How short can electromagnetic radiation become? Shorter than gamma rays?

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Discussion Overview

The discussion centers around the limits of electromagnetic radiation wavelengths, specifically whether there can be radiation shorter than gamma rays. It explores theoretical boundaries, the nature of the electromagnetic spectrum, and implications for extreme conditions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants suggest there is no known limit on how short the wavelength of electromagnetic radiation can become, with distinctions made between X-rays and gamma rays based on their origins.
  • One participant notes that the limit for long wavelengths is the size of the universe, while proposing that the short wavelength limit may be around the Planck length.
  • Another participant emphasizes the continuity of the electromagnetic spectrum, arguing that practical boundaries arise from technology rather than strict definitions.
  • A later reply questions whether human measurement is necessary for defining these boundaries, suggesting that extreme conditions might lead to phenomena beyond current measurement capabilities, potentially relating to theories like String Theory.

Areas of Agreement / Disagreement

Participants express differing views on the existence of limits to electromagnetic radiation wavelengths, with no consensus reached on whether radiation shorter than gamma rays can exist.

Contextual Notes

Participants reference various theoretical concepts, including the Planck length and String Theory, which may not be universally accepted or understood. The discussion also highlights the dependence on technological capabilities for measuring and generating electromagnetic signals.

Doug1943
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is there some physical limit on the wavelength of electromagnetic radiation? Can there be radiation shorter than gamma rays?
 
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No, because gamma has no lower bound on the wavelength. If it's shorter than X-rays, it's called gamma rays. Just as everything at the other end of the spectrum is called "radio waves" and there's no limit on how long those wavelengths can be. They're still called "radio".
 
There is no known limit on how short the wavelength of an EM wave can become. Everything past a certain frequency is either x-rays (if they originate from outside an atomic nucleus) or gamma rays (if they originate from the decay of an atomic nucleus).
 
Moderator's note: Moved thread to Classical Physics forum.
 
The limit for long wavelengths is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length (1.616255(18)×10−35 m)
From https://en.wikipedia.org/wiki/Electromagnetic_spectrum
which cites Bakshi, U. A.; Godse, A. P. (2009). Basic Electronics Engineering. Technical Publications. pp. 8–10
 
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The continuity of the electromagnetic spectrum may be one of the most beautiful discoveries in physics. From the same source as above:
Note that there are no precisely defined boundaries between the bands of the electromagnetic spectrum; rather they fade into each other like the bands in a rainbow (which is the sub-spectrum of visible light).
Practical boundaries arise from technology. We can ask given current technology, what is the highest frequency -- shortest wavelength signal -- human devices can generate? Or that we can detect and at what energy?
 
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Klystron said:
The continuity of the electromagnetic spectrum may be one of the most beautiful discoveries in physics. From the same source as above:

Practical boundaries arise from technology. We can ask given current technology, what is the highest frequency -- shortest wavelength signal -- human devices can generate? Or that we can detect and at what energy?
This assumes that human measurement is a requirement. I think the OP probably had in mind processes taking place in conditions that are too extreme to allow measurement. This takes us into the sort of situations where String Theory could be tested and beyond and we don't yet have the ability to go there.
 
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