dimreepr Posted January 29, 2018 Posted January 29, 2018 15 minutes ago, Furyan5 said: But by now I'm sure the answer is obvious. Like it or not. Furyan out. Ever had that awkward mike drop moment?
koti Posted January 29, 2018 Posted January 29, 2018 41 minutes ago, dimreepr said: Ever had that awkward mike drop moment? How does he post if he was suspended yesterday ?
dimreepr Posted January 29, 2018 Posted January 29, 2018 3 minutes ago, koti said: How does he post if he was suspended yesterday ? Awkwardly...
swansont Posted January 29, 2018 Posted January 29, 2018 1 hour ago, koti said: How does he post if he was suspended yesterday ? Short suspension. 1
studiot Posted January 29, 2018 Posted January 29, 2018 I would like to announce that I have seen the light. Halleluja brothers and sisters I have become a Jesuit. (So light can be seen)
beecee Posted January 29, 2018 Posted January 29, 2018 (edited) 9 hours ago, Furyan5 said: Do you get it now? The fruit bowl you see is 'the image created inside your brain'. When you look up at the sky, you see, 'the representation created by your brain'. When you hold your hand up in front of your face, you see, 'the representation of your hand, created by your brain'. You never see the 'outside' world. You only ever see the 'representation'. You don't see direct reality, you see indirect reality. Subjectively. Firstly what you need to do is use the "quote" function properly...secondly, if there were no photons of light, you would just see the absence of colour, or black. The rest is simply philosophical jargon. 8 hours ago, Furyan5 said: Your eyes see nothing. NOTHING! . And the answer is NO! WE CAN'T! Posting in upper case letters does not make you correct, nor change the fact that the colour of any object depends in the first instance, on the frequency of the visible EMS that is reflected from that body to our eyes. Light/photons are certainly visible to our eyes, otherwise the world would be permanently black. Edited January 29, 2018 by beecee 1
koti Posted January 29, 2018 Posted January 29, 2018 1 hour ago, swansont said: Short suspension. He caught swansont on a good day I see.
Strange Posted January 29, 2018 Posted January 29, 2018 1 hour ago, beecee said: Posting in upper case letters does not make you correct, He’s lost it.
Furyan5 Posted January 29, 2018 Posted January 29, 2018 5 hours ago, swansont said: More precisely, physicists aren't equipped to answer in a neurological context. But we don't have a neurological context. This would not be the first instance of physics (or some discipline) and <some other discipline> giving different answers because of the context of their respective fields. But you keep trying to bring neurology (and philosophy) to a physics discussion. So you're saying, from a physics perspective, light is visible, but generally speaking, it's not.
MigL Posted January 29, 2018 Posted January 29, 2018 Just because his discussion methods were a little unorthodox ( and a little rude ) doesn't make him wrong. And I will say again that most of this discussion is pointless ( but otherwise interesting ) as its mostly about semantics... But what our eyes 'see' or detect is the interaction of only certain frequencies of EM radiation with out detector cells. Why do some 'colors' appear brighter than others when there is no change in intensity of the EM radiation ? Why do we not see infrared/microwave radiation when every warm body is emitting it ( even in the dark BeeCee ) ? "Visible" light interacts with our receptor cells. "Invisible" light such as infrared or ultraviolet does not. In a Physics discussion 'light' is EM radiation, not a specific subset of the spectrum ( that's why there is a definition for 'visible' light ). So while you may be able to say you can 'see' visible light, you definitely cannot see 'invisible' light. Does that clear things up ? 1
Strange Posted January 29, 2018 Posted January 29, 2018 4 minutes ago, MigL said: And I will say again that most of this discussion is pointless ( but otherwise interesting ) as its mostly about semantics... Absolutely. But whenever that has been pointed out Furious Furyan has denied it!
swansont Posted January 29, 2018 Posted January 29, 2018 22 minutes ago, Furyan5 said: So you're saying, from a physics perspective, light is visible, but generally speaking, it's not. No, as I wouldn't say that the details of neurology fall under "generally speaking". Using the lay definition of see, I'd say we see light. If you shine a light at me, I have the ability to see it. I think it's possible that only when we delve into the minutiae, or otherwise use some esoteric definition, that we will say that you aren't.
Furyan5 Posted January 29, 2018 Posted January 29, 2018 39 minutes ago, Strange said: Absolutely. But whenever that has been pointed out Furious Furyan has denied it! That's because I don't agree. Visible light is the light which makes objects visible. All electromagnetic radiation consists of boson particles, which are not visible to the naked eye.
Furyan5 Posted January 29, 2018 Posted January 29, 2018 14 hours ago, swansont said: No, as I wouldn't say that the details of neurology fall under "generally speaking". Using the lay definition of see, I'd say we see light. If you shine a light at me, I have the ability to see it. You do realize the the brightness you see is subjective right? That it's a visual sensation and not a property of light itself. Just like color. You perceive brightness, because of light. You don't perceive light itself. 14 hours ago, swansont said: I think it's possible that only when we delve into the minutiae, or otherwise use some esoteric definition, that we will say that you aren't.
Furyan5 Posted January 29, 2018 Posted January 29, 2018 (edited) 1 hour ago, MigL said: Just because his discussion methods were a little unorthodox ( and a little rude ) doesn't make him wrong. And I will say again that most of this discussion is pointless ( but otherwise interesting ) as its mostly about semantics... But what our eyes 'see' or detect is the interaction of only certain frequencies of EM radiation with out detector cells. Why do some 'colors' appear brighter than others when there is no change in intensity of the EM radiation ? Why do we not see infrared/microwave radiation when every warm body is emitting it ( even in the dark BeeCee ) ? "Visible" light interacts with our receptor cells. "Invisible" light such as infrared or ultraviolet does not. In a Physics discussion 'light' is EM radiation, not a specific subset of the spectrum ( that's why there is a definition for 'visible' light ). So while you may be able to say you can 'see' visible light, you definitely cannot see 'invisible' light. Does that clear things up ? Visible light is the EM radiation, detectable by the human eye. I appreciate you trying to help, but you're caving to public opinion. You know from personal experience that light can be detected and yet not seen. http://www.physicsclassroom.com/class/light/Lesson-2/The-Electromagnetic-and-Visible-Spectra Skip to the part Visible Light Spectrum. Interestingly, this is a physics site. Edited January 29, 2018 by Furyan5 Clarifying
beecee Posted January 29, 2018 Posted January 29, 2018 3 hours ago, MigL said: But what our eyes 'see' or detect is the interaction of only certain frequencies of EM radiation with out detector cells. Why do some 'colors' appear brighter than others when there is no change in intensity of the EM radiation ? Why do we not see infrared/microwave radiation when every warm body is emitting it ( even in the dark BeeCee ) ? "Visible" light interacts with our receptor cells. "Invisible" light such as infrared or ultraviolet does not. In a Physics discussion 'light' is EM radiation, not a specific subset of the spectrum ( that's why there is a definition for 'visible' light ). So while you may be able to say you can 'see' visible light, you definitely cannot see 'invisible' light. Does that clear things up ? Clear as an Orange in the dark!!
koti Posted January 30, 2018 Posted January 30, 2018 4 hours ago, MigL said: Just because his discussion methods were a little unorthodox ( and a little rude ) doesn't make him wrong. And I will say again that most of this discussion is pointless ( but otherwise interesting ) as its mostly about semantics... But what our eyes 'see' or detect is the interaction of only certain frequencies of EM radiation with out detector cells. Why do some 'colors' appear brighter than others when there is no change in intensity of the EM radiation ? Why do we not see infrared/microwave radiation when every warm body is emitting it ( even in the dark BeeCee ) ? "Visible" light interacts with our receptor cells. "Invisible" light such as infrared or ultraviolet does not. In a Physics discussion 'light' is EM radiation, not a specific subset of the spectrum ( that's why there is a definition for 'visible' light ). So while you may be able to say you can 'see' visible light, you definitely cannot see 'invisible' light. Does that clear things up ? Do you mean does that bring light to Furyan5's understanding of the OP? I doubt it. +1 though.
MigL Posted January 30, 2018 Posted January 30, 2018 Thanks Koti. Furyan5 may have taken this discussion a little too seriously. You gotta have some fun.
swansont Posted January 30, 2018 Posted January 30, 2018 13 hours ago, Furyan5 said: You do realize the the brightness you see is subjective right? That it's a visual sensation and not a property of light itself. Just like color. You perceive brightness, because of light. You don't perceive light itself. Brightness isn't the issue under discussion. Maybe you could answer the question I asked earlier. When we look at a neon light, are we seeing the atoms?
geordief Posted January 30, 2018 Posted January 30, 2018 (edited) 24 minutes ago, swansont said: When we look at a neon light, are we seeing the atoms? I was wondering something similar myself. When we look directly back at a beam of light (such as a torch) are we actually "seeing" the filament/source ? (buried in the glare) Is there any worthwhile distinction between detecting light directly from its source and detecting it after it has reflected off a third ( or later object) ? Apart from "3rd party" sources allowing us to map the world around us....... Edited January 30, 2018 by geordief 1
Eise Posted January 30, 2018 Posted January 30, 2018 47 minutes ago, geordief said: Is there any worthwhile distinction between detecting light directly from its source and detecting it after it has reflected off a third ( or later object) ? Worthwhile? At most in the context of this discussion... To your question: Yes, there is. If you see a car, then you see it because it reflects light. In such a case it is pretty unusual to say "I see light...wait... from the light I deduce that it is reflected by a car. So there must be a car there!" No, you would say "I see a car". Now try to see a light beam passing next to you (so it is not detected by your eyes! No single photon of the light beam enters your eyes, it is not shining on a screen or a wall). Shining light on it will not help you to see the light beam. In this sense (but only in this sense!) one could say that light is invisible. You cannot make it visible by pointing a torch at it, as you could do with a car. Worthwhile? 22 hours ago, Furyan5 said: If the fact we agree on is 'that we can't see light' (visually perceive photons), then yes. Facts are expressed by words. If we can agree on the meaning of words, only then we can possibly agree on the facts. Otherwise the same sentences mean different things to different people. Maybe it would help to formulate the facts unambiguously. So let's try 2 contrasting facts: You can make a material, macroscopic object visible by shining light on it (e.g. a car). You cannot make a light beam (that passes by) visible by shining light on it. Do we all agree on these 2 facts?
Furyan5 Posted January 30, 2018 Posted January 30, 2018 8 minutes ago, Eise said: Worthwhile? At most in the context of this discussion... To your question: Yes, there is. If you see a car, then you see it because it reflects light. In such a case it is pretty unusual to say "I see light...wait... from the light I deduce that it is reflected by a car. So there must be a car there!" No, you would say "I see a car". Now try to see a light beam passing next to you (so it is not detected by your eyes! No single photon of the light beam enters your eyes, it is not shining on a screen or a wall). Shining light on it will not help you to see the light beam. In this sense (but only in this sense!) one could say that light is invisible. You cannot make it visible by pointing a torch at it, as you could do with a car. Worthwhile? So, it's invisible, unless it hits your eye directly. And if it hits your eye, you see the source of the light. Visible light is the light which allows us to see.
Furyan5 Posted January 30, 2018 Posted January 30, 2018 (edited) 18 minutes ago, Eise said: Worthwhile? At most in the context of this discussion... To your question: Yes, there is. If you see a car, then you see it because it reflects light. In such a case it is pretty unusual to say "I see light...wait... from the light I deduce that it is reflected by a car. So there must be a car there!" No, you would say "I see a car". Now try to see a light beam passing next to you (so it is not detected by your eyes! No single photon of the light beam enters your eyes, it is not shining on a screen or a wall). Shining light on it will not help you to see the light beam. In this sense (but only in this sense!) one could say that light is invisible. You cannot make it visible by pointing a torch at it, as you could do with a car. Worthwhile? Facts are expressed by words. If we can agree on the meaning of words, only then we can possibly agree on the facts. Otherwise the same sentences mean different things to different people. Maybe it would help to formulate the facts unambiguously. So let's try 2 contrasting facts: You can make a material, macroscopic object visible by shining light on it (e.g. a car). You cannot make a light beam (that passes by) visible by shining light on it. Do we all agree on these 2 facts? Yes, we agree so far. Since this narrow band of wavelengths is the means by which humans see, we refer to it as the visible light spectrum. (these are not my words, but copied from a physics web page). http://www.physicsclassroom.com/class/light/Lesson-2/The-Electromagnetic-and-Visible-Spectra Edited January 30, 2018 by Furyan5 Link provided
studiot Posted January 30, 2018 Posted January 30, 2018 21 minutes ago, Eise said: Worthwhile? At most in the context of this discussion... To your question: Yes, there is. If you see a car, then you see it because it reflects light. In such a case it is pretty unusual to say "I see light...wait... from the light I deduce that it is reflected by a car. So there must be a car there!" No, you would say "I see a car". Now try to see a light beam passing next to you (so it is not detected by your eyes! No single photon of the light beam enters your eyes, it is not shining on a screen or a wall). Shining light on it will not help you to see the light beam. In this sense (but only in this sense!) one could say that light is invisible. You cannot make it visible by pointing a torch at it, as you could do with a car. Worthwhile? Facts are expressed by words. If we can agree on the meaning of words, only then we can possibly agree on the facts. Otherwise the same sentences mean different things to different people. Maybe it would help to formulate the facts unambiguously. So let's try 2 contrasting facts: You can make a material, macroscopic object visible by shining light on it (e.g. a car). You cannot make a light beam (that passes by) visible by shining light on it. Do we all agree on these 2 facts? You can easily turn this line of argument on its head First let us agree that the car is a toy car so that we can perform the experiment in a darkened room. a) Remove the torch. b) Paint the car with electroluminescen paint. c) Connect the car to a suitable electric source via a switch. In the darkened room can you see the car? d) Close the switch. What do you see? You say "I can see the car" You do not say "I can see the light from the car" However now look sideways at the car so you can't directly see it. You can see a glow from a light source. You now say "I can see the light from the car" because you can't actually see the car In regard to your premises 1) Agreed 2) You do not need to shine a light on light to see it.
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