Good questions. Let's start with the science and move into the parallels after...
"white is the combination of all the colors of the visible light spectrum. If all the wavelengths of the visible light spectrum give the appearance of white, then none of the wavelengths would lead to the appearance of black. Once more, black is not actually a color. Technically speaking, black is merely the absence of the wavelengths of the visible light spectrum. "
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The Electromagnetic and Visible Spectra
When you look up into the sky at night, most of what you see is space. When people hear the word space they often think about being in an environment like my astronaut avatar. If you think about it, what is
space? It is literally just that, space in it's purest form. If someone tried to give me a free couch, I'd have to tell them I couldn't take it because I don't have enough floor space--I don't have enough
nothing to add
something. Technically, this isn't pure space, because it is occupied by atmospheric gases, which are also something. This is why space is considered a vacuum (compared to our pressurized atmosphere) because molecules naturally disperse from an area of high density to little or no density.
Oh well, it was probably covered with mystery stains and smelled like stale Doritos. Anyways, if space is absolute nothingness, then the vast black night sky is mostly nothing. It looks like it could be something, because we can replicate the color black on an object or paper and still touch and feel it. Considering all of this, does it make sense to refer to darkness as something rather than nothing? Does it make sense to say you are observing darkness rather than an absence of light? Similarly, we must define other things in relation to what is rather than what it is not. 1+1=2. It would take me an eternity to tell you every number 1+1 does not equal. Once we recognize that there is only a single right answer to any question then we can begin to classify everything else in relation to that.
"But Circle, haven't you heard there is more than one way to skin a cat?" Yes, there is more than one way of accomplishing something, but that is like saying there is more than one answers that are "pretty close" to a complex math problem. You can find the right answer through trying other answers that are wrong, but to seek wrong answers on purpose will in no way help you reach the right one any faster.
Dark and light do not "balance" each other out. There is what is [right, true, good] and what is not. What is cannot equal what is not, 1=/=0. Balance is only obtained through equal amounts of what exists. Also, I think the belief that we are in a state of universal balance or will ever reach one is the greatest assumption of all.