What produces the photon?

[Theoretical]

It seems that radio wavelength experiments could shed some light on answering this question that I would like to understand.

 

Consider the following experiment. A circular coil antenna, preferably made of high resistivity material so as to immediately quench the electrical current. A power supply produces DC current through the wire, thus forming a magnetic field that extends outside the coil. The longer the current is held, the farther out the field stabilizes. Then, suddenly the current is removed from the coil. This produces a stream of photons that travel inward toward the center of the coil antenna. The photons point of origin are not from the coil. They are coming from outside the coil. We know the magnetic field is collapsing. For example a part of the field that is say 20 meters away will obviously take at least 20m/c seconds for the photons to arrive. Since the coil is high resistivity, the incoming photons have very little effect on the antenna, and therefore continue traveling.

 

Can someone please explain how the distant magnetic field created photons?

 

Greatly appreciated!

[swansont]

This produces a stream of photons that travel inward toward the center of the coil antenna.

 

Please establish that this is true.

In general, a changing magnetic field produces an electric field, and a changing electric field produces a magnetic field. Under the proper conditions, this will produce an EM wave.

[Theoretical]

 

Please establish that this is true.

 

In general, a changing magnetic field produces an electric field, and a changing electric field produces a magnetic field. Under the proper conditions, this will produce an EM wave.

Okay thanks for the reply. I'm not sure how you would like me to establish this. I think it's well established that DC current flowing through a coil produces a magnetic field outside of the coil. The measured distance just depends how sensitive your detector is. Similarly isn't it well established that if the DC current is abruptly removed from a coil, that an electromagnetic pulse will be generated even though there is no appreciable current flowing through the coil mediately after the current is turned off? I've seen oscilloscope shots at varying points that show the pulse travels inwardly to the coil then outwardly. Edited December 29, 2014 by Theoretical

[swansont]

Okay thanks for the reply. I'm not sure how you would like me to establish this. I think it's well established that DC current flowing through a coil produces a magnetic field outside of the coil. The measured distance just depends how sensitive your detector is. Similarly isn't it well established that if the DC current is abruptly removed from a coil, that an electromagnetic pulse will be generated even though there is no appreciable current flowing through the coil mediately after the current is turned off? I've seen oscilloscope shots at varying points that show the pulse travels inwardly to the coil then outwardly.

 

An oscilloscope measures voltage.

 

Just because you have an E or B field, or a combination, does not mean you have photons.

[Theoretical]

 

An oscilloscope measures voltage.

 

Just because you have an E or B field, or a combination, does not mean you have photons.

True. Please explain where the energy went that was put in the magnetic field. As stated, the coil material resistivity is high. Only a fraction of the energy went back into the coil. Edited December 29, 2014 by Theoretical

[swansont]

True. Please explain where the energy went that was put in the magnetic field. As stated, the coil material resistivity is high. Only a fraction of the energy went back into the coil.

 

But the current does not immediately go to zero, and you still have a current. A changing B field, as I said, induces an electric field. This drives current (which produces a field to oppose the change, which is Lenz's law) That accounts, as you say, for some of the energy loss.

 

You will get some photons, but I don't see why one would think they would be directed inward.

[Theoretical]

 

But the current does not immediately go to zero, and you still have a current. A changing B field, as I said, induces an electric field. This drives current (which produces a field to oppose the change, which is Lenz's law) That accounts, as you say, for some of the energy loss.

 

You will get some photons, but I don't see why one would think they would be directed inward.

The current in such an experiment is hundreds of times less than what's needed to even account for joule heating. Remember, the purpose of using high resistivity coil wire is to aid the transistor in preventing current.

 

Furthermore, the pulse can be detected miles away.

It seems that it's your understanding that most of the energy goes back into the coil. If that's the case, then ask yourself what happens when the wire resistivity is increased. Remember the collapsing field can't collapse faster than c. So the voltage caused by the collapsing field can only go so high, but yet we can increase the wire resistivity further yet, thus reducing the absorbed energy. Where does the energy go if it's not going out as photons? Obviously the magnetic field isn't going to stay there without any current in the coil once the coil supply is turned off.

 

What happens is the field collapses, and electromagnetic waves travel inwardly and eventually through the coil and then outward until they find something to absorb the energy. My original question still remains.

Sorry, I just made another post using the Fast post feature, but it seems the forum appended it to my last post.

[swansont]

The current in such an experiment is hundreds of times less than what's needed to even account for joule heating. Remember, the purpose of using high resistivity coil wire is to aid the transistor in preventing current.

 

Furthermore, the pulse can be detected miles away.

 

Then you don't have much of a field. But, so what? That doesn't really change anything.

 

You have built your scenario on a couple of premises that I don't know to be true: the photons travel inward, and originate outside the coil. If those are in fact not true, the question is nonsensical.

 

Besides, what's the frequency of the radiation you get? 30 MHz? Then the wavelength of the photons will be 10m. You can't really tell where the photon originated.

[Theoretical]

 

Then you don't have much of a field. But, so what? That doesn't really change anything.

 

You have built your scenario on a couple of premises that I don't know to be true: the photons travel inward, and originate outside the coil. If those are in fact not true, the question is nonsensical.

 

Besides, what's the frequency of the radiation you get? 30 MHz? Then the wavelength of the photons will be 10m. You can't really tell where the photon originated.

It's not a fixed frequency. The result is similar to when an object is dropped in a pond of water.

 

Did you see all of my text in my last post? I tried to add another post, but it just appended it to the last post making it seem like one post.

 

Like I say, for simplicity assume that the coil current can be quenched on demand. We know the field can only collapse so fast, not exceed c, and so the voltage pulse is limited. Do you believe the pulse will sit there collapsing, expanding, collapsing, expanding, indefinitely? And what about the field that's 10 meters out, or 100m, or 1000m? How could this occur without producing a far field. Far field is photons. The other option is that we see something similar to what occurs when we drop a pebble in a pond, or more specifically if we slowly press the water down and then instantly release it thus allowing the water to collapse inward.

[derek w]

the magnetic field collapses when the current stops because the electrons go back to random motion.

[Theoretical]

the magnetic field collapses when the current stops because the electrons go back to random motion.

That's not true. Look up radiation resistance, which is caused by a lagging field. If light traveled instantaneously then there would be no radiation resistance. The field at say 10 meters out does not instantly know that the current has stopped because the information is limited to the speed of light.