Infrared waves are widely used for quick heating objects, but a quick look at electromagnetic spectrum astonished me and raised a question that how come an infrared wave with lower energy compared to visible light is able to heat objects.Is there anything here related to resonance …??
[Physics] Infrared Vs Visible Light
visible-light
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As a general rule there are three mechanisms by which molecules absorb light:
- Electronic transitions - visible/uv wavelengths
- Vibrational transitions - infra-red wavelengths
- Rotational transitions - microwave wavelengths
In solids you don't often get rotational spectra because the molecules usually aren't free to move without interacting with the lattice, so you tend to get electronic transitions in the uv and vibrational transitions in the IR. It's probably not coincidence that there is frequently no absorption at visible wavelengths because we wouldn't have evolved eyes if there was.
In isolated molecules you get nice sharp vibrational transitions (with rotational structure as well) but in solids the interaction with the lattice tends to broaden out the absorption lines. You'll find numerous articles on IR spectroscopy of silica glass, for example this one though it's behind a paywall. As DumpsterDoofus comments, you get absorption due to hydroxyl and/or water, but you also get absorption due to various stretching modes of the Si-O-Si lattice.
It sounds like you know some of the most important summary points about blackbody radiation, but here is a reference on the subject, since I will be talking almost entirely about blackbody radiation: https://en.wikipedia.org/wiki/Black-body_radiation
Given any temperature, there is a certain emission spectrum (see https://en.wikipedia.org/wiki/Planck%27s_law) describing the mixture of photons which a body at that temperature emits. As you already noted, the peak frequency of this spectrum increases as the temperature increases. It is also of interest to note that an increase in temperature increases photon emission at ALL frequencies, not just higher frequencies.
The short form answer to your question is that we live in on Earth, where temperatures tend to be in the 200-400K range. Even a campfire doesn't make it much above 1500K. At all of these temperatures (yes, including the campfire) the VAST majority of the energy radiated is in the infrared range. If you put a filter between yourself and a campfire which absorbed all visible light and transmitted all infrared light, you would feel just as warm. So it is natural for us to associate infrared radiation with heat. The sun is the only everyday example of something that warms us noticeably with visible light, and sunlight already holds its own unique place in the human experience. Sunlight feels warm. A physicist can get out sensitive instruments and observe that in fact all light warms us slightly, but as far as what we can feel with our own nerves goes, it is only infrared and sunlight that seem warm.
If we were plasma beings that inhabited the core of the sun, perhaps we would associate visible light (or some energetic subatomic particle or other...) with the transmission of thermal energy, but we aren't and we don't.
In the end, all light transmits energy, and heat is just energy in the form of atoms exercising their degrees of freedom. So there is no clear cut distinction between the way infrared radiation interacts with heat and the way any other radiation does. But over most of the wide range of commonly studied environments, heat is mostly ratiaded as infrared photons. Thus the association.
Regarding your thought about incandescent lights vs more efficient alternatives, we replaced our 60-100 Watt bulbs with 7-20 Watt bulbs, so they really don't warm us up anywhere near as much as the old ones. If we had replaced the bulbs with equivalent wattages, then your thought would be correct, but we would be blinded by our lamps!
Best Answer
When you say:
I'm guessing you're referring to the photon energy:
$$ E = h\nu $$
Visible light has a higher frequency than IR light, so the energy per photon of visible light is higher than IR light. However this is not related to the energy carried by the wave. The power transmitted by a wave is the energy per photon multipled by the number of photons per second, and we can adjust the number of photons per second simply by adjusting the intensity of the radiation. So a high intensity IR wave can transmit more power than a low intensity visible wave.
We tend to use IR for heating things simply because it's easier to generate high intensity IR than high intensity light. Many of the radiation sources we use approximate black bodies, and the peak frequency of black body radiation is proportional to the black body temperature. So to generate visible light requires a considerably higher temperature than to generate IR.