Radiative and Reactive EM Fields
wirebender and I have been having a discussion about fields.
radiative fields are the simpliest. the particle producing it is shedding energy by emitting a photon in a random direction therefore the field is spherical in shape and the individual photons exist at the same energy level (minus adjustment for expansion of space) until they are absorbed elsewhere.
reactive fields are much different. they are produced by magnetic or electric potentials that want to transfer force. they do not emit free photons of a specific energy in a necessarily spherical shaped field.
how many people have a clear idea of how magnetism or electrical force is transfered other than to do the calculations of classic theory? no one or very few. how does the field know exactly the right energy photon to send out in exactly the right direction? are there any stray photons that missed the mark? if more photons were sent out than were absorbed where did that extra energy come from? by all accounts there are no extra photons.
I cant tell you the answer. it is far more complicated than I would care to learn, perhaps more complicated than I could learn.
but the extremely simplified version is this. charged particles are surrounded by virtual particles including virtual photons that only exist for time periods defined by the Heisenberg Uncertainty Principle. a very, very short time. these are the photons that go out and find the other charged particles to transfer force with. but how does the virtual photon get to the other charged particle if it doesnt exist long enough to travel there?
an excellent question, worthy of being yet another facet of quantum weirdness. photons travel at the speed of light. the equations for relativity include a divisor that is c2-speed2. dividing by zero is undefined. you cannot define distance or time relative to the photon. in essence the photon exists along its whole path all the time.
that is why the virtual photon can go out and react with any available charged particle no matter how far away. once it finds the particle it becomes a real photon and exchanges the force. any unused virtual photons just cease to exist past their expiry date.
wirebender has mixed up the two types of field. he thinks simple radiative field have the same properties as reactive fields. or something. in any case he thinks radiative photons like those emitted from an excited CO2 molecule can wink out of existence because other radiation is coming from the earth in the opposite direction. other than a simple waveform disturbance at the meeting point both photons carry on as if nothing happened.
anyways, that is my ultra basic and simplified version of photons as carriers of energy. I would be pleased to describe my take on how electric and magnetic forces can be either attractive or repulsive if any one cares enough to ask.
wirebender and I have been having a discussion about fields.
radiative fields are the simpliest. the particle producing it is shedding energy by emitting a photon in a random direction therefore the field is spherical in shape and the individual photons exist at the same energy level (minus adjustment for expansion of space) until they are absorbed elsewhere.
reactive fields are much different. they are produced by magnetic or electric potentials that want to transfer force. they do not emit free photons of a specific energy in a necessarily spherical shaped field.
how many people have a clear idea of how magnetism or electrical force is transfered other than to do the calculations of classic theory? no one or very few. how does the field know exactly the right energy photon to send out in exactly the right direction? are there any stray photons that missed the mark? if more photons were sent out than were absorbed where did that extra energy come from? by all accounts there are no extra photons.
I cant tell you the answer. it is far more complicated than I would care to learn, perhaps more complicated than I could learn.
but the extremely simplified version is this. charged particles are surrounded by virtual particles including virtual photons that only exist for time periods defined by the Heisenberg Uncertainty Principle. a very, very short time. these are the photons that go out and find the other charged particles to transfer force with. but how does the virtual photon get to the other charged particle if it doesnt exist long enough to travel there?
an excellent question, worthy of being yet another facet of quantum weirdness. photons travel at the speed of light. the equations for relativity include a divisor that is c2-speed2. dividing by zero is undefined. you cannot define distance or time relative to the photon. in essence the photon exists along its whole path all the time.
that is why the virtual photon can go out and react with any available charged particle no matter how far away. once it finds the particle it becomes a real photon and exchanges the force. any unused virtual photons just cease to exist past their expiry date.
wirebender has mixed up the two types of field. he thinks simple radiative field have the same properties as reactive fields. or something. in any case he thinks radiative photons like those emitted from an excited CO2 molecule can wink out of existence because other radiation is coming from the earth in the opposite direction. other than a simple waveform disturbance at the meeting point both photons carry on as if nothing happened.
anyways, that is my ultra basic and simplified version of photons as carriers of energy. I would be pleased to describe my take on how electric and magnetic forces can be either attractive or repulsive if any one cares enough to ask.
