来自《耶鲁大学开放课程：生物医学工程探索 第20集 第20集》

• 
  
  or slightly less than a micron.
  或者略小于一微米
• 
  
  It's around 400 nanometers to 700 nanometers is the visible spectrum.
  四百到七百纳米部分是可见光光谱
• 
  
  Now, why is this visible spectrum?
  那么 为什么这部分光是可见的呢
• 
  
  Because when radiation with this wavelength hits your eye,
  因为当这一波长的辐射接触你的眼睛
• 
  
  it makes a change in the cells inside your eye
  它会引起眼睛内部细胞的变化
• 
  
  and allows your retina to make an image.
  并在你的视网膜上成像
• 
  
  It's only light of those particular wavelengths
  只有这一特定波长范围的光
• 
  
  that can interact productively with this particular special biological object
  才能与特殊的生物组织 即视网膜反应
• 
  
  called the retina and that's all the light that we can see.
  这就是我们能看到的全部光线
• 
  
  There's electromagnetic radiation of
  而在可见光光谱之外
• 
  
  all different wavelengths outside of the visible spectrum.
  有各种不同波长的电磁辐射
• 
  
  In fact, one of the things you should notice here
  事实上 有一件事值得注意