Can Electromagnetic Waves Travel as Photons?

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Discussion Overview

The discussion revolves around the relationship between electromagnetic (EM) waves and photons, specifically whether all electromagnetic waves can be considered to travel as photons. Participants explore the definitions of light and electromagnetic radiation, the nature of photons, and the implications of these concepts in various contexts.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants argue that if light is transmitted as photons and all light is electromagnetic waves, then it follows that all electromagnetic waves travel as photons.
  • Others contend that while all light is electromagnetic radiation, not all electromagnetic waves are classified as light, suggesting a distinction based on the spectrum.
  • One participant emphasizes that photons correspond to all types of electromagnetic waves, including gamma-ray, X-ray, microwave, and radio-wave photons, differing only in energy.
  • Another viewpoint suggests that the term "light" is often used to refer specifically to the visible part of the electromagnetic spectrum, while other forms of EM radiation, like X-rays and gamma rays, are not typically classified as light.
  • A participant describes photons as a convenient conceptual tool for quantifying electromagnetic radiation, linking them to energy and momentum preservation.
  • There is mention of the equation \(E_{photon} = \frac{hc}{\lambda}\) to illustrate the relationship between energy, wavelength, and the nature of photons.
  • Some participants express uncertainty about the definitions and classifications of light and electromagnetic waves, indicating that the terminology can be ambiguous.

Areas of Agreement / Disagreement

Participants express differing views on whether all electromagnetic waves can be considered as traveling as photons. While some support this idea, others argue against it, leading to an unresolved discussion with multiple competing perspectives.

Contextual Notes

There are limitations in the discussion regarding the definitions of light and electromagnetic waves, as well as the implications of quantum mechanics on the particle-wave duality of photons. The conversation reflects varying interpretations and assumptions about these concepts.

Pengwuino
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If light is transmitted as photons... and all light is is electromagnetic waves... is it accurate to say all electromagnetic waves travel as photons?
 
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Eh... logically, no: if all light is electromagnetic waves, that doesn't mean all EM waves are light.

It's a bit hard to interpret your question though; sure, all EM waves propagate as waves, with a certain amplitude and a certain phase... so does light, because of its wave effects... I don't really see your point though.

I can tell you the inverse: no, I don't see how it can be possible that EM waves have a different sort of propagation than the kind of light waves... all waves are more or less similar.
 
Last edited:
Pengwuino said:
is it accurate to say all electromagnetic waves travel as photons?

Sure. There are gamma-ray photons, X-ray photons, microwave photons, radio-wave photons,... The only difference is the energy of the individual photons, as per

[tex]E_{photon} = hf = \frac {hc}{\lambda}[/tex]
 
Pengwuino said:
If light is transmitted as photons... and all light is is electromagnetic waves... is it accurate to say all electromagnetic waves travel as photons?

Light is just a part of the entire EM-spectrum and since photons are the particles that correspond to EM-waves, the answer to your question is YES.

Beware that when we speak about particles, don't think of objects with clear finite spatial boundaries. This is NOT the case because the position is uncertain in QM due to the HUP. When we talk about particles in the particle wave duality we mean : particle like behaviour : photons are 'little' finite pieces of energy.

regards
marlon
 
Ok so is "light" defined only as IR, UEV, visible, etc and not x-ray, gamma, short wave, etc?

I know all of those represents a portion of the RF spectrum, but I am asking if say, x-ray is accurate in being called "light" just like visible light is "light".
 
Pengwuino said:
If light is transmitted as photons... and all light is is electromagnetic waves... is it accurate to say all electromagnetic waves travel as photons?
Tsunami's right, logically speaking. All light is em, all em "packets" are photons, therefore all light "packets" are photons. Not quite as you stated it, but close enough. Honestly speaking, though some may differ decidedly, in general if
[tex]E_{photon} = \frac {hc}{\lambda}[/tex]
holds, call it light to your heart's content. Whether or not it's visible to the human eye is irrelevant.
 
I see the photon as an imaginary particle to fulfil momentum and energy preservation. Therefore the photon quantifies the EM radiation. i.e I see it as the power or ampplitude squared of the EM wave integrated over a certain time period. It is convenient solution.

Look at it this way, your GSM mobile telephone operating at 800MHz and transmitting say at 0,5W needs to emmit 9.43 x 10^23 photons every second when transmitting. No wonder your ear gets cooked by all those photons.
 
Pengwuino said:
Ok so is "light" defined only as IR, UEV, visible, etc and not x-ray, gamma, short wave, etc?

No, what we call light is just the visible part of the EM-spectrum. IR, UV, X-radiation are other parts of the EM-spectrum (other energies or wavelengths)...So EM-radiation is the general name, if you will.

marlon
 
someone correct me if I am in any way wrong, I'm not a physicist after all, but the important thing is that these bundles, packets, quanta, have an energy cracterized by
[tex]E_{photon} = \frac {hc}{\lambda}[/tex],
which shows that these discreet energies are dependent upon their wavelengths. The photons travel with a velocity c, held to be a constant. Then, by,
[tex]c = {f\lambda}[/tex]
there are many wavelengths which satisfy the relation. While light technically only refers to those wavelengths in the visible part of the spectrum, it is not uncommon to use it as a geneal term for all em radiation, anything which satisfies the above relation.
 
  • #10
inquire4more said:
Tsunami's right, logically speaking. All light is em, all em "packets" are photons, therefore all light "packets" are photons. Not quite as you stated it, but close enough.

Well after looking at it, what you answered was closer to what i was thinking and what i was thinken wasnt really what i wrote down accurately.
 

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