geistkiesel
Valued Senior Member
Quantum Quack once posed a query of whether or not there is a proof that light actually moves. I dismissed the question with a dogmatic shrug and wrote something embarrassing and trite, from my own perspective.
What are the experimental results of detection of light motion?
It is all speculative and convenient not to have any basic unresolved issue here in the third millennium such as resolving whether light moves or othewrwise.
We start with the question of light being either, 1. Particle, 2. Mass, or 3. Both.
1. Light when measured by a photomultiplier tube has told us that if light is mass the mass is very, very tiny. Likewise, light behaves unlike the mass of buck-shot as it seems to be wave then particle. Momentum tests are unhelpful in determining mass or wave characteristics to light.
2. If a wave the measurement in 1. above sheds little light on the basic characteristics of particle photon phenomena.
3. Diffraction experiments gave birth to the ‘wave and particle’ notion. It is concluded that the experimental apparatus affects the wave particle aspect of light, but again nothing gives a clue re motion.
If light were moving after flipping the switch at A, then a particle would mean the same stuff that left A was the same stuff that rang the photomultiplier tube’s bell. The problem with necessary mass formation in every instance of an emitted light pulse that is measured requires a convincing arm waving talent beyond the mortals and beyond understandable scientific principles.
I am leaving out much that is left to the reader to sort through.
If light moves as a wave then the stuff that left A was other than the stuff arriving at B which forces the discussion to describing a medium being perturbed that leaves a trace wherever the light happened to “be”. The forced tongue twister description of the true nature of the so called wave leaves much to mathematical speculation; to the extent that light can be manipulated even in this gross state of ignorance, hence the wave nature is left for after hours contemplation over a few ales at a friendly pub.
Dual descriptions offer even more complexities that defy rational analysis. The bottom line is that the current [or not too distant past] giants of science, whoever they may be, offer us solace by not making an issue of the impossible problem.
What happens when we look very deeply quantum mechanically? The locations of particles become smeared as we near the location of the particle 'under scrutiny'. We cannot discern wave, mass or structure, but we can surmise that no bunch of matter is “always” in some observable state in the sense that buck-shut doesn’t rapidly decay. Matter is there, and then it goes away. The stuff of matter, or some stuff, is generally understood as problematical, or a statistical reality. We only see stuff move that has accumulated a large observable bunch of problematical stuff seen as periodic excitations of matter in space.
What is light doing?
All we can say is that the light switch applies a potential to some part of a device that receives an energy pulse and likewise, must give a pulse that is absorbed by a near neighbor in space. Looking at space as a field of possible excitations, motion then becomes nothing more than the excitation of a point in space and where that excited point cascades through space analogous to the motion of falling dominoes.
There is, for sure, momentum exchanges that are straight forward in understanding. When a high energy photon is detected by human skin the momentum felt is simply the reaction of the target substance to the arrival of the near neighbor pulse.
So what is light doing?
When considering the apparent limitless energy of electron and nucleus holding onto each other, not as hooks, but as complex electro-nuclear systems, the illusion of identifiable quantities of stuff becomes undisguised. The energy and all possible forms of substances including the electric/nuclear fields of electron and nucleus in the final analysis are merely statistical and problematic.
Looking at the description simple mindedly, the motion of light as we once believed, has been transformed into the execution of a complex software package where motion, trajectory, momentum are just the manifestation of subroutines inherent in an object oriented program where the source code is identifiable, within limits, to the familiar laws of physic, as we know, or think we know the laws to be.:shrug: