pzkpfw Posted March 24, 2017 Share Posted March 24, 2017 What do you mean by in a way the darkness is whats already there? You won't see something, unless there's something there to see, that's generating light, or reflecting light generated by something else, ... and there's enough of that light reaching your eyes. Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 You won't see something, unless there's something there to see, that's generating light, or reflecting light generated by something else, ... and there's enough of that light reaching your eyes. Are you trying to say that if there was no objects reflecting light we would observe relatively, it to be dark,? as in earlier discussion between the stars. Link to comment Share on other sites More sharing options...
pzkpfw Posted March 25, 2017 Share Posted March 25, 2017 Are you trying to say that if there was no objects reflecting light we would observe relatively, it to be dark,? as in earlier discussion between the stars. That's over simplifying. Link to comment Share on other sites More sharing options...
StringJunky Posted March 25, 2017 Share Posted March 25, 2017 (edited) Are you trying to say that if there was no objects reflecting light we would observe relatively, it to be dark,? as in earlier discussion between the stars. Yes, you won't see a narrow light beam in a vacuum that was passing in front of you, across your range of vision. It needs to scatter off something to pass into your pupils, then you'll see the object it scattered off. Edited March 25, 2017 by StringJunky Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 (edited) That's over simplifying. Fascinating, so in space we observe matter that is illuminated in the dark? Edited March 25, 2017 by JohnLesser Link to comment Share on other sites More sharing options...
pzkpfw Posted March 25, 2017 Share Posted March 25, 2017 Fascinating, so in space we observe matter that is illuminated in the dark? Do you know what "oversimplifying" means? But anyway, ever seen the Moon? Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 Yes, you won't see a narrow light beam in a vacuum that was passing in front of you, across your range of vision. It needs to scatter off something to pass into your pupils, then you'll see the object it scattered off. This narrow beam of light having no wavelength? Do you know what "oversimplifying" means? But anyway, ever seen the Moon? Yes i have seen the moon but i am not sure how you have answered my question. My interpretation of the information received in this thread is that you have practically told me that we see things that ''glow'' in the dark.huh? Link to comment Share on other sites More sharing options...
StringJunky Posted March 25, 2017 Share Posted March 25, 2017 (edited) This narrow beam of light having no wavelength? Visible spectrum. Unless the light reflects off something, you won't see any light. When you shine a torch up in the air, some of the light is reflecting back at you from the air molecules, water molecules and other particles floating around, hence, you see a beam. Edited March 25, 2017 by StringJunky Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 Visible spectrum. Unless the light reflects off something, you won't see any light. When you shine a torch up in the air, some of the light is reflecting back at you from the air molecules, water molecules and other particles floating around, hence, you see a beam. yes we only see visible light in the range of 400nm-700nm wave-length. Link to comment Share on other sites More sharing options...
StringJunky Posted March 25, 2017 Share Posted March 25, 2017 (edited) yes we only see visible light in the range of 400nm-700nm wave-length. Yes, and you won't see it's effect until it reflects off something, passes into your eyes and excites the rods and cones in your retina. If no photons are exciting them, how can you see anything but dark? Edited March 25, 2017 by StringJunky Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 (edited) Yes, and you won't see it's effect until it reflects off something, passes into your eyes and excites the rods and cones in your retina. Interesting , so the wave-length of invisible light is longer than 700nm? If no photons are exciting them, how can you see anything but dark? true Edited March 25, 2017 by JohnLesser Link to comment Share on other sites More sharing options...
StringJunky Posted March 25, 2017 Share Posted March 25, 2017 Interesting , so the wave-length of invisible light is longer than 700nm? true Yes and the same less than 400nm But I chose the visible spectrum because we have the potential to see it when it reflects off something. Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 Yes and the same less than 400nm But I chose the visible spectrum because we have the potential to see it when it reflects off something. You say the same less than 400nm, I would of thought that would be more visible nearing to a black body? Link to comment Share on other sites More sharing options...
StringJunky Posted March 25, 2017 Share Posted March 25, 2017 You say the same less than 400nm, I would of thought that would be more visible nearing to a black body? No, our eyes don't have the receptors to work below 400nm. 1 Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 (edited) No, our eyes don't have the receptors to work below 400nm. ok, The invisible light between the distant stars, is that light a longer or a shorter wave-length than 700nm? Edited March 25, 2017 by JohnLesser Link to comment Share on other sites More sharing options...
