(Dec 14, 2019 01:18 AM)Secular Sanity Wrote: [ -> ]So, tell me, if light doesn’t absorb itself, and it doesn't, how is black produced? If you subtract blue then red+green= yellow. Subtract green and red+blue=magenta. Subtract red and then green+blue=cyan. Superimposing all three, Cyan, magenta and yellow produces black. How does that happen, if nothing is absorbed, C2?
The wavelengths cancel each other, by aligning crests with troughs. Like opposite poles negating each other.
(Dec 14, 2019 02:49 AM)Syne Wrote: [ -> ] (Dec 14, 2019 01:18 AM)Secular Sanity Wrote: [ -> ]So, tell me, if light doesn’t absorb itself, and it doesn't, how is black produced? If you subtract blue then red+green= yellow. Subtract green and red+blue=magenta. Subtract red and then green+blue=cyan. Superimposing all three, Cyan, magenta and yellow produces black. How does that happen, if nothing is absorbed, C2?
The wavelengths cancel each other, by aligning crests with troughs. Like opposite poles negating each other.
Yah, a derivative like "cancellation" would be more fitting than "subtraction". The latter just gets confused with the CMY color approach used in print media that's in the reflection category, that it's usually reserved for. We've got no need to even mention the color mixing systems used in the emission (RGB) and reflection categories if the inquiry is instead nothing more than what produces the dark areas of an interference pattern.
That's why I'd like to determine once and for if the latter is truly all this has ever been about in the other thread. And if so we keep it nailed there in interference so it doesn't buzz off to yet somewhere else. Whether dispersion or back to what seemed the original starting place of emission and reflection, or even a new(?) pit stop at scattering.
SS Wrote:So, tell me, if light doesn’t absorb itself, and it doesn't, how is black produced? If you subtract blue then red+green= yellow. Subtract green and red+blue=magenta. Subtract red and then green+blue=cyan. Superimposing all three, Cyan, magenta and yellow produces black. How does that happen, if nothing is absorbed, C2?
I don't think anyone has nailed this (I might have missed it). So, mansplaining here I go.
With ears you can pick out a particular frequency. <Moves to the piano> If I play eight notes at once, all at the same time, Mrs C2 can write down all eight of the notes.
Eyes can't do the frequency equivalent of what (Mrs C2's) ears can do. Eyes have things that are more broadly more sensitive to some frequencies than others but all of the bits are still a bit sensitive to all of the frequencies. I am red-green colour blind. Let's assume I lack any sensors for red (low frequency) light. My green sensors (mid frequency) still respond (a bit) to red light so I'm not blind to red things. I can see red traffic lights and green traffic lights but I identify them as the light at the top and the light at the bottom.
Eyes are very old in evolutionary terms and potentially more advanced and cleverer than the thing that is looking out through them. When I want to get past our local bees they seem to take a while to switch from flower finding mode to navigation mode - it wouldn't surprise me if they aren't looking at a UV screen for finding flowers and another screen for general navigation. In a few seconds they switch from feeding to letting the large mammal through without going into attack mode. I don't know if they actually have an attack mode but I really don't want find out.
Sometimes the brain is smarter than the eyes. There's a type of fish that eats fruit but is colour blind and can't find the fruit. Monkeys aren't colour blind and can find the fruit so the fish have to follow the monkeys to find the fruit.
I don't know how much processing is done before the brain even gets a peek at it but for us mammals the result seems to be 'a colour' rather than anything to do with which of the RGB sensors is actually activated. Mammals may (or may not) have got the best eyes but they are are what they are and that is what we live with. What follows is a consequence of some evolutionary compromise rather than physics.
Back to the piano. Alice gets a colour additive piano and Bob gets a colour subtractive piano. Alice (somehow) presses all the keys in the middle of the piano and we get green. Bob (somehow) presses all of the keys at the top and bottom of his (subtractive) piano and again we get 'green'. Bob's piano is twice as loud as Alice's so he gets 'vibrant green' compared to Alice's green. With Bob's piano we see that the colour is a consequence of the keys he doesn't press. So when he wants to show RGB he doesn't press any keys - which is silence - or black, To get white (obviously) he presses all of the keys at the same time.
</mansplaining>
(Dec 14, 2019 02:44 AM)C C Wrote: [ -> ]Note that SS isn't referring to those subtractive primary colors in their usual reflective context as in inks, dyes, or pigments where molecules do the selective absorbing to yield the colors we perceive in printed media. But as in emissions of light like the additive system of red, green, blue primary colors used in color television or colored beams of light mixing (but via subtractive process, not additive).
You'd also do me a big favor, C2, if you could supply a video or some illustrative documentation that actually demonstrates such a phenomenon. Due to lack of that, I keep defaulting to conceiving this proposed situation as people trying to explain Bigfoot before anyone has straight-up and in unadulterated fashion produced Bigfoot as a fact.
Don't get me wrong -- I do want to witness Bigfoot directly. I'd love to be the equivalent of some hick living under a rock who has, say, never encountered a potato peeler before or is simply experiencing a loud overhead boom in terms of understanding what a potato peeler is. But I do need to see the bloody potato peeler straight-up in the context it seems to initially be introduced in.
EDIT: In a later post, Syne has submitted a response in the different interference category below. That's another matter. If one of these isn't finally, definitely selected as the context truly being discussed here or in the other thread -- and a nail driven into that one in terms of staying put there -- then this is going to remain a tower of babel in terms of confusion (at least for me). Can I finally take it that this topic has never had anything to do with the emission and reflective categories -- that is, certain of their aspects being conflated or hybridized, along with interference amply tossed into the maelstrom? It's just a red-herring I've been wandering down trying to make sense of -- the interference category has always been the actual or only context this centers around?
I’m sorry, C C, but your curiosity is just as strong as mine and as you know, Alice’s initial reaction after falling down the rabbit hole is one of loneliness. Her curiosity led her to a world where everything is assbackwards and she becomes even more lost and confused when her arithmetic (a subject she believed to be unchanging and solid) fails her.
I might be able to show you bigfoot’s footprints in the
other thread.
(Dec 14, 2019 02:49 AM)Syne Wrote: [ -> ]The wavelengths cancel each other, by aligning crests with troughs. Like opposite poles negating each other.
Syne is in step with what I’m thinking, which is really wierd.
If the crests are in step, they combine into a more intense effect. If one crest meets the valley of the other, they cancel and the result is darkness. Nobody has ever made this claim. If this is what is happening, how could we prove it?
(Dec 15, 2019 02:16 AM)confused2 Wrote: [ -> ]Back to the piano. Alice gets a colour additive piano and Bob gets a colour subtractive piano. Alice (somehow) presses all the keys in the middle of the piano and we get green. Bob (somehow) presses all of the keys at the top and bottom of his (subtractive) piano and again we get 'green'. Bob's piano is twice as loud as Alice's so he gets 'vibrant green' compared to Alice's green. With Bob's piano we see that the colour is a consequence of the keys he doesn't press. So when he wants to show RGB he doesn't press any keys - which is silence - or black, To get white (obviously) he presses all of the keys at the same time.
</mansplaining>
So, in other words, Alice is the only one doing any work but Bob is still getting paid for his performance. It figures.
</womansplaining>
Since Bob isn’t doing anything, maybe he could have a drink with Alice.
Here’s my address.
![[Image: 49223288097_6aa2d8fae9_m.jpg]](https://live.staticflickr.com/65535/49223288097_6aa2d8fae9_m.jpg)
Oh, and do you think he’d mind swinging by his little hobby shop and picking up a prism first?
(Dec 15, 2019 06:55 PM)Secular Sanity Wrote: [ -> ] (Dec 14, 2019 02:49 AM)Syne Wrote: [ -> ]The wavelengths cancel each other, by aligning crests with troughs. Like opposite poles negating each other.
Syne is in step with what I’m thinking, which is really wierd.
If the crests are in step, they combine into a more intense effect. If one crest meets the valley of the other, they cancel and the result is darkness. Nobody has ever made this claim. If this is what is happening, how could we prove it?
Um, I'm sure that's a pretty standard physics answer.
(Dec 15, 2019 07:06 PM)Syne Wrote: [ -> ] (Dec 15, 2019 06:55 PM)Secular Sanity Wrote: [ -> ] (Dec 14, 2019 02:49 AM)Syne Wrote: [ -> ]The wavelengths cancel each other, by aligning crests with troughs. Like opposite poles negating each other.
Syne is in step with what I’m thinking, which is really wierd.
If the crests are in step, they combine into a more intense effect. If one crest meets the valley of the other, they cancel and the result is darkness. Nobody has ever made this claim. If this is what is happening, how could we prove it?
Um, I'm sure that's a pretty standard physics answer.
For interference itself, perhaps, but not for the explanation of why cyan, magengta and yellow turn black when they're superimposed. If you've seen or could find that solution, then we'd have our answer.
Different wavelengths can partially interfere, lowering the resultant wavelength (changing the perceived color), and multiple wavelengths can collectively cause total interference. Just a matter of how all the crests and troughs align.
(Dec 15, 2019 07:31 PM)Syne Wrote: [ -> ]Different wavelengths can partially interfere, lowering the resultant wavelength (changing the perceived color), and multiple wavelengths can collectively cause total interference. Just a matter of how all the crests and troughs align.
That's what I was thinking but we don't have any proof.
I wasn’t just trying to just brush off C2's answer. They do use
dichroic filters, which would be similar to what he’s trying to get at with
Bob’s piano but if the light wave isn’t absorbed, Bob’s cyan still contains blue and green and it’s the same for yellow and magenta. If we’re left with deconstructive interference, we’ve got no proof. I have never heard anyone make that claim...ever, have you?