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Light
Sept 16, 2012 10:10:37 GMT 1
Post by striker16 on Sept 16, 2012 10:10:37 GMT 1
Why does blue light have high energy photons while red light has low energy photons?
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Light
Sept 23, 2012 7:23:37 GMT 1
Post by fascinating on Sept 23, 2012 7:23:37 GMT 1
Do you mean "How is it that low energy photons produce red and high energy photons produce blue?"
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Light
Sept 23, 2012 15:58:48 GMT 1
Post by striker16 on Sept 23, 2012 15:58:48 GMT 1
Do you mean "How is it that low energy photons produce red and high energy photons produce blue?" Yes, I suppose I do.
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Light
Sept 24, 2012 3:54:47 GMT 1
Post by mrsonde on Sept 24, 2012 3:54:47 GMT 1
And what's the difference in the two formulations?
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Light
Sept 24, 2012 7:31:28 GMT 1
Post by fascinating on Sept 24, 2012 7:31:28 GMT 1
On my understanding, light is simply electromagnetic radiation, travelling at different wavelengths/frequencies, and colour is not an intrinsic property of it. When we perceive light through our eyes, three different kinds of cone cells have three differing responses depending on the wavelength of the light (the differing responses are governed by the exact nature of the protein (rhodopsin I think) within the cell which reacts to the individual photon event). That is why there is this idea that there are 3 different colours, red , green and blue, which mixing gives all other colours. See www.physicsclassroom.com/class/light/u12l2b.cfm
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Light
Sept 24, 2012 8:45:04 GMT 1
Post by striker16 on Sept 24, 2012 8:45:04 GMT 1
On my understanding, light is simply electromagnetic radiation, travelling at different wavelengths/frequencies, and colour is not an intrinsic property of it. When we perceive light through our eyes, three different kinds of cone cells have three differing responses depending on the wavelength of the light (the differing responses are governed by the exact nature of the protein (rhodopsin I think) within the cell which reacts to the individual photon event). That is why there is this idea that there are 3 different colours, red , green and blue, which mixing gives all other colours. See www.physicsclassroom.com/class/light/u12l2b.cfm Thanks for that, fascinating.
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Light
Sept 25, 2012 13:33:22 GMT 1
Post by mrsonde on Sept 25, 2012 13:33:22 GMT 1
On my understanding, light is simply electromagnetic radiation, travelling at different wavelengths/frequencies, and colour is not an intrinsic property of it. This is the standard Galilean-Cartesian-Lockean primary/secondary quality distinction. Whitehead's "bifurcation of nature" simply assumed (there is no, nor could there be, any conceivable evidence for it, and nor does it give greater explanatory power) by most professionally trained scientists. It generates more problems than it answers: which on analysis is none. It leaves us with Descartes' dualism, with reality forever split between matter and mind with no understanding of the relation between the two, or any hope of one. Unpack that idea, please. In science "that is why" normally implies that a causal chain has been described - given event x, the conditions and forces a,b,c... you must get event y. So - what is the causal chain leading from the photons to the colours? Electrochemical impulses from cones are somewhere in the middle...electrochemical neuronal impulses too...and then? Where's the step that says: and voila!, then you inevitably see this thing we call red, blue, green, etcetera?
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Light
Sept 25, 2012 16:01:31 GMT 1
Post by fascinating on Sept 25, 2012 16:01:31 GMT 1
I believe that there is a subjectively-experiencing mind, which is not the same as matter, though, conceivably, the mind might be an epiphenomenon of matter. I suppose that makes me a dualist (but don't worry, it doesn't mean I want to have a dual with you at dawn!).
"So - what is the causal chain leading from the photons to the colours? Electrochemical impulses from cones are somewhere in the middle...electrochemical neuronal impulses too...and then? Where's the step that says: and voila!, then you inevitably see this thing we call red, blue, green, etcetera?"
As there are 3 types of cone cells, with different frequency responses, then there is the physical basis for the production of the information which allows the brain to identify which colour is being seen by the eye. Presumably for most scientists that is just about enough of an explanation.
If you are asking how the physical impulses turn into the subjective-experience/perception of the colour red/green/blue (the actual qualitative feeling of a colour) then nobody knows. To me it is the most interesting question of all, but you don't have to go into that to answer the question in the OP.
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Light
Sept 26, 2012 3:35:13 GMT 1
Post by mrsonde on Sept 26, 2012 3:35:13 GMT 1
I believe that there is a subjectively-experiencing mind, which is not the same as matter, though, conceivably, the mind might be an epiphenomenon of matter. I suppose that makes me a dualist (but don't worry, it doesn't mean I want to have a dual with you at dawn!). It's a respectable enough metaphysical view - historically speaking anyway. Apart from the elastically opaque phrase, "epiphenomenon of matter" (which I suspect could mean anything, or nothing, except anything that that has ever been analysed or understood by anybody), I think the proportion of scientists who agree with your position is now vanishingly small. The number of philosophers who do certainly is, and I'm sure science as a collective must be even more hostile. It's an explanation of how the brain is able to identify which frequency of light is being "seen". You haven't got to the step yet where this information gets translated as "colour". You started off by saying they're different things, remember? ;D That's my point, my good chap! Oh, I think you do! That's exactly what the question in the OP asks. He may not have meant to, mind, but that's another matter.
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Light
Sept 26, 2012 3:49:19 GMT 1
Post by mrsonde on Sept 26, 2012 3:49:19 GMT 1
Let me put it another way then, if you really believe you've answered the question in the OP. What feature of the standard physicist's account of colour perception that you've referred to answers this:
Why does blue light have high energy photons while red light has low energy photons?
as contrasted with, for example, this:
Why does red light have high energy photons while blue light has low energy photons?
or this:
Why does green light have high energy photons while yellow light has low energy photons?
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Light
Sept 26, 2012 7:40:11 GMT 1
Post by fascinating on Sept 26, 2012 7:40:11 GMT 1
I feel that I have answered the question in the OP because the poster himself said. If Striker16 is not satisfied with my answer then I invite him to say so and I will try to come up with a better answer.
I take your point about the way he has worded the question. I suppose that the questions in your last post are meant to convey that the question is meaningless? I would disagree there.
Do you accept the existence of subjective reality? I mean, do you accept that subjective experience is REAL (even if it does not necessarily convey information about objective reality)?
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Light
Sept 26, 2012 9:52:54 GMT 1
Post by striker16 on Sept 26, 2012 9:52:54 GMT 1
If a question is always going to invoke the subjective experiences of whoever is making an observation of this or that phenomenon, then may I respectfully suggest this is wondering into the area of philosophy, not science.
To be perfectly honest, most other MBs I have visited do have a separate philosophy board and this makes sense else you are going to keep conflating science and philosophy which, to some extent can be useful, but generally tends to lead nowhere.
Why hasn't this MB got a philosophy section?
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Light
Sept 26, 2012 11:34:28 GMT 1
Post by fascinating on Sept 26, 2012 11:34:28 GMT 1
Don't worry about it, I don't think anybody is going to prevent us doing a little philosophising, and anyway we can always expostulate in the "friendly" chat room.
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Light
Sept 26, 2012 11:52:48 GMT 1
Post by striker16 on Sept 26, 2012 11:52:48 GMT 1
Don't worry about it, I don't think anybody is going to prevent us doing a little philosophising, and anyway we can always expostulate in the "friendly" chat room. Well, if you look at my original question, it was posed as a scientific query requiring a scientific answer but seems now have become a deep philosophical issue, which is interesting in itself but not what I required. This is the kind of thing that happens when people are allowed to wonder off-topic too much. In fact, now I seem to have been sidetracked into discussing the policy of this MB rather than the nature of blue and red light! Where's STA when you need her? Often did not follow what she was on about but at least she addressed herself to the science.
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Light
Sept 26, 2012 12:51:16 GMT 1
Post by mrsonde on Sept 26, 2012 12:51:16 GMT 1
I feel that I have answered the question in the OP because the poster himself said. If Striker16 is not satisfied with my answer then I invite him to say so and I will try to come up with a better answer. Yes, I must say, he's a very easily satisfied chap. That possibly accounts for how anyone's got to his age without ever hearing about red, green and blue colour cones. Certainly not. I'm merely pointing out that the answer given has not addressed the question. Yes. I just reject the view it's made up of any different sort of "stuff" as that objective reality - space-time, energy. It's res cogitans that I do not accept the existence of - it's all res extensa. Most scientists would agree with me, incidentally - but then most scientists haven't thought about it much, which is why they still come out with the "colours aren't real" nonsense.
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