Are light rays physical? When it reflects off of the objects. After a while, would the object show signs of wear. Maybe in a million years or something, cause if it does then what would the rate be?

Sunlight can bleach colours...

Light is made up of wave-particles called photons, they are physically real.

 

If you look at some black plastic that has been outside for a while it'll look white in places. Or PVC widows turn yellow after being in sunlight, or when you have some wallpaper in direct sunlight for part of the day compare it to some that's been behind a piece of furniture, so yes light can cause ware and tear. The amount of this depends on what it's hitting, it's intensity and the energy of the photons.

cool cool, thanks ^^

Light interacts with the atoms in the material when it strikes it. The corresponding effects depend on the frequency of the light and the atomic structure of the material. Materials that are not completely transparent either absorb light or reflect it. When an object absorbs light, the energy of the oscillating electrons increases the motion of the the atoms of that object instead of going back to light. This heats up the object. And I think that the increasing temperature causes the object to undergo chemical change. And it is this chemical reaction that alters some physical properities of the object, such as it's color n shape, n makes it ware out. The rate depends on the material itself, light's intensity, n the lenght of the time of interaction.

Also consider that energy outside the visible spectrum, UVs probably play an even bigger role in those chemical reactions. After all, they have a great deal more energy and even though our atmosphere takes care of alot of it, a fair amount still makes it through, right?

 

BTW what particals are are UV's considered to be...if at all.

BTW what particals are are UV's considered to be...if at all.

 

Photons, just like any other quantum of EM radiation.