The first thing that must be said about color is that it is, above all else, what we have defined it to be, and the definitions for what it is can vary based on perspective. Color can be defined on the visual appearance of an object, or based on properties of light. For example, some definitions might state that black is not a color in the strict sense that there is no light ray that creates black (when referring to light, black is the absence of light, whereas white is all colors of light combined). Red, on the other hand, is a term that can describe both the property of certain objects (the notebook is red) as well as a characteristic of light (typically with a wavelength of in the 600-700 nm range).
In physics, color is generally defined within the range of wavelengths that the human eye can detect, called the visible part of the electromagnetic spectrum. That portion of the spectrum is then further broken down by wavelengths, and each part then given a name. As such, usage of the term color, and various colors given name, varies. All that being said, color in general is real and connected to physical phenomena, in that photons have energy values and wavelengths, and we have given names to photons of certain energy values. This series of posts will often refer to color under the understanding that the term is defined as “a characteristic of light”, not merely the property of a physical object.
Posts for this month will start off with some reblogs of older posts about luminescence, shift into information about chromism, and end with some information about the sources of color. New posts written by this blog will have the additional tag June25Posts, relevant reblogs of this blog’s posts will be tagged June25Reblog, and everything else will have the regular relevant tags as normal. (Feel free to check out the color tag, or the structural color tag!)
Image sources: (One—rubies), (Two—pentaamminenitritocobalt(III) chloride), (Three—chlorine gas), (Four—uranium glass), (Five—LEDs), (Six—chromium chloride), (Seven—manganese chloride) (Eight—amorphous boron) (Nine-krypton)
Some color resources to get you started: (Causes of Color) (Physics of Light and Color) (Stanford Introduction to Color Science) (MIT The science of colour and colour vision)
