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Strange glow from TV that is off.

  1. Jul 9, 2004 #1
    I don't know where this will end up, but I am going to start it here. A few nights ago my wife and I where watching TV in the bedroom, we turned off the TV and the light over the bed and went to sleep. After a few minutes (maybe five or ten, I woke up and looked at the TV. It was glowing, but here is the strange part, the lightbulb over the bed was also glowing and so were the fan lightbulbs, which had not been on. They all shared the same bluish glow of the TV, not reflected, but appeared to be internally glowing.

    Is this a known phenomenon? I can sort of understand the TV glowing, but what is up with the light bulbs? Can anyone offer some explanation?
     
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  3. Jul 9, 2004 #2

    ZapperZ

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    You didn't say if these light bulbs have a phosphor coatings on them. If they do, then the glow you noticed on them, and on your TV also (assuming it isn't an flat-screen LCD or plasma display) is due to phosphorescence. The light bulbs probably are glowing due to the ambient light when you had other lights in the room or light from the TV when it was on. The phosphorescence can linger for quite a while after the light source is turned off, unlike fluorescence, which is turned off immediately.

    Zz.
     
  4. Jul 9, 2004 #3
    Thanks ZapperZ, that makes sense. They are the soft white type incandescent lightbulbs, I guess there could be phosphorescence in that coating. It is a strange thing to see though.
     
  5. Jul 9, 2004 #4

    LURCH

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    If you want to see something even stranger, try a little form of entertainment my cousins and I used to do when we were quite young; "TV art". Place your hand against the television screen, with the television off but the lights in the room on. Close your eyes and cover them with your free hand so that you will have good night vision when the lights go off. Turn off the lights, remove your hand from the screen, and look at the screen. You will see a ghostly after image of your hand there. If you have a fairly large television set, you can press your face against it, and leave and after image of your own silhouette. This can look rather creepy in the dark!
     
  6. Jul 9, 2004 #5

    Chi Meson

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    Another TV phenomenon which isn't so much a mistery, but I still can't figure out the mechanics of it:

    It only happened with a black & white (monochrome) set, but after it was on for a while, a large static build-up would be on the screen. With lights out and the TV off, you could touch the screen and create a glow that started right at your fingertip and then moved out in a circle across the scree (like a ripple in water). Color TV sets don't do this, so I can't continue my experiments. :frown:
     
  7. Mar 25, 2007 #6
    This is due too phosphorescence. For Example, when an object such as your television gets a great amount of light exposure, a few minutes after it is turned off it will glow for a short period of time.
     
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