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What does darker actually mean

  1. Sep 5, 2015 #1
    when an object it in a setting where there is less light lets say a room with only a small window or when the sun is setting why is it that everything around you looks darker is it that there are less photons?. and if that is the case then if you would put a object in a brighter or a place with more photons would the object look more colorful would it just get more and more colorful as you increased the amount of photons ?

    can some one please tell me how this works much thanks, aiop
  2. jcsd
  3. Sep 5, 2015 #2


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    It's true that in a darker room there are less photons. However, concerning how much color you see, there is a biological component. Your eyes cannot detect color as well in dim light. It has to do with the cells in your eye and not with the properties of the photons.
  4. Sep 5, 2015 #3


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    The human eye has two different types of light-sensing cells. One kind is sensitive to color but requires fairly bright light to work. The other only senses how bright the light is but not the color, so produces black-and-white images in dim light.
  5. Sep 5, 2015 #4


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    Yes, less photons makes things look darker. But there is more going on. In relative darkness you can still see a lot but distinguish less color.
    The eye + brain is a powerful combination. You think you see color all around but in fact you see more color in the direction you are looking directly than in the periphery. You can check this in relative darkness by looking at e.g. the red digits of an alarm clock. If you look away they don't appear red but light grey.

    Brightness and color are picked up by in different ways by different light-sensitive cells. See here
  6. Sep 5, 2015 #5
    Les light makes things look darker.
    Replacing "light" with "photons" does not help much to understand the basics of light and electromagnetic waves.
  7. Sep 6, 2015 #6
    I am not sure how that works are you saying that the amount of photons is not a property of any individual photon, or that a collection of photons has no effect upon how much an object is illuminated.Two photons will react with your eye better than one.It's by use of your eyes that photons were first detected.
  8. Sep 6, 2015 #7
    How does that work?
  9. Sep 6, 2015 #8


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    Maybe an analogy would help. Imagine a bunch of balls that all have numbers on them. Suppose you have 10 balls that are labeled number "1" and 50 balls that are labeled "2". It's as if you have two kinds of sensors. The first kind can tell how many total balls are present. The second cannot do that but, if there are enough total balls present, it can tell what proportion of them have "1" on them versus "2". In this analogy, the total number of balls is the total number of photons and the numbers on the balls are colors. Light is a wave, and a photon is an "excitation of a wave". What that means takes a lot of unpacking, but you can think of each photon having a color associated with it, just like each ball has a number written on it.
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