Can Photons Generate Electromagnetic Waves Without Being Charged?

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Discussion Overview

The discussion revolves around the nature of photons and their relationship with electromagnetic (EM) waves, exploring whether photons can generate EM waves without being charged, and the implications of speed, mass, and momentum in this context. Participants examine theoretical concepts, definitions, and the behavior of light in different media.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that anything moving at high speed might generate electromagnetic waves, questioning if photons, despite being uncharged, could create electric fields due to their speed.
  • Others argue that electromagnetic waves are produced by accelerated charges, not merely by moving charges, and emphasize the distinction between photons and classical EM waves.
  • There is a suggestion that photons might be considered as particles of vacuum, but this is challenged by other participants who assert that photons are not simply small particles moving quickly.
  • One participant questions the nature of charge and the interaction of photons with charges, pondering if field lines could be analogous to moving photons.
  • Another participant expresses confusion about light's behavior, noting that it does not have mass and questioning its classification as either a wave or a particle.
  • Some participants clarify that electromagnetic waves can exist without mass and that photons exist in the context of EM waves, regardless of their speed in different media.
  • There is a discussion about the momentum of EM waves and whether this implies mass, with some asserting that momentum does not equate to mass for photons.
  • Participants debate the existence of photons in classical physics versus quantum mechanics, with some suggesting that classical EM waves do not involve photons.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the nature of photons and EM waves, with no consensus reached on several key points, including the relationship between speed, mass, and the generation of electromagnetic waves.

Contextual Notes

Participants highlight limitations in understanding the definitions of mass and momentum in relation to photons and EM waves, as well as the implications of different speeds in various media. There is an acknowledgment of the complexity of the concepts being discussed.

Markovnikov ya
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Can I assume that anything with high enough speed will generate electromagnetic wave? Photons are not charged. But maybe because they move fast enough, they generate vortex electric field, since this field is changing, then you have a corresponding magnetic field with it, so you have an electromagnetic wave. So, if the speed of the particle is fast enough, you can generate electric field without the particle being charged?

So, can I say that a photon is simply a very small particle moving very fast, and generating electromagnetic wave?

Or ,maybe photons are particles of vacuum?
 
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Markovnikov ya said:
Can I assume that anything with high enough speed will generate electromagnetic wave?

No, an EM wave is not generated by moving charges, but by accelerated charges.

Photons are not charged. But maybe because they move fast enough, they generate vortex electric field, since this field is changing, then you have a corresponding magnetic field with it, so you have an electromagnetic wave. So, if the speed of the particle is fast enough, you can generate electric field without the particle being charged?

Don't mix photons with classical EM waves until you know everything you can about the latter. Otherwise you will only confuse yourself. I know this from experience!

So, can I say that a photon is simply a very small particle moving very fast, and generating electromagnetic wave?

You cannot. Photons are not little particles moving quickly through space. They do not travel like bullets from a gun. They are the quantized interaction of the EM wave with matter. This just means that if you measure the energy of an EM wave you will find that it is transferred in "chunks", and not in a continuous manner.

Or ,maybe photons are particles of vacuum?

They are not.
 
What is the charge then? the photon is the one who provides interaction between charges, but what is it in the charge that makes photon "move"?

Can I assume that field lines are moving photons?

Are field lines like the wind and photons like the moving sand? Only to move each grain of sand you need the wind to be able to force each grain to move with a speed of light?
 
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Markovnikov ya said:
What is the charge then? the photon is the one who provides interaction between charges, but what is it in the charge that makes photon "move"?

There isn't one. Photons move at c though a vacuum always. Charges do not make them move like they would do for another charged particle.

Can I assume that field lines are moving photons?

Absolutely not. Field lines are representations of the electric or magnetic field. They do not actually exist. They simply aid us in visualizing what a particle or other object will do when placed in a field.

The best thing you can do right now is to absolutely forget everything you know about photons. I guarantee you it is not correct and will only confuse you. Then, study up on what a classical EM wave is and why it behaves the way it does.
 
ok, will do so, thank you:)
 
I am trying to understand light, it is so weird. Light is not an electromagnetic wave, since it has different speed in different mediums. Light does not have mass (the mass that can be derived from the energy is not a real mass), so its not a particle either. What is it?

