Are EM radiation frequencies quantified?

[cgw]

Maybe the wrong word but can you get electromagnetic radiation in any frequency or is there a "quantum" frequency for which all other frequencies are some integer multiple?
Related question - is there an absolute low and high frequency?

 

[ZapperZ]

Maybe the wrong word but can you get electromagnetic radiation in any frequency or is there a "quantum" frequency for which all other frequencies are some integer multiple?
Related question - is there an absolute low and high frequency?

The quantization of EM frequency is only a result of the boundary conditions. Under a free propagation, you can, in principle get all the frequencies that you want. There's no quantized values. This is essentially what get a synchrotron centers using insertion devices such as wigglers and undulators. You can vary the spacing of the magnetic undulators as large or as small as you want that is technically possible, and you get a whole continuous spectrum of freq.

Zz.

 

[vanesch]

I would even like to add to what ZapperZ said, and point out that this "frequency quantization" is already entirely present in classical electromagnetism.

 

[Sojourner01]

Related question - is there an absolute low and high frequency?

Short answer - nope. However, absurdly high frequencies have vast energy and are likely to blast whatever they hit into a shower of mesons and other weird stuff. Practically speaking, the frequency of a photon is only limited by the particulars of the process that creates it. Offhand, the most energetic collision I can think of is a cosmic ray proton-antiproton event, releasing two very, very energetic gamma rays.

 

[Claude Bile]

I'll state the obvious and point out that the absolute low frequency for EM radiation is an electric field that is constant w.r.t. time, which you would find anywhere you have a DC potential difference.

Claude.