taniwha Posted June 28, 2014 #26 Share Posted June 28, 2014 Just thought I'd post this: http://static.ddmcdn...full-130404.jpg Nice, if only we had hubble eyes. You have to be kidding? Please tell me you're kidding? Lol. What? Link to comment Share on other sites More sharing options...
Lilly Posted June 28, 2014 #27 Share Posted June 28, 2014 Lol. What? Never mind (I'm getting too old/lack the patience). 2 Link to comment Share on other sites More sharing options...
Duke Wellington Posted June 28, 2014 #28 Share Posted June 28, 2014 (edited) If light is invisible then why do we refer to some wavelengths as VISIBLE light? If we see black so well why can you not see in the dark? Black is NOT a visible colour, it is a total ABSENCE of visible colour. We see the space as black because there is no visible light above the detection level of the human eye in those regions. This is primary school stuff taniwha. In fact you don't even need a primary school education to see that your post is total nonsense, just the ability to think in a very simple, logical manner. It also needs to be pointed out that what we see isn't whats out there. Its our brains idea of whats out there based on electrical impulses from our senses. In truth there is no red, yellow, blue, black or whatever colour. Its our brain which has determined we should experience this area as black and this area as another colour. That is based on what type of photons the eyes detected. Finally our eyes detect less than 0.1% of the electromagnetic radiation wavelengths there are. The universe is full to the brim of photons but our limited eyes just can't sense most of them. For that you need a gamma telescope, a microwave telescope, a x-ray telescope, etc. Edited June 28, 2014 by RabidMongoose 1 Link to comment Share on other sites More sharing options...
taniwha Posted June 28, 2014 #29 Share Posted June 28, 2014 I dont think that the darkness is simply imagined either. Link to comment Share on other sites More sharing options...
Rlyeh Posted June 28, 2014 #30 Share Posted June 28, 2014 By the definition, a photon should be the light and the carrier of heat, which is a fact that becomes obvious the moment you get out to the sunlight. Then how come that it is warmer closer to the ground than in the mountains or outside the atmosphere? If a countless quantity of them sets out from the surface of Sun, why can they only be seen on the objects, but not up, in “the vacuum?” Why they don’t illuminate there, too?How is heat transferred? And how do you illuminate a vacuum?A photon is only another delusion, firmly set in the foundations of physics. Obviously, something else is here present because the term “photon”, both as a particle or a particle and wave, does not correspond to the truth, since the photon does not exist. If we compare it to the light, than the light itself would not exist and therefore, the speed of light would not exist either. There are only waves, matter (the visible one) and the event, occurring in the collisions of waves and matter, the product of which is known as the light. The speed of light exists as long as there is matter and when the matter is gone, the light is gone, too, and if there is no light, it is pointless to talk about its speed.The problem here is ignorance, it seems you've read something and haven't looked up the mechanisms behind heat transfer and light behaviour. Link to comment Share on other sites More sharing options...
Lilly Posted June 28, 2014 #31 Share Posted June 28, 2014 No, no, no...the color of light is characterized by wavelength, frequency and intensity. How we as humans perceive the color is internal but it's not somehow 'created' by us. There are actually more spectral combinations than we humans can even sense. Please (oh please, oh pretty please) go and read this nice Wiki link: http://en.wikipedia.org/wiki/Color#Physics_of_color Link to comment Share on other sites More sharing options...
Weitter Duckss Posted June 28, 2014 Author #32 Share Posted June 28, 2014 Gravity is an attractive force, and it is clear why with the distance is losing strength. It is linked to the source or body. Radiation is not it. It immediately terminated the connection with the body, and yet behave like gravity. It should go unchanged through the "vacuum". So in laboratories. Why is there different? ... The original text is a translation (a university professor Zule), and the rest is google translator. Everything is of Weitter Duckss. Link to comment Share on other sites More sharing options...
Duke Wellington Posted June 28, 2014 #33 Share Posted June 28, 2014 (edited) No, no, no...the color of light is characterized by wavelength, frequency and intensity. How we as humans perceive the color is internal but it's not somehow 'created' by us. There are actually more spectral combinations than we humans can even sense. Please (oh please, oh pretty please) go and read this nice Wiki link: http://en.wikipedia....hysics_of_color You're making assumptions about photons which aren't in the link. Photons are strange little things and don't behave the way most people expect them to. They don't have intensity and they don't have colour. The only property they do have is wavelength. Intensity - If you up the voltage to a lamp so it shines brighter the brightness isn't caused by photons having more energy. Its caused by more photons per second being emitted. If you want evidence you need to read up on black body radiation although its a complicated read for a non-physicist. Colour - Photons don't have colours they have wavelengths some of which are detected by the cells in the back of your eyes. Those cells then send electrical impulses (not something called colour) along the optic nerve to your brain. Your brain uses a tool to create an understanding of the world around you from those electrical impulses called your visual experience. Part of that is colour. If that doesn't clear it up for you consider a colour blind person seeing a green sky and you seeing a blue one. If you still have problems with this then you need a book on psychology or neuroscience both of which will tell you colour is perception not a property of photons. Edited June 28, 2014 by RabidMongoose 1 Link to comment Share on other sites More sharing options...
Weitter Duckss Posted June 28, 2014 Author #34 Share Posted June 28, 2014 How is heat transferred? And how do you illuminate a vacuum? The problem here is ignorance, it seems you've read something and haven't looked up the mechanisms behind heat transfer and light behaviour. I did not understand. Do you have light without heat? Does the heat from the sun expands on unfamiliar way? What warms us in the "vacuum"? If warms us, Why is without us so cold in the Universe? Link to comment Share on other sites More sharing options...
Weitter Duckss Posted June 28, 2014 Author #35 Share Posted June 28, 2014 You're making assumptions about photons which aren't in the link. Photons are strange little things and don't behave the way most people expect them to. They don't have intensity and they don't have colour. The only property they do have is wavelength. Intensity - If you up the voltage to a lamp so it shines brighter the brightness isn't caused by photons having more energy. Its caused by more photons per second being emitted. If you want evidence you need to read up on black body radiation although its a complicated read for a non-physicist. Colour - Photons don't have colours they have wavelengths some of which are detected by the cells in the back of your eyes. Those cells then send electrical impulses (not something called colour) along the optic nerve to your brain. Your brain uses a tool to create an understanding of the world around you from those electrical impulses called your visual experience. Part of that is colour. If that doesn't clear it up for you consider a colour blind person seeing a green sky and you seeing a blue one. If you still have problems with this then you need a book on psychology or neuroscience both of which will tell you colour is perception not a property of photons. I'm interested in why the Earth's tread in the light, and darkness outside the tread? The same light, the same eyes and the two events. Link to comment Share on other sites More sharing options...
Lilly Posted June 28, 2014 #36 Share Posted June 28, 2014 (edited) ... Your brain uses a tool to create an understanding of the world around you from those electrical impulses called your visual experience. Part of that is colour. If that doesn't clear it up for you consider a colour blind person seeing a green sky and you seeing a blue one. If you still have problems with this then you need a book on psychology or neuroscience both of which will tell you colour is perception not a property of photons. I understand what you're saying and you're quite correct regarding how humans perceive color. But, color is also a function of wavelength, frequency and energy of light. BTW, I never said that color perception was a property of photons (maybe someone else did but not me). There's a general confusion over light/dark/color here and I was trying to address the basics. For example, what most humans perceive as being 'blue' is a wavelength of 490 to 450 nm / frequency interval of 610 to 670 THz. Obviously, the brain is what's *seeing* this as being 'blue' and in someone that's color blind they would not be able to see 'blue' as others see 'blue'...no argument from me here. However, others (not you) don't appear to understand any of this. Edited June 28, 2014 by Lilly addition 1 Link to comment Share on other sites More sharing options...
Waspie_Dwarf Posted June 28, 2014 #37 Share Posted June 28, 2014 I dont think that the darkness is simply imagined either. Incidentally no one said it was imagined. The phrase I actually used was: Black is how the human brain interprets a total lack of detectable light. We don't "see" black. Black is what is there when there is nothing to see. Black is the absence of light in the same way that silence is the absence of sound. You don't see black in the same way that you don't hear silence. Link to comment Share on other sites More sharing options...
Waspie_Dwarf Posted June 28, 2014 #38 Share Posted June 28, 2014 (edited) So what you are saying is, if we could cut out a cube of space and bring it home that it would be filled with light ( even though we cant see it) and devoid of darkness ( even though thats all there is to see) lol No, that's not what I am saying. Your post is just some gibberish made up by someone that is so totally devoid of any knowledge of what light and dark are that they would say this: A star casts light not shadow. There is simply no point discussing it with you. Come back when you have caught up with the average six year old and I might just be able to simplify things to a level you can grasp. Until then I am giving up because I get a headache trying to think down to your level. Edited June 28, 2014 by Waspie_Dwarf Link to comment Share on other sites More sharing options...
taniwha Posted June 28, 2014 #39 Share Posted June 28, 2014 (edited) Incidentally no one said it was imagined. The phrase I actually used was: Black is the absence of light in the same way that silence is the absence of sound. You don't see black in the same way that you don't hear silence. On a slight side note, invisibility may be an interesting application of dark/light technologies. Researchers at the National University of Singapore have built a beam of darkness that can make objects invisible from a long distance away. This isnt the plot from some not-so-distant sci-fi movie: It really works. The beam of darkness can create a 3D region of invisibility — or “empty light capsule” as the researchers call it...that can hide macroscopic objects. The darkness beam, developed by Chao Wan and fellow researchers in Singapore, creates invisibility in a fundamentally different way to the invisibility cloaks that we usually cover on ExtremeTech. For the most part, the bleeding edge of invisibility cloak tech consists of a metamaterial enclosure that bends radiation microwaves, not light around an object. If we could build large, flexible, and lightweight invisibility cloaks of metamaterials, that’d be cool...but sadly, we are years and years away from such an invention. For now, metamaterial invisibility cloaks are mostly limited to a single dimension and a narrow range of radiation frequencies... and, as we’ve covered before, due to the cloak’s clunky physical dimensions, most of these cloaks actually increase the RF footprint of an object due to scattering of radiation that isntpicked up by the metamaterial. http://www.extremetech.com/extreme/172797-anti-resolution-darkness-ray-can-make-objects-invisible-from-a-distance Edited June 28, 2014 by taniwha Link to comment Share on other sites More sharing options...
Duke Wellington Posted June 28, 2014 #40 Share Posted June 28, 2014 I'm interested in why the Earth's tread in the light, and darkness outside the tread? The same light, the same eyes and the two events. Its not clear what you're trying to ask but I can answer for you if you're a little clearer. Link to comment Share on other sites More sharing options...
toast Posted June 28, 2014 #41 Share Posted June 28, 2014 Black is totally visible, you can point to it and say look there it is, you dont have to scratch your head and wonder where it is when you can see it. It seems that you need to get a small lesson on how the human eye get the interpretation of a color. Looking e.g.at a (red) tomato, it appears red to us. This effect is resulted by the fact that the tomatos surface absorbs all colors of the to us visible division of the electromagnetic spectrum except red (wavelength 640nm-780 nm). Same scenario for all other visible colors. Looking at a black surface it appears black to us because this surface absorbs all colors that are visible to us. Black itself isn`t a color, black is just a physical characteristic of a bodys surface, so, a neutral that we are able to see caused by the absence of colors. If our brain would ignore surfaces those absorb all colors, we would not see such surfaces. 1 Link to comment Share on other sites More sharing options...
Duke Wellington Posted June 28, 2014 #42 Share Posted June 28, 2014 I understand what you're saying and you're quite correct regarding how humans perceive color. But, color is also a function of wavelength, frequency and energy of light. BTW, I never said that color perception was a property of photons (maybe someone else did but not me). There's a general confusion over light/dark/color here and I was trying to address the basics. For example, what most humans perceive as being 'blue' is a wavelength of 490 to 450 nm / frequency interval of 610 to 670 THz. Obviously, the brain is what's *seeing* this as being 'blue' and in someone that's color blind they would not be able to see 'blue' as others see 'blue'...no argument from me here. However, others (not you) don't appear to understand any of this. The visual experience of colour can be traced back to its construction in the visual cortex. Its construction can be traced back to electrical signals being emitted from cells in the eyes. Those emissions can be traced back to photons of certain wavelengths being absorbed by those cells. If thats what you mean't by colour being a function of photons then you're correct. One is linked to the other through several stages even though the input and output are two completely different things (one is a physical property and the other is a perception). For those that can't grasp high-school physics, and I notice there's a lot of them, colour is to photons as the reading on the side of a thermomemeter is to heat. The reading isn't a property of hot water its a way of representing meaning. The thing you experience as colour is the minds representation of what the electrical signals it receives from the eyes mean. Nothing more. Link to comment Share on other sites More sharing options...
toast Posted June 28, 2014 #43 Share Posted June 28, 2014 I'm interested in why the Earth's tread in the light, and darkness outside the tread? The same light, the same eyes and the two events. What? Link to comment Share on other sites More sharing options...
Lilly Posted June 28, 2014 #44 Share Posted June 28, 2014 What? Exactly. 3 Link to comment Share on other sites More sharing options...
sepulchrave Posted June 29, 2014 #45 Share Posted June 29, 2014 To weigh in on the discussion between RabidMongoose and Lily, colour has a 1:1 mapping to wavelength (in the visible range of wavelengths). The distinction is therefore simply based on semantics: ``light has a wavelength which we perceive as colour'', or ``colour is the value our perception assigns to different wavelengths''. Does colour have any meaning independent of wavelength? I don't know if there is much value discussing this philosophical issue. Photons are strange little things and don't behave the way most people expect them to. They don't have intensity and they don't have colour. The only property they do have is wavelength. [Emphasis mine.] Photons do not always have a wavelength. The only definite properties a photon has is a mass of zero, a charge of zero, and a spin equal to the reduced Planck's constant. Every mechanical property; energy, momentum, frequency, wavelength, etc. is dependent on the circumstances, and no physical circumstance will allow any of these properties to be uniquely defined. Link to comment Share on other sites More sharing options...
Frank Merton Posted June 29, 2014 #46 Share Posted June 29, 2014 Actually as I understand it the brain assigns colors to various wavelengths of impinging light based on all sorts of things in addition, such as intensity, nearby colors, contrasts, focus, rods or cones, and so on. The brain very much censors what we "see" in order to make our understanding of what is out there easier. Link to comment Share on other sites More sharing options...
Weitter Duckss Posted June 29, 2014 Author #47 Share Posted June 29, 2014 Its not clear what you're trying to ask but I can answer for you if you're a little clearer. The light coming from the sun. If we use our eyes,why we see the light within tread and outside the tread does not (from the ISS)? Link to comment Share on other sites More sharing options...
sepulchrave Posted June 29, 2014 #48 Share Posted June 29, 2014 The light coming from the sun. If we use our eyes,why we see the light within tread and outside the tread does not (from the ISS)? If you have good eyes, I suppose you could see light from the ISS. Why don't you try a fun experiment? Take an ordinary flashlight, stick it right up in your eye, and turn it on and note how bright it appears. Give the flashlight to a friend, have them go to the end of a football field, and turn it on and note how bright it appears. Rent a spotlight, place it at the same end of the football field, turn it on, and note how bright it appears. After legally disavowing me of any responsibility for any loss of vision, stick the same spotlight right up in your eye, turn it on, and note how bright it appears. Then see if you can formulate a theory regarding the perceived brightness of an incoherent, pseudo-isotropic light source in relation to the intensity of the source and the viewer's proximity to that source. Link to comment Share on other sites More sharing options...
Duke Wellington Posted June 29, 2014 #49 Share Posted June 29, 2014 (edited) To weigh in on the discussion between RabidMongoose and Lily, colour has a 1:1 mapping to wavelength (in the visible range of wavelengths). The distinction is therefore simply based on semantics: ``light has a wavelength which we perceive as colour'', or ``colour is the value our perception assigns to different wavelengths''. Does colour have any meaning independent of wavelength? I don't know if there is much value discussing this philosophical issue. [Emphasis mine.] Photons do not always have a wavelength. The only definite properties a photon has is a mass of zero, a charge of zero, and a spin equal to the reduced Planck's constant. Every mechanical property; energy, momentum, frequency, wavelength, etc. is dependent on the circumstances, and no physical circumstance will allow any of these properties to be uniquely defined. Thats okay as I'm aware of that too. I think you'll have a problem though with those who can't get past colour being a perception when it comes to convincing them that the properties of photons aren't quite as real as they think that they are. They dont understand that what exists or what is real is relative to their circumstances and doesnt have to exist for someone else in a different set of circumstances relative to them. Edited June 29, 2014 by RabidMongoose Link to comment Share on other sites More sharing options...
Lilly Posted June 29, 2014 #50 Share Posted June 29, 2014 Why don't you try a fun experiment? It never ceases to amaze me how some people simply have never observed that which is obvious (painfully obvious no less). 1 Link to comment Share on other sites More sharing options...
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