From what I understand, when an object has a certain temperature, its atoms vibrate and this atomic vibration accelerates the electrically charged particles and this generates infrared radiation.
To generate infrared radiation, it is therefore necessary to accelerate electrically charged particles, but since atoms are electrically neutral, how can their acceleration generate infrared radiation?
It is not the atoms composing an object that emit radiation, called black body radiation, it is changes in the quantized energy levels within a solid or a liquid that will be emitted as photons.
From what I understand, when an object has a certain temperature, its atoms vibrate
Its atoms change energy levels in the lattice of the solid and this generates statistically what is called black body radiation, which at room temperatures is mostly in the infrared. Maybe the answers to this question will help .
I would taks H atom as an example. One electron and one proton. There are a number of discrete energy levels (negative energies since the electron is bound to the proton). Normally the electron is in the lowest state of energy called the ground state which is -13.6 eV. If the electron due to collisions with other atoms or some other reason such as temperature goes to a higher energy then it cant stay there for long it comes back to its ground state. Depending on the difference of two levels the E.M. radiation is emmited. This is typically the case of all atoms. IR visibile UV X-rays etc radiations can therefore be emmitted.
This can be explained by fundamental principles of Light-Matter Interaction and Absorption & Emission of Radiation.
The electrons/atoms inside any conducting volume boundary oscillate due to thermal motion/heat energy. These vibrations can cause the electrons in the atoms to move slightly from their normal positions, giving rise to electric dipole moments which generates electro-magnetic standing waves inside that cavity.
From the Coulomb’s force law between two electric charges and Ampere’s force law (force per unit length) of magnetic induction, we can find the energy of a standing-wave electromagnetic field and the spectral energy density
The standing waves satisfying the boundary conditions as a function of frequency with each wave having an energy can be explained bythe spectral distribution of energy density by Rayleigh-Jeans black-body energy density distribution and Planck black-body energy density distribution.
The energy flow between the atoms in the cavity (e.g. a two-level atom) and the field modes of the cavity are described by Einstein rate equations (also Einstein A and B coefficients) that determines the resonant stimulated absorption and emission, E2−E1 = hω_0, with the rates proportional to the spectral energy density ρ_ω of the cavity modes. and eventually wavelength of electromagnetic radiation emitted by an atom.
To generate the radiation, you've to excite the atoms to higher energy level through an external pump as in any laser or resonator cavity.
Moreover, the emission of electromagnetic radiation is not limited to infrared radiation. Atoms can emit EM radiation across the entire electromagnetic spectrum, depending on the energy of the transition and the energy difference between the two energy levels involved.
For example ASML uses CO2 laser on molten tin to extract extreme Ultra Voilet radiation that is ground-breaking and no other company has ever been able to do that.
In the end, i noticed that some people used chatgpt to answer your question, please demotivate them as it doesn't have some logical reasoning for now.
Read this book https://www.ifsc.usp.br/~strontium/Teaching/Material2011-2%20SFI5877%20Luzmateria/Weiner%20Light&matter.pdf
• A thorough discussion of the theory of absorption and emission of radiation from multilevel (real) atoms can be found in
Sobelman, I. I., Atomic Spectra and Radiative Transitions, Springer Verlag, Berlin (1977)
• A comprehensive discussion of absorption and emission in real atoms, gas-phase laser action, and atomic spectroscopy with laser sources can be found in
Corney, A. Atomic and Laser Spectroscopy, Clarendon Press, Oxford (1977)
• Early history of the quantum theory and the problem of black-body radiation may be found in
J. C. Slater, Quantum Theory of Atomic Structure vol. I, chapter 1, McGraw-Hill, New York, 1960
