We are delving into an area where sciences meet theology and thus can easily escalate this post high into the nose-bleed section of intellectualism. I shall employ every precaution at my disposal to keep from being confusing as well as leave my aptitude and ability to speak on this subject. *Grin*
Light is invaluable to us both as human beings and photographers. Our bodies require a certain amount of light to continue necessary functions, one of our primary functions being vision.
If we deny light from entering our eyes, our body (after some time) will begin the process of deteriorating the tissues and muscles of our optical ability. Eventually without the use of light to add contrast to things around us and using our eyes we will become blind. This is an observation of a natural process (science being observatory by nature).
As photographers, light is the source of our inspiration. I say this because without light we could not see anything we have photographed.
Now to get to the theory of light: In a closed environment (a studio for example) it is impossible to totally empty it of light. There will be little enough that we receive no benefit from what light is there, however this does not mean that we are devoid of all light.
In the opposite sense it should be impossible to fill a room with light so completely that there is no more room to add light. Perhaps the added light will not be observed, but this does not mean it is not being added.
“Darkness” is the term we use to describe the absence of light. Light however is not the absence of “darkness” but rather “the natural agent that stimulates sight and makes things visible; electromagnetic radiation from about 390 to 740 nm (nano-meter) in wavelength.” Another interesting fact is that the universe in which our habitation exists is similar enough to a vacuum that we measure the speed of light in a vacuum and call it our standard for the speed of light. In a vacuum, light travels 186,282.397 miles per second. No wonder a simple reflector is so effective and flashes can disrupt or enhance the make-up of a photo!
Just some interesting things to ponder.