Why do black bodies emit light at all wavelengths when heated?

In summary, black bodies have a continuous emission spectrum because they contain charged particles that are constantly moving and emitting light due to thermal energy. This is different from the discrete emission spectrum of elements, which is caused by specific electron energy levels.
  • #1
Niko Bellic
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Why do "black bodies" emit light at all wavelengths when heated?

Light emitted from an object is made of photons that are emitted when electrons drop into lower energy states. And there are only certain energy states in an atom that electrons can occupy, so only certain wavelengths (aka. energies) of light are produced by specific atoms.
This is why the emission spectrum of elements is characterized by discrete lines at specific wavelengths.

However, black bodies have a continuous emission spectra. Why are black bodies different --- do they not have finite electron energy levels?

Thank you. This is my first post. I'm glad to be on here! :)
 
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  • #2


Thermal emission is different from the stimulated emission you described.
In a thermal source the charged particles are moving because of the thermal energy, moving (or at least accelerating) charges emit light
 

Related to Why do black bodies emit light at all wavelengths when heated?

1. Why do black bodies emit light at all wavelengths when heated?

Black bodies emit light at all wavelengths when heated because they are perfect absorbers and emitters of electromagnetic radiation. This means that they absorb all the incoming radiation and re-emit it at all wavelengths, resulting in a continuous spectrum of light.

2. What is the significance of a black body emitting light at all wavelengths?

The fact that black bodies emit light at all wavelengths is significant because it provides a standard reference for studying the properties of electromagnetic radiation. It also helps to explain the observed spectra of stars and other celestial bodies.

3. How does the temperature of a black body affect the wavelengths of light it emits?

The temperature of a black body directly affects the wavelengths of light it emits. As the temperature increases, the peak wavelength of emitted light shifts towards the shorter (blue) end of the spectrum. This is known as Wien's displacement law.

4. What is the relationship between the temperature of a black body and the amount of light it emits?

The amount of light emitted by a black body is directly proportional to its temperature. This relationship is described by the Stefan-Boltzmann law, which states that the total energy emitted by a black body is proportional to the fourth power of its temperature.

5. Can black bodies emit light at specific wavelengths?

No, black bodies cannot emit light at specific wavelengths. As perfect absorbers and emitters, they emit a continuous spectrum of light at all wavelengths when heated. However, by manipulating the temperature of a black body, we can control the dominant wavelength of emitted light.

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