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  1. #1 light 
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    greetings, i'am supporting the theory that two forms of light exsist.
    man made light, and natural light. the gist of the theory is that man made light may very well travel, but natural light does not


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  3. #2 Re: light 
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    Quote Originally Posted by curious1
    greetings, i'am supporting the theory that two forms of light exsist.
    man made light, and natural light. the gist of the theory is that man made light may very well travel, but natural light does not
    I'm confused. Natural light does not travel? So who made the Sun?


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    I am wondering if the question refers, on one hand, to the sensation of light that we see around us - such as the light in the sky - and, on the other, the light that we believe travels from a lamp to an object that it illuminates.

    They are, of course, aspects on the same thing. However, it is interesting to note that there was a time when some people believed that "seeing" involved something travelling from the eye to what was seen.
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  5. #4 Re: light 
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    Quote Originally Posted by curious1
    greetings, i'am supporting the theory that two forms of light exsist.
    man made light, and natural light. the gist of the theory is that man made light may very well travel, but natural light does not
    Light has a definition. Whether man creates the light or it is created by something other htan man has no bearing on its properties.

    Light, by its definition, varies in color by its radiant frequency, intensity by its volume of photons, and coherence by columniation of its photon or wave components. Light has no other properties to vary between what man caused versus what non-man caused.

    The photons are merely electric waves partly chasing their own tail yielding a partially particle effect as well as a wave effect.

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  6. #5 re; light 
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    i disagress, Natural light differs from man made light in that it contains Heat as a primary element. i.e. The sun, Fire. this heat depending on its degree illuminates the area of its influence thereby making its light visible and perhaps giving the false impression of travel. a star in the night sky depending on its heat ratio illuminates its area of influence thereby making it visible, what we see upon observation of this star is not light traveling but illumination depending on the degree of heat at the source.

    man made light does travel it is beamish and have the intent of lighting a darken area, this intent may have contributed it to having the sameness with natural light. however man made light has heat as a by product, not a elemental essential there fore it illuminates only the area it is directed thus given it travel capacity.

    elemental heat is the variable that seperates natural light from man made light, shine your flashlight and one can see light travel from your hand to say a nearby wall in direction. observe the star or fire and you can see light illuminate the area of its influence due to the degree of heat it contains. no travel is involved even if you see it from a great distance no yravel is involved. you merely see elemental heat having a influence on a area.
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    When one planet moves between the sun and another planet, the planet that's closer to the sun doesn't immediately cast a shadow over the planet that's further away - there is a delay. That seems to prove that "natural" light does indeed travel.
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  8. #7 Re: re; light 
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    Quote Originally Posted by curious1
    i disagress, Natural light differs from man made light in that it contains Heat as a primary element. ...
    I think you are greatly misunderstanding light and heat.

    Heat has two forms, kinetic and radiant. Radiant heat is light but just in the frequency range below what your eyes can see. Kinetic heat often, but not always, causes radiant light from the heat source.

    The radiant heat travels exactly like light does because it actually is light. Because radiant heat is a lower frequency, it bends a little less than visible light and can go through some things that visible light reflects off of.

    The light that you see from a star is almost entirely from the source of kinetic heat producing both radiant heat as well as visible light.

    The heated objects, because they are heated, become a heat source and radiates a degree of radiant heat light that can be seen with proper equipment. A heated object cannot produce visible light unless it is very heated to the point of glowing.

    The light that you see coming from lighted objects is reflected light from another source.
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  9. #8 Re: re; light 
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    Quote Originally Posted by curious1
    i disagress, Natural light differs from man made light in that it contains Heat as a primary element. i.e. The sun, Fire. this heat depending on its degree illuminates the area of its influence thereby making its light visible and perhaps giving the false impression of travel. a star in the night sky depending on its heat ratio illuminates its area of influence thereby making it visible, what we see upon observation of this star is not light traveling but illumination depending on the degree of heat at the source.

    man made light does travel it is beamish and have the intent of lighting a darken area, this intent may have contributed it to having the sameness with natural light. however man made light has heat as a by product, not a elemental essential there fore it illuminates only the area it is directed thus given it travel capacity.

    elemental heat is the variable that seperates natural light from man made light, shine your flashlight and one can see light travel from your hand to say a nearby wall in direction. observe the star or fire and you can see light illuminate the area of its influence due to the degree of heat it contains. no travel is involved even if you see it from a great distance no yravel is involved. you merely see elemental heat having a influence on a area.
    The first measurement of the speed of light was done with "natural" light, through the observations of the moon Jovian Io by the Danish astronomer, Ole Römer. He noted that the measured time between the eclipses of this moon varied periodically. The variation matched the varying distance between the Earth and Jupiter at the time of observation. IOW, at times the light from IO had to travel longer distances and arrived later than at other times. At other times, when the Earth and Jupiter were closer, the light took less time to traverse the distance. This varying time delay is what caused the variation between the observed of the eclipses.

