We 'see' objects because they either 'emit' or 'reflect' light. Lets say there are two balls of equal size one 10 feet away another 30 feet away. Both the balls reflect light, what information on the "photons" (or waves) say that this light was reflected from which object and how does it tell the retina how far the object is?
2006-09-06 05:47:03 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Physics
If the object emits light then we see it through its image recorded on the retina of the eye using the interpretative power of brain. But when the object is not emitting its own light then we see it by the light scattered by the object. This scattered light helps in forming the image of the object on retina and again we see the image with the help of our brain. It must be noted here if the object happens to be a perfect mirror reflecting the light as per the laws of reflection then the object or in this case the p[erfect mirror is invisible to the eye. Light makes things visible but light itself is invisible. So also the mirror just the changes the direction of the light rays falling on it. I would like to explain it furher if I am asked some queries on my answer.
2006-09-06 08:28:03 · answer #1 · answered by Let'slearntothink 7 · 0⤊ 0⤋
There are several methods the brain/eye system uses to tell distance.
Binocular vision (parallax) is #1 and works well at 10 to 30 ft.
Focus: for closer objects the eye focus is interpreted. For most people, at 10 feet we are able to tell by focus that the object is closer than 30 feet.
General scene: Any other objects can provide clues - most obviously objects in-front of or behind.
Relative size: your mind will assume the two balls are the same size and so the "smaller" looking one is farther away
Brightness: We always treat brighter objects as closer (all other things equal)
Haze: particularly for distant objects we use haze as a measure of distance.
Probably a few more I've forgotten!
2006-09-06 13:08:22 · answer #2 · answered by bubsir 4 · 0⤊ 0⤋
If light was a wave your eyes would have a tough time trying to follow something that is continually changing(a wave moving up and down)
2006-09-06 12:54:17 · answer #3 · answered by goring 6 · 0⤊ 0⤋
Your brain makes an instant inherent deduction on which is which.
2006-09-06 12:53:53 · answer #4 · answered by Sick Puppy 7 · 0⤊ 0⤋