Electromagnetic fields and empty space

In summary, according to current science, the early universe was dominated by ionizing radiation, which created photons. Those photons are not matter- they are electromagnetic radiation. Matter comes from the combination of subatomic particles that result from ionizing radiation.
  • #1
nouveau_riche
253
0
is it possible for electromagnetic field to exist without matter?
 
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  • #2
Yes, it is.
That's one of the particulars of 20th century physics.
People have thought for a long time that electromagnetic fields should propagate through some medium, in the same way that water waves or sound do. To explain EM waves propagating through vacuum they invented the concept of something called ether, permeating throughout space.
Ironically the experiment of Michaelson and Morley, which intended to prove the existence of that substance, was one of the major factors in discarding it.
 
  • #3
Yep! Just look at a photon!
 
  • #4
Doesn't the EM field require the existence of charged particles to form?
 
  • #5
light isn't a charged particle but it is an oscillating ripple in the EM field. But I couldn't tell you why.
 
  • #6
I think what OP wants to know is that electromagnetic wave can propagate without a medium, but can you create them without charged matter somewhere. Yes, You need some oscillating charge somewhere to create them, except maybe for fluctuation of the vacuum.

On the other hand, one predicted death of the universe is that everything, including proton, decays to photons so far away from each other that they never interact. So I suppose that'd be the case of photon without matter.
 
  • #7
timthereaper said:
Doesn't the EM field require the existence of charged particles to form?

mathfeel said:
I think what OP wants to know is that electromagnetic wave can propagate without a medium, but can you create them without charged matter somewhere. Yes, You need some oscillating charge somewhere to create them, except maybe for fluctuation of the vacuum.

On the other hand, one predicted death of the universe is that everything, including proton, decays to photons so far away from each other that they never interact. So I suppose that'd be the case of photon without matter.

Remember that according to current science, the universe itself was once all photons. So where did those photons come from if they needed charged particles to create them?
 
  • #8
In principle it would be possible to have a universe with no charges, but with radiation. The early universe was radiation-dominated.

Edit: looks like Drakkith beat me to it!
 
  • #9
DaleSpam said:
In principle it would be possible to have a universe with no charges, but with radiation. The early universe was radiation-dominated.

The early universe was dominated by ionizing radiation, wasn't it? So charge must have preceded matter.

Respectfully,
Steve
 
  • #10
Dotini said:
The early universe was dominated by ionizing radiation, wasn't it? So charge must have preceded matter.
The phrase "ionizing radiation" just refers to radiation of sufficiently high energy that it could ionize an atom. It by no means implies anything about its origin.
 
  • #11
Drakkith said:
Remember that according to current science, the universe itself was once all photons. So where did those photons come from if they needed charged particles to create them?

i asked for electromagnetic fields to exist without matter,that itself excludes photon
 
  • #12
nouveau_riche said:
i asked for electromagnetic fields to exist without matter,that itself excludes photon

How so? Photons ARE electromagnetic fields. Or rather oscillations in them or whatever. If photons existed before matter then that is an example of EM fields existing without matter.
 
  • #13
Drakkith said:
How so? Photons ARE electromagnetic fields. Or rather oscillations in them or whatever. If photons existed before matter then that is an example of EM fields existing without matter.

because photon itself is matter
 
  • #14
nouveau_riche said:
because photon itself is matter

No, photons are not matter. They are electromagnetic radiation.
 
  • #15
DaleSpam said:
In principle it would be possible to have a universe with no charges, but with radiation. The early universe was radiation-dominated.

Hold on- at sufficiently high temperatures there is the matter-antimatter-radiation equilibrium, and when the temperature drops, matter and antimatter combine to form radiation and whatever is left. It's at this point that you look and see that there are many more photons than protons/electrons, and conclude "the early universe was radiation dominant"...

Radiation dominant doesn't mean there wasn't matter, simply that the matter/antimatter difference was so slight that when they combined, most of the matter was converted to radiation, leaving a small amount of matter, and a relatively large amount of radiation (dominant == considerably higher energy density).

I don't believe radiation dominant can be used for an argument that the electromagnetic field can exist without there ever previously being any charge present. That radiation came from charge/anticharge interactions in the first place.
 
  • #16
Drakkith said:
No, photons are not matter. They are electromagnetic radiation.

so what makes matter as matter?how can photon exist without existence of matter?
 
  • #17
nouveau_riche said:
so what makes matter as matter?how can photon exist without existence of matter?

Maybe photons would exist, but would you know it unless it had a material surface to light up?

I see electrons, protons and other subatomic particles coming together from the regime of ionizing radiation to form atoms and molecules.

Respectfully submitted,
Steve
 
  • #18
nouveau_riche said:
so what makes matter as matter?how can photon exist without existence of matter?

"Matter" in physics is any object or particle that has mass. Photons have no mass and are not considered matter. If you want to use the word "matter" to describe anything that exists or can exist, massive and massless, then the word becomes useless.
 
