<blockquote><font class="small">In reply to:</font><hr /><p>The specimen undergoes a series of changes that involves the light spectrum, and I want to know the correlations to particles/waves, atmospheric pressure, etc. You appear to be a chemist, and you’re certainly someone that should be involved.<br /><br />With respect to Ultraviolet & Infrared Light, I stated that violet is a by-product of red and blue, as in ultrared and ultrablue. Why wouldn’t there be ultrayellow, and ultragreen as well?<br /><br />Could they be undiscovered colors, if not, then why? <p><hr /></p></p></blockquote><br /><br />I don't think you understood my earlier post about the anatomy of the eye.<br /><br />Color as you are describing it is a phenomenon produced by the anatomy of the retina, not by any unique property of light itself. It is the way we *perceive* visible light. It is so fundamental to our understanding of the world around us that it is difficult to realize that primary colors are defined by our eyes, not by light itself. Mixing red with blue to produce violet only works because of the way it stimulates our cones. We perceive violet when the red and blue cones are both being stimulated to the same or a similar degree.<br /><br />"Ultrayellow" would be green. This is because in this context "ultra" means "a little higher frequency than". And green is what's higher frequency than yellow.<br /><br />However, ultraviolet is not a combination of ultrared and ultrablue. Ultrablue *is* violet, by definition, and since primary color combinations only apply to visible frequencies, you can't get ultraviolet by combining visible light. Ultraviolet does not stimulate the cones in the human eye. It is too high a frequency. The experience may be different for butterflies and bees, which can see in ultraviolet, and presumably snakes that see in infrared also have a different experience than we do.<br /><br />If we had a different structure inside our retinas, and perhaps had four different cones inst <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>