Notices
Results 1 to 3 of 3

Thread: reflection of light for vision

  1. #1 reflection of light for vision 
    Forum Junior
    Join Date
    Jun 2006
    Posts
    264
    OK so, I was doing a little thought experiment and I have a few questions. As I'm sure everyone here knows, when we see an object, we are actually seeing light reflected off the object. Also we know that angle of reflection = angle of refraction.

    Here's the experiment, We have a light source that emits a powerful, but very narrow beam of light. If you're light source is hitting an object at an angle of 10 degrees, why can you see the object if you are 45 degrees from it?

    I had a couple ideas of possibilities although they are probably wrong.
    1. Since the particles in an object vibrate, it causes the photons to bounce every direction in 10 degrees. If so, theoretically if you could freeze an object to 0 degrees kelvin and were to try the same experiment, would the object only be visible at 10 degrees on the other side (or 170 degrees)?

    2. Every object has crystalline properties to a certain extent and the light bounces around inside and comes back out in all directions.

    Any thoughts?


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Bachelors Degree
    Join Date
    May 2007
    Location
    NC USA
    Posts
    488
    In the ideal case, a narrow beam in a dark room bouncing off a perfect reflector, you would be able to see the light only if your eye were along the reflected path. If you were outside of this path you would see nothing.

    In real life we do not have such perfect conditions. Generally there is plenty of stray light, and this light illuminates everything in the room. Also, reflectors are not perfect; their surfaces are not perfectly true planes. Therefore a tiny amount of the incident light is reflected by surface imperfections to all directions, and an observer should be able to detect the object from any position.

    Molecular movement is not a factor. Nor do we need to invoke surface penetration by the incident light even though it does occur to a small extent.

    Finally, forget photons -- as usual. Your question is easily handled by classical physics, and confirmed by quantum physics only with massive difficulty.
    *


    Reply With Quote  
     

  4. #3  
    Forum Junior
    Join Date
    Jun 2006
    Posts
    264
    so it's just imperfections, fair enough! Thanks and by saying photons I wasn't trying to go deeper, just how I was referring to the light. :P
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •