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Blue light may have more energy per photon than red light, but the rate that energy is being deposited on a thermometer depends on the power spectrum of the particular light beam. For example, a big bright red lightbulb can transfer a lot more energy per second than a tiny blue one, regardless of the wavelengths involved. In Herschel's case, he was using ...


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This thermometer is sensitive in a band 5.5um-14um. The equation (2) (I think) shows your black-body spectrum and the IR-th integrates the intensity in the above range. Normally, such a probe should also measure the ambient temperature and it should know the emissivity $\epsilon$ value of the material you point at, to properly calculate the temperature. ...


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Not all light bulbs are thermal emitters. Fluorescent lights do not use incandescence, hence they would not emit an equal spectrum to an incandescent source with an identical maximal light frequency. But in general yes objects do concurrently emit a whole spectrum of waves based on their temperature, regardless of whether their light is visible to us.


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For light bulbs and other thermal emitters this is definitely true. Their emission follows the black body spectrum (if you neglect absorption due to the glass container). If you want to be picky: Any device, which is operated above 0 K (which applies to all devices) emit thermal radiation according to their temperature. This is not directly related with the ...


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As @john-rennie have state out. Shorter wavelength tend to absorb and heat the outer layer of object. Microwave using long wavelength to penetrate to inside and also it use the property of dipole moment of water molecule to heat things, not directly heat by let object absorb energy If we just use short wave then you can only get burnt outside and raw inside ...


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In microwave ovens what matters is how much energy the radiation carries and how that energy is absorbed by the food. Visible light and IR are rapidly absorbed by most foods, so they would only heat the outer layer of the food. You'd get food with the outside carbonised and the inside raw. Microwaves are far less strongly absorbed by foods, so they ...



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