# Can Electromagnetic Waves Travel as Photons?

• Pengwuino
In summary: I was thinking in the sense of, if all light is EM, and light is only EM, then is it accurate to say that all EM is light? But you pretty much answered thatIs it accurate to say all electromagnetic waves travel as photons?In summary, all electromagnetic waves, including light, can be described as photons. This means that all electromagnetic waves, regardless of their energy or frequency, have particle-like behavior and can be quantified as discrete packets of energy. However, the term "light" typically refers to the visible part of the electromagnetic spectrum, while other parts such as x-rays and gamma rays are still considered electromagnetic waves but may not be referred to as "light."
Pengwuino
Gold Member
If light is transmitted as photons... and all light is is electromagnetic waves... is it accurate to say all electromagnetic waves travel as photons?

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

$$E_{photon} = hf = \frac {hc}{\lambda}$$

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
$$E_{photon} = \frac {hc}{\lambda}$$
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

Somone 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
$$E_{photon} = \frac {hc}{\lambda}$$,
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,
$$c = {f\lambda}$$
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.

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.

## 1. What are electromagnetic waves?

Electromagnetic waves are a type of energy that is transmitted through space in the form of oscillating electric and magnetic fields. They do not require a medium to travel and can move at the speed of light.

## 2. What are photons?

Photons are the smallest unit of light and are considered to be particles of electromagnetic radiation. They have no mass and travel at the speed of light in a vacuum.

## 3. How are electromagnetic waves and photons related?

Electromagnetic waves are composed of photons. As the wave travels through space, the photons oscillate between electric and magnetic fields. The energy of the wave is carried by the photons.

## 4. Can electromagnetic waves travel without photons?

No, electromagnetic waves cannot exist without photons. The photons are the carriers of energy and without them, there would be no oscillating electric and magnetic fields to create the wave.

## 5. Can electromagnetic waves travel through all materials?

Electromagnetic waves can travel through most materials, but the speed and intensity of the wave may be affected. Some materials, such as metals, can reflect or absorb electromagnetic waves, while others, such as glass, can allow them to pass through with little resistance.

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