Back to my original question about EM wave being a matter. Well, it has energy, it has speed of distribution, it exerts pressure on reflecting or absorbing particles, so it must have a mechanical momentum, if it has momentum, then it must have mass. So it has all the components necessary to be considered matter. But its speed in any medium is the speed of light. But you cannot say the same thing about light, its speed changes with change in refractive index of the medium.

Ok, you are saying that electromagnetic wave is a lot of photons. But the waves' speed changes as the refractive index of the medium changes. Yet photons can only exist while moving with the speed of light. Maybe that is where some of the photons are absorbed by the medium (or reflected). Yet the light still exists (because some photons got through the medium without change in speed?), only with smaller intensity? But then I don't understand. EM wave moves in any medium with a speed of light, no matter what the refractive index is. Then why doesn't the EM wave of light disappear when some photons are absorbed?

I guess the question would be: WHy is any light absorbed at all if EM wave is supposed to travel at a speed of light through all mediums? It means that light is not EM at all! my head hurts.
Or does it mean that light is light and EM wave is EM wave. And classical EM wave does not have any photons?
 
Markovnikov ya said:
I am trying to understand light, it is so weird. Light is not an electromagnetic wave, since it has different speed in different mediums. Light does not have mass (the mass that can be derived from the energy is not a real mass), so its not a particle either. What is it?

Light is most certainly an EM wave. It has a wavelength between 350 and 700 nanometers or so. This is much much smaller than something like a radio wave for an FM station, which has a wavelength measured in whole meters.

Back to my original question about EM wave being a matter. Well, it has energy, it has speed of distribution, it exerts pressure on reflecting or absorbing particles, so it must have a mechanical momentum, if it has momentum, then it must have mass. So it has all the components necessary to be considered matter. But its speed in any medium is the speed of light. But you cannot say the same thing about light, its speed changes with change in refractive index of the medium.

Not true. All EM waves have a reduced velocity when traveling through a medium. And they do not have mass.

Ok, you are saying that electromagnetic wave is a lot of photons. But the waves' speed changes as the refractive index of the medium changes. Yet photons can only exist while moving with the speed of light.

Photons exist whenever you have an EM wave, no matter how fast its moving or what its moving through.

Or does it mean that light is light and EM wave is EM wave. And classical EM wave does not have any photons?

In classical physics photons do not exist. An EM wave is solely the changing electric and magnetic fields propagating through space. Quantum Mechanics, and later Quantum Electrodynamics explains EM waves as photons and is much more accurate than classical physics.

It would greatly help your understanding if you forget about photons altogether for now and just get the basics of a classical EM wave down.
 
Hold on, so classical EM wave has different velocities in different mediums?
 
Markovnikov ya said:
Hold on, so classical EM wave has different velocities in different mediums?

Absolutely.
 
  • #10
You are saying that EM waves do not have mass.
But let's say we have a medium and a wave is absorbed. Doesn't it mean that the wave must put pressure on the particle in order to be absorbed? i mean, if you have electric and magnetic fields in a EM wave, then electric field would cause some small current and then magnetic field would influence these small currents, directing them into the medium, which would cause pressure. And if you have something that can cause pressure, doesn't it mean that the electric field in the EM wave has momentum. And then if you have momentum, wouldn't that mean that the object has mass?

Also, if EM wave always has photons, then does it mean that EM wave can only exist when its' speed is equal or greater than the speed of light?
 
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  • #11
Markovnikov ya said:
And then if you have momentum, wouldn't that mean that the object has mass?

No. Photons (or the EM wave, whichever way you look at it) carry momentum but have no mass.

Also, if EM wave always has photons, then does it mean that EM wave can only exist when its' speed is equal or greater than the speed of light?

A photon is the quantized interaction of an EM wave. It is not some little particle that just happens to travel along with the wave. And how could an EM wave's speed be greater than the speed of light when the EM wave itself IS light?
 
  • #12
ok, thank you. I'll keep on studying:)
 

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