Crazy Optics Phenomenon (NEED HELP )

[bgodea]

I really need to figure this out.

I was driving down a straight road with the sun to my right at an 85* angle. You would expect the light rays to appear straight because light cannot bend, but the the rays appear to bend across the glass. Can anyone help me explain this...? I know it has something to do with refraction, but I'm exactly sure.

Any help would be greatly Appreciated.

 

[Hootenanny]

Light indeed changes direction when it meets an interface between two areas of different optical density. This is mathematically defined by Snell's law.

 

[bgodea]

I know there is refraction by snells law and what I see through the window would not be exactly the path of the original light, but what explains the appearance of the light bending?

 

[Hootenanny]

What do you mean by 'bending'?

 

[bgodea]

I can visibely see the rays from the sun hitting the cars windshield and the visible rays from the sun to my windshield have a definite curvature.

 

[Hootenanny]

In which direction are they curving?

 

[bgodea]

check out the pic

 

[bgodea]

well the curves are concave with respect to the bottom right of the windsheild

 

[Hootenanny]

I've heard of light bending due to very massive objects, but not in glass. But that's just me. I'm sure someone has an answer. Do you have any theories by the way?

 

[bgodea]

i can't explain it right now. I know the glass has a slight curvature itself and that the glass is polarized, so that might have something to do with the effect.

Probably the best theory i have is that the light rays are right at the critical angle of the glass so that there is almost total internal reflection in the glass but not quite. The light goes into total internal reflection and then comes out at different points as a function with the curvature that I see.

Does anybody think this is possible?

 

[berkeman]

The picture is still pending approval as an attachment, but my guess is that it's just distortion from the curved glass. How long does it take for attachments to get approved typically?

 

[bgodea]

anybody know?

 

[DaveC426913]

Yes, I have seen this in my own car. The edges of the windshield refract differently than the rest. Any object you view through it (nevermind sun rays, just look at strsight lines on the road) will look curved.

 

[RVBuckeye]

It's probbly due to the type of glass in the windshield. Nowadays, windshields are made (and I'm not sure of the exact term) with some sort of embedded material which prevents the glass from shattering upon impact. Even though it appears clear.

Edit:

http://computer.howstuffworks.com/question508.htm

Automakers began using laminated safety glass, also known as auto glass, for automobile windshields in 1927. To make laminated safety glass, the manufacturer sandwiches a thin layer of flexible clear plastic film called polyvinyl butyral (PVB) between two or more pieces of glass. The plastic film holds the glass in place when the glass breaks, helping to lessen injuries from flying glass. The film also can stretch, yet the glass still sticks to it. It is also quite difficult to penetrate laminated safety glass, compared to normal window pane glass. The "sandwich with some give" that laminated safety glass is made of also helps hold the occupants in a vehicle! Banks use a multiple-layer laminated glass to help stop bullets.
Laminated safety glass has two other additional benefits:

It reduces transmission of high frequency sound.
It blocks 97 percent of ultraviolet radiation.