Infrared heats a body but UV heats less

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Discussion Overview

The discussion centers on the comparative heating effects of infrared (IR) and ultraviolet (UV) radiation on bodies with identical properties and temperatures. Participants explore the implications of energy per photon, intensity, and absorption characteristics of different electromagnetic waves.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant claims that IR radiation results in a greater temperature increase in a body compared to UV radiation, despite UV having higher energy per photon due to its higher frequency.
  • Another participant succinctly states that IR heats while UV burns, suggesting a qualitative difference in their effects.
  • A participant explains that at the same intensity, UV light has fewer photons because of its higher energy per photon, complicating the comparison of heating effects.
  • One participant reiterates the initial claim about IR heating more than UV and clarifies that while intensity refers to total energy, the number of photons differs between the two types of radiation, leading to different absorption rates by the body.
  • There is a conditional statement that if a body absorbed more UV than IR, it would be heated more by the UV.

Areas of Agreement / Disagreement

Participants express differing views on the heating effects of IR versus UV radiation, with no consensus reached on the primary reasons for the observed differences in temperature increase.

Contextual Notes

The discussion does not resolve the assumptions about the specific properties of the bodies involved or the exact conditions under which the heating is measured.

Multiverse
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Infrared heats a body but UV heats less!

If we consider two bodies of indentical properties (and temperature) and we apply radiation on them with different EM wave ,One with Infrared and the other with UV ray,we find that the body exposed by IR has more temperature increase with respect to other...
The Problem is UV has higher freqency and thus have more energy having same intensity ,so it should heat more.
 
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IR heats. UV burns.
 


With the same intensity, the UV light has fewer photons, as the energy per photon is higher and intensity is usually defined as energy per time per area.

Without any knowledge about your body, it is impossible to say which photons heat it more.
 


Multiverse said:
If we consider two bodies of indentical properties (and temperature) and we apply radiation on them with different EM wave ,One with Infrared and the other with UV ray,we find that the body exposed by IR has more temperature increase with respect to other...
The Problem is UV has higher freqency and thus have more energy having same intensity ,so it should heat more.

Same intensity =/= same number of photons. Same intensity = same total energy.

So, your body absorbs IR more than UV, and thus is heated more by the IR than the UV. There is no issue here.

(If, on the other hand, it absorbed more UV than IR, it would be heated more by the UV.)
 

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