It is generally agreed upon that electromagnetic waves from an emitter do not have to connect to a receiver, but how can we be sure this is a fact? The problem is that we can never observe non-received EM-Waves, because if we observe them the instrument of observation becomes a receiver.
Electromagnetic waves have changing electric and magnetic fields and are both electric and magnetic. Electric current connects like from an anode to a cathode. Magnetic fields illustrated by flux lines connect from one magnetic pole to another, and no non-connecting flux lines are observed.
So electric currents connect and magnetic fields connect, so why doesn’t the electromagnetic wave also always connect to a receiver? A receiver which could be a plasma particle, a planet, a star and anything else which can absorb EM-radiation.
There is one big problem. If a photon has to be emitted in the direction of a future receiver, the photon must know where a future receiver will be. So this conflicts with our view on causality, or a cause creating an effect. And as the emitter doesn’t know where the receiver will be some time in the future, it can't emit an EM-wave against it.
But how can we know that the causality principle is always valid without exceptions? There seems to be reasons for questioning the universal validity of the causality principle:
Information does not have a mass and may then not be restricted by the speed of light, so the causality principle may not always hold for massless particles/waves.
When something travels with the speed of light, it will experience that distance become zero. If there is no distance, there is a full connection and a continuous electromagnetic wave between the emitter and receiver. Again, using the photon as a reference frame is not something relativistic physicists seem to like.
Maxwell's electromagnetic wave equation has a simple and an advanced solution. The advanced solution is usually discarded because the effect happens before the cause. But in Wheeler–Feynman absorber theory the advanced solution is used because it works. See this link for more information: http://en.wikipedia.org/wiki/Wheeler%E2%80%93Feynman_absorber_theory
The field of quantum mechanics is discussing many different causality problems. Like the observation of a particle might decide where the particle will be in time and space. Relevant to this discussion is the question of what triggers the atom to emit light:
Over the last hundred years, physicists have discovered systems that change from one state to another without any apparent physical “trigger.” These systems are described by quantum mechanics.
The simplest such system is the hydrogen atom. It’s just an electron bound to a proton. Two particles – that’s about as simple as you can get. According to QM, the electron can occupy one of a discrete set of energy levels. The electron can be excited to a higher energy level by absorbing a photon…
When the electron drops from a higher energy level to a lower level, it emits a photon: a quantum of light…
Quantum mechanics describes this process beautifully, but it only predicts the average time the electron will stay in the higher energy level. It doesn’t give any clue as to the specific time the electron will drop to the lower level. More precisely, the transition rate (the probability of a transition per unit time) is constant: it doesn’t matter how long it has been since the atom was excited, the transition rate stays the same…
When you first encounter this, you can’t quite wrap your brain around it. Surely there must be some internal mechanism, some kind of clock, that ticks along and finally “goes off,” causing the transition!
But no such mechanism has ever been found. QM has had an unexcelled record of accurate predictions, without any need for such a mechanism…” -George Mason University physicist, Robert Oerter
So is the excited atom a random generator or is it something external that triggers the release of a photon? It seems like it’s something external, and this external trigger might be the unphysical connection to a future receiver described by the advanced solution to Maxwell’s equation of electromagnetic radiation.
So it seems to me like we currently can’t be sure if a photon is always emitted against a receiver, or it is emitted randomly in any direction into space. But this question might be one of the most important questions ever asked, because if an electromagnetic wave is always connected to a receiver the implications are vast. It could shed light on the discussion of many topics. It might change our view on time and space. It might not only be the past pushing the present forward, but the future pulling on the present, making a syntropy which will create order out of chaos, and describe the marvelous universe we live in. Even the view of the present itself as a sharp line between the past and the future could be questioned. Time itself might not be totally linear, and the future may change the past. To avoid paradoxes with time travel we have to allow a number of parallel universes, as suggested by American physicist Hugh Everett who formulated the idea of their existence to explain the theory that every possible outcome of every choice we have actually does happen.
But before we can fully dive into all these fascinating questions, we have to solve this question:
Does an electromagnetic wave always have to connect to a receiver?
This hypothetical question might seem purely philosophical, but it is not. And it might even be confirmed by observations. We can’t directly observe non-received photons, but we might indirectly observe the existence or nonexistence of these photons. Any answer or suggestions are most welcome.