  • #19
MikeyW said:
Hold on- at sufficiently high temperatures there is the matter-antimatter-radiation equilibrium, and when the temperature drops, matter and antimatter combine to form radiation and whatever is left. It's at this point that you look and see that there are many more photons than protons/electrons, and conclude "the early universe was radiation dominant"...

Radiation dominant doesn't mean there wasn't matter, simply that the matter/antimatter difference was so slight that when they combined, most of the matter was converted to radiation, leaving a small amount of matter, and a relatively large amount of radiation (dominant == considerably higher energy density).

I don't believe radiation dominant can be used for an argument that the electromagnetic field can exist without there ever previously being any charge present. That radiation came from charge/anticharge interactions in the first place.

I've always wondered what exactly existed at that time. From my reading on the subject I had assumed it was only/primarily radiation. However I can see if there were constantly matter and antimatter being created an annihilated.
 
  • #20
Dotini said:
Maybe photons would exist, but would you know it unless it had a material surface to light up?

I see electrons, protons and other subatomic particles coming together from the regime of ionizing radiation to form atoms and molecules.

Respectfully submitted,
Steve

chrisbaird said:
"Matter" in physics is any object or particle that has mass. Photons have no mass and are not considered matter. If you want to use the word "matter" to describe anything that exists or can exist, massive and massless, then the word becomes useless.

how does then the essence of electric and magnetic field (in photon) could be there without any charge actually being there?
what is there to ionize ,if only photons were the only one existing at that time?
or in your case how can ionization give charge?
 
  • #21
MikeyW said:
Radiation dominant doesn't mean there wasn't matter
I know that. To my understanding the OP's question is obviously not a question about this universe since there ARE charges in this universe. The question is if a hypothetical universe using the same laws of physics as ours could be theoretically possible.

The answer to that seems to be "yes", IMO. The laws of physics don't forbid it (vacuum solutions to Maxwell's equations) and this universe was reasonably close to such a condition at one time (radiation dominated).
 
  • #22
nouveau_riche said:
how does then the essence of electric and magnetic field (in photon) could be there without any charge actually being there?
what is there to ionize ,if only photons were the only one existing at that time?
or in your case how can ionization give charge?

I'm certainly no expert. But, in our universe, I think charge (dipolarity) must have preceded photons and matter (elementary atoms), and that electric and magnetic fields also must have existed prior to photons and matter. First come the rules, then the pieces of the game. I'm trying to get the minimum number of rules and pieces on the board to self-assemble into what we see today.

I have a question for the experts about spin - is it a property of polarity, or is it considered energy, or both?

Respectfully,
Steve
 
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  • #23
Dotini said:
I'm certainly no expert. But, in our universe, I think charge (dipolarity) must have preceded photons and matter (elementary atoms), and that electric and magnetic fields also must have existed prior to photons and matter. First come the rules, then the pieces of the game. I'm trying to get the minimum number of rules and pieces on the board to self-assemble into what we see today.

I have a question for the experts about spin - is it a property of polarity, or is it considered energy, or both?

Respectfully,
Steve

if charge came earlier,so will be the mass unless the temperature is so high at that time to avoid sufficient interactions
and what do you mean by the property of polarity?,please elaborate
 
  • #24
nouveau_riche said:
what do you mean by the property of polarity?,please elaborate

General examples of polarity:
- positive/negative
- left/right
- male/female
- light/dark
- yin/yang

Respectfully,
Steve
 
  • #25
Dotini said:
General examples of polarity:
- positive/negative
- left/right
- male/female
- light/dark
- yin/yang

Respectfully,
Steve

how are you relating polarity with the root of charge?,the way you define it tells the types
 

1. What is an electromagnetic field?

An electromagnetic field is a physical field that is created by electrically charged particles and affects the behavior of other charged particles. It is made up of both electric and magnetic components and is responsible for many phenomena, such as light, electricity, and magnetism.

2. How is an electromagnetic field created?

An electromagnetic field is created when electrically charged particles, such as electrons, are in motion. When these particles accelerate or move, they create a disturbance in the surrounding space, causing an electromagnetic field to form.

3. What is the role of empty space in electromagnetic fields?

Empty space, also known as a vacuum, plays a crucial role in electromagnetic fields. It is the medium through which the fields propagate and interact with charged particles. The properties of empty space, such as its electric permittivity and magnetic permeability, affect the strength and behavior of the electromagnetic field.

4. Can electromagnetic fields exist in empty space?

Yes, electromagnetic fields can exist in empty space. In fact, electromagnetic waves, which are a form of electromagnetic field, can travel through empty space at the speed of light. This is because empty space has a special property that allows electromagnetic waves to propagate without the need for a medium.

5. What are some applications of electromagnetic fields in empty space?

Electromagnetic fields in empty space have a wide range of applications, including communication technologies, such as radio, television, and wireless internet. They are also used in medical imaging, such as MRI machines, and in various industrial processes, such as welding and metal processing. Additionally, electromagnetic fields play a crucial role in understanding the behavior of celestial bodies, such as stars and planets.

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