StringJunky Posted March 25, 2017 Share Posted March 25, 2017 ok, The invisible light between the distant stars, is that light a longer or a shorter wave-length than 700nm? Both. The whole gamut of possible wavelengths. Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 Both. The whole gamut of possible wavelengths. What I find interesting is that light exerts a force, we have already mentioned in this thread space is made of ''nothing''. Space offers no permeability or permitivity to have any opposing force to light. I assume there is nothing of space that could compress light to be a wave. Why do we not view light passing through space in being decompressed and a linearity until opposite force/obstruction is in the way? Link to comment Share on other sites More sharing options...
Moontanman Posted March 25, 2017 Share Posted March 25, 2017 What I find interesting is that light exerts a force, we have already mentioned in this thread space is made of ''nothing''. Space offers no permeability or permitivity to have any opposing force to light. I assume there is nothing of space that could compress light to be a wave. Why do we not view light passing through space in being decompressed and a linearity until opposite force/obstruction is in the way? I am not real sure space is made of nothing, I am sure that Lawrence Krauss would disagree. Can you give us a citation to back up your assertion that space is made of nothing? Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 (edited) I am not real sure space is made of nothing, I am sure that Lawrence Krauss would disagree. Can you give us a citation to back up your assertion that space is made of nothing? I could not give a citation. Space itself ''beyond'' matter has no physicality and I do not believe it has been proven otherwise, so therefore until any such proof, it remains made of nothing. Saying otherwise is at best psuedo. Edited March 25, 2017 by JohnLesser Link to comment Share on other sites More sharing options...
StringJunky Posted March 25, 2017 Share Posted March 25, 2017 I could not give a citation. Space itself ''beyond'' matter has no physicality and I do not believe it has been proven otherwise, so therefore until any such proof, it remains made of nothing. Saying otherwise is at best psuedo. If we put a ruler in space we can measure it. If we can measure it, it is physical. I am defining physical as: That which pertains to physics. Physicists measure things and study their behaviour. Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 (edited) If we put a ruler in space we can measure it. If we can measure it, it is physical. I am defining physical as: That which pertains to physics. Physicists measure things and study their behaviour. We can measure a length of space but how does that imply space itself is made of anything physical? We can easily examine space as it ''surrounds'' all of us. If we was to remove all the matter from a small volume of that space then certainty all that is left is a volume of empty space , made of nothing? Notions such as a Higg's field being ''occupants'' of space . Space in my opinion is not relative to anything because realistically we do not observe any change of the state of space. We observe change in the state of matter from one increment of time to the next. Of course with time there is many factors to consider such as relativistic effects and time dilation, but all the states of matter have some form of physicality unlike our observations of just plain old space. I would assume that things age and all that is change, is relative to space and only comparable too and because of space? Edited March 25, 2017 by JohnLesser Link to comment Share on other sites More sharing options...
Strange Posted March 25, 2017 Share Posted March 25, 2017 Space offers no permeability or permitivity to have any opposing force to light. The speed of light is defined by the permeability and permittivity of space http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elefie.html#c4 Link to comment Share on other sites More sharing options...
JohnLesser Posted March 25, 2017 Author Share Posted March 25, 2017 (edited) The speed of light is defined by the permeability and permittivity of space http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elefie.html#c4 It looks like a zero value to me? ε0 and magnetic permeability μ0 of free space Edited March 25, 2017 by JohnLesser Link to comment Share on other sites More sharing options...
mistermack Posted March 25, 2017 Share Posted March 25, 2017 I could not give a citation. Space itself ''beyond'' matter has no physicality and I do not believe it has been proven otherwise, so therefore until any such proof, it remains made of nothing. Saying otherwise is at best psuedo. "According to present-day understanding of what is called the vacuum state or the quantum vacuum, it is "by no means a simple empty space",[1] and again: "it is a mistake to think of any physical vacuum as some absolutely empty void."[2] According to quantum mechanics, the vacuum state is not truly empty but instead contains fleeting electromagnetic waves and particles that pop into and out of existence.[3][4][5]" https://en.wikipedia.org/wiki/Vacuum_state 1 Link to comment Share on other sites More sharing options...
Strange Posted March 25, 2017 Share Posted March 25, 2017 It looks like a zero value to me? The values are given here: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elefie.html#c3 Link to comment Share on other sites More sharing options...
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