What Does Black Light Do to a Blackbody?

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Discussion Overview

The discussion revolves around the concept of "black light" and its interaction with a blackbody. Participants explore the nature of black light, its definition, and the implications of wave interference in light phenomena, touching on both classical and quantum perspectives.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant suggests that black light is created when two waves of light with opposite phases intermingled, questioning what happens when this light interacts with a blackbody.
  • Another participant counters that black light is commonly understood as ultraviolet light, which has a shorter wavelength than visible light and is not detectable by humans.
  • A participant shares a speculative idea about wave cancellation, proposing that if two waves of opposite phase could cancel each other out, it might imply a way to create light energy from nothing, although they later dismiss this notion.
  • A reply emphasizes the importance of energy conservation in wave interference, explaining that while cancellation can occur in some regions, it is accompanied by reinforcement in others, and that wave interference should not be viewed in terms of individual photons cancelling each other.
  • One participant reflects on their previous misunderstanding of black light, acknowledging that they had been misinformed about its nature.

Areas of Agreement / Disagreement

Participants express differing views on the definition of black light and its properties, with no consensus reached on the implications of wave interference or the nature of black light itself.

Contextual Notes

Some claims rely on assumptions about wave behavior and definitions of light, and the discussion includes unresolved questions about the interaction between black light and blackbodies.

philrainey
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if a wave of light intermingles with another the same but of opposite phrase I believe you get what is called black light. If the black light hits a blackbody what happens? does any radiation energy heat up the black body?
 
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philrainey said:
if a wave of light intermingles with another the same but of opposite phrase I believe you get what is called black light.

No. Black light is merely a common name for ultraviolet light.

http://en.wikipedia.org/wiki/Black_light

Ultraviolet light is simply shorter wavelength than violet light. Humans can't see it, though some other creatures (such as bees) can.
 
Oh I had this hairy fairy idea (thinking of light as waves) That two waves of opposite phrase traveling in the same vector kind of canceled each other out. Maybe like add to zero. I thought as the universe is suppose to add to zero if the opposite of something is added to something then that something would return to zero. Then I went on with my notion and thought maybe that could be reversiable and one could in theory create light energy from nothing. Never mind.
 
philrainey wrote in:
#1:
if a wave of light intermingles with another the same but of opposite phrase I believe you get what is called black light. If the black light hits a blackbody what happens? does any radiation energy heat up the black body?
#3:
Oh I had this hairy fairy idea (thinking of light as waves) That two waves of opposite phrase traveling in the same vector kind of canceled each other out. Maybe like add to zero. I thought as the universe is suppose to add to zero if the opposite of something is added to something then that something would return to zero. Then I went on with my notion and thought maybe that could be reversiable and one could in theory create light energy from nothing. Never mind.
philrainey - please carefully consider which sectioin in PF your queries truly belong. Both this one and previous one 'Bending radiation' are not really QM but more of a classical/general physics nature.

Wave interference is real enough but is believed to always obey total conservation of energy. Some examples are the light and dark interference fringes seen in double-slit experiments (classical optics or QM), or scattering of waves at waveguide junctions and obstacles, see e.g. http://en.wikipedia.org/wiki/Interference_(wave_propagation). The basic idea is such scattering/interference is 'unitary' - net input = net output. Which means cancellation in some regions is accompanied by reinforcement elsewhere and/or at other times ('beat' phenomena). One doesn't think of wave interference in terms of individual field quanta (photons) cancelling each other, but is really a collective phenomenon that emerges from the summed behaviour of many individual quanta.
 
Last edited:
for years I thought black light was light waves that canceled each other out, I really got it wrong. I think somebody at college told me that and I have believed it ever since. Well we have sorted that false notion out.
 

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