Absorbtion,reflection,and emission.

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SUMMARY

The discussion focuses on the principles of absorption, reflection, and emission of electromagnetic radiation, particularly in relation to human bodies and specific examples like Smurfs. It confirms that humans primarily emit infrared radiation, as described by Wien's Law, while selectively absorbing and reflecting components of visible light. The conversation clarifies that emission originates from an object's thermal energy, whereas reflection occurs when light from another source is involved. Additionally, it highlights that only certain frequencies can be absorbed, leading to electronic or phononic excitations, while others are reflected.

PREREQUISITES
  • Understanding of Wien's Law and its application to thermal radiation
  • Knowledge of electromagnetic radiation and its spectrum
  • Familiarity with concepts of absorption and reflection in physics
  • Basic principles of particle physics, particularly regarding photons
NEXT STEPS
  • Research the applications of Wien's Law in thermal imaging technologies
  • Explore the electromagnetic spectrum and its interaction with different materials
  • Study the mechanisms of electronic and phononic excitations in materials
  • Investigate the differences between absorption, reflection, and emission in various contexts
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Students and professionals in physics, material science, and engineering, particularly those interested in the interactions of light with matter and thermal radiation principles.

LogicalAcid
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I want to see if I understand these rules correctly. Us humans emit mainly in the infrared, that can be described by wiens law, but when visible radiation falls upon us, our body absorbs some part of the white light, but reflects whatever it doesn't. Smurf's for example reflect the blue part of visible radiation, while absorbing all other parts of the visible spectra.

And if emission is when an object emits electromagnetic radiation, isn't that the same as reflection? Or are they different? Is emission when it comes from the objects own thermal energy, and reflection when it comes from another object emitting it? And why is it that particles can be reflected, instead of completely absorbed and emitted?
 
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LogicalAcid said:
Is emission when it comes from the objects own thermal energy, and reflection when it comes from another object emitting it?
yes
And why is it that particles can be reflected, instead of completely absorbed and emitted?
by particles, do you mean photons?
Light of only certain frequencies can be absorbed by an object, such as the ones that cause electronics excitations, phononic (vibrational) excitations, ... These may later be emitted. The other frequencies just get reflected.
 

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