    As far as the flashlight and fire goes, the flasshlight projects a beam simply because it has a shaped mirror behind it. You could place a shaped mirror behind the fire, and it too would produce a beam. (in fact, early lighthouses used flames to produce their light and directed this light into a beam by mirrors and lenses.)
    In fact, one could produce a beam from the fire without any mirrors or lenses, just by enclosing it and poking a hole in the enclosure, a beam of light will emit from the hole.

    On the other hand, I could replace the fire with a bare light bulb and it too will illuminate the area, just like the fire did.

    As far as your "heat" argument goes, I could put a thick glass plate in front of the fire that will block its heat, yet the fire will still illuminate everything on the far side of the glass, just as if the glass were not there.


    I'm sorry, but your hypotheisis on a difference between "natural" and "manmade" light is simply not very well thought out.
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  10. #9  
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    Just to clarify one point that frequently comes up in discussions like this: Light is defined as electromagnetic waves within the visible frequency spectrum.

    Hence, expressions like "light is heat", or "heat is light", are nonsense by definition. If you can't see it, it's not light. If you can see it, it's not heat. Expressions like "visible light" are redundant (there is no "invisible light" by definition). Never mind that colloquial language tends to adopt non-scientific terminology. We're trying to talk science here, so let's keep it precise.

    The difference between the light emitted by natural or artificial sources could be in intensity or frequency spectrum. For example, the sodium vapor lamps used in street lanterns emit light in a very narrow spectrum (almost a single frequency).

    In addition, coherence/interference can be very different in some artificial and natural emissions, e.g. laser compared to sunlight. This might be what curious1 is talking about, because it affects "travel".
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    Quote Originally Posted by M
    Just to clarify one point that frequently comes up in discussions like this: Light is defined as electromagnetic waves within the visible frequency spectrum.
    Yeah, but even professional scientists and engineers routinely use the word "light" to refer to any part of the electromagnetic spectrum. Hence the common terms “infrared light” and “ultraviolet light” that you can easily find in science journals.
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  12. #11  
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    Quote Originally Posted by M
    Just to clarify one point that frequently comes up in discussions like this: Light is defined as electromagnetic waves within the visible frequency spectrum.

    Hence, expressions like "light is heat", or "heat is light", are nonsense by definition. If you can't see it, it's not light. If you can see it, it's not heat. Expressions like "visible light" are redundant (there is no "invisible light" by definition). Never mind that colloquial language tends to adopt non-scientific terminology. We're trying to talk science here, so let's keep it precise.

    The difference between the light emitted by natural or artificial sources could be in intensity or frequency spectrum. For example, the sodium vapor lamps used in street lanterns emit light in a very narrow spectrum (almost a single frequency).

    In addition, coherence/interference can be very different in some artificial and natural emissions, e.g. laser compared to sunlight. This might be what curious1 is talking about, because it affects "travel".
    From Merriam Webster online; http://www.m-w.com/dictionary/light

    Main Entry: 1light
    Pronunciation: 'lIt
    Function: noun
    Etymology: Middle English, from Old English lEoht; akin to Old High German lioht light, Latin luc-, lux light, lucEre to shine, Greek leukos white
    1 a : something that makes vision possible b : the sensation aroused by stimulation of the visual receptors c : electromagnetic radiation of any wavelength and traveling in a vacuum with a speed of about 186,281 miles (300,000 kilometers) per second; specifically : such radiation that is visible to the human eye
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  13. #12  
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    Quote Originally Posted by Scifor Refugee
    Quote Originally Posted by M
    Just to clarify one point that frequently comes up in discussions like this: Light is defined as electromagnetic waves within the visible frequency spectrum.
    Yeah, but even professional scientists and engineers routinely use the word "light" to refer to any part of the electromagnetic spectrum. Hence the common terms “infrared light” and “ultraviolet light” that you can easily find in science journals.
    Which can readily be seen, for example, here
    http://adsabs.harvard.edu/cgi-bin/np...t%22&version=1

    This search, for visible light, on the Smithsonian/NASA astrophysics data systems returned 3814 hits. Thus the term is in common use outside and inside the science community.
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