to gamma rays.

     

    Compare the wavelengths of radio waves and gamma rays. Which type of wave has more energy?
    ::比较无线电波和伽马射线的波长。 哪一种波的能量更多?

    Visible light  is the only light that humans can see. Different wavelengths of visible light appear as different colors.  Radio waves  have the longest wavelengths. They also have the least amount of energy.  Infrared light  has wavelengths too long for humans to see, but we can feel them as  heat . The atmosphere absorbs the infrared light.  Ultraviolet (UV) light  is in wavelengths too short for humans to see. The most energetic UV light is harmful to life. The atmosphere absorbs most of this UV light from the Sun.  Gamma rays  have the highest energy, and they are the most damaging rays. Fortunately, gamma rays don’t penetrate Earth’s atmosphere.
    ::可见光是人类唯一能看到的光线。 不同可见光的波长不同,颜色不同。 无线电波有最长的波长。 无线电波有最长的波长, 它们的能量也最少。 红外线光有波长,人类看不到, 但我们能感觉到它们是热的。 大气层吸收红外线光。 紫外线(UV)光以波长太短,人类看不到。 最活跃的紫外线对生命有害。 大气吸收了大部分来自太阳的紫外线。 伽马射线的能量最高,是破坏力最大的射线。 幸运的是,伽马射线没有侵入地球的大气层。

    Summary
    ::摘要

    • Gamma rays have the most energy of any photons emitted by the sun while radio waves have the least. This range and the radiations within it make up the electromagnetic spectrum.
      ::伽马射线最能吸收太阳释放的光子,而无线电波的能量最少。这种射程和射线中的辐射构成电磁波谱。
    • Solar energy travels in photons. Photons travel in waves, which make up electromagnetic radiation.
      ::太阳能以光子为载体,光子以波为载体,由电磁辐射组成。
    • Visible light is the wavelengths of light humans can see.
      ::可见光是光的波长 人类可以看到。

    Review
    ::回顾

    1. What is a photon? How does energy travel as photons?
      ::什么是光子?能源如何作为光子进行旅行?
    1. What is visible light? What has longer wavelengths than visible light? Shorter wavelengths?
      ::什么是可见光?比可见光更长的波长是什么?更短的波长是什么?
    1. What is the electromagnetic spectrum?
      ::电磁频谱是什么?

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. What is the electromagnetic spectrum?
      ::电磁频谱是什么?
    1. Which waves have the longest wavelengths?
      ::哪个波有最长的波长?
    1. What has the shortest wavelengths?
      ::最短波长是什么?
    1. Why is the visible spectrum important?
      ::为什么可见的频谱很重要?
    1. Stars are far away yet astronomers can tell when they are made of hydrogen. How?
      ::恒星离地球很远,但天文学家却知道它们是何时由氢制成的