The light invariance principle is valid for the light in vacum. From it follows that the light is unaffected from the source movement, it lives in a space that can be properly called 'absolute space'. During its path light is unaware of anything that happens around it. What about of the light in a medium? In certain mediums, like Bose - Einsten condensate, the speed of light can decrease to an order of meters per second. Is invariance principle valid for light in a medium? Or light will act just as a part from the body?
The principle of relativity states that c is invariant, Not as the speed of light but as a geometric property of space-time. Light in vacuum has a velocity of c, so its velocity will be invariant (it will be the same in all reference frames). In a medium, light has a velocity different from c, so it will not be invariant.
As I understand it, the speed of light is still c (it has to be), in a medium. The thing is, that if light is not moving through vacuum, it will run into particles, that will absorb the photon and then emit it from the other 'side', so the photon will move in the same direction. The time between the absorbtion and emission, although very small, makes the speed seem smaller, even though the photons are not moving slower then c.
Yes, and since atoms from the substance are moving with the reference frame light will become 'desorientated'. You says that "the photon will move in the same direction", interesting, directioin wrt what kind of coordinate system? Can I presume that he had the same direction wrt absolute space? If momentum of the photon do not changes during the absortion and emission process, there is no reason it direction to change!
I was just making sure everybody understood it. I didn't want anyone to think i was talking about reflecting light from a surface.
Fo3, allow me to correct your explanation a little to make it sound as it is in the Physics: "The thing is, that if light is moving through medium, it will be absorbed by the particles of medium, then re-emit by those particles, etc, etc. Although the time delay between the absorption and re-emission is very small, those processes make the speed of photons seem smaller, even though between interactions with particles of medium the photons are moving with the same speed c". In such form it is exactly what constitutes the theoretical base of whole physics of propagation of light into the media.
This post is addressed to the forum: Can you respond to the statement that the light in a moving medium will become disoriented? If a medium is spinning around some arbitrarily oriented axis as well as moving through space wrt some arbitrary reference frame at .9c will the exit trajectory of the light be co-linear with the trajecory of the light before entering the moving medium? To make the problem clearer let us assume that the medium is a flat circular diamond plate with radius 1 meter, 1 cm thick spinning around the axis of the plate at 100 rpm. A short burst of photons, say 10^-6 sec long, enters the edge of the plate perpendicular to the plate axis directed at the axis. The axis of the plate is moving along the trajectory of light at .5c away from the (case 1) and toward the beam (case 2) and any other arbitrary angle wrt the photon beam (case 3). What will be the trajectory of the beam after exiting from the spinning plate? I am not asking for an accurate calculation. A general dioscription will do? Geistkiesel
I was wondering, if and how can we talk about a photon, when the light is going from one medium to another, and changes its direction a bit. I know that the fraction of light is explained using an example with a lightbeam, but how does a single photon act?
I suppose that the regenerated light is a "different photon". If we use the standard model as described it assumes the newly emitted photon will move in the same direcion as the incoming photon which assume that the reemission process is momentum based. geistkiesel
Dear fo3, The answer is very simple: do you recall as the photons are passing screen with two small holes in it? Each photon goes randomly through one of hole, but the ensemble of photons (no matter is it completed from many gathered photons, or from many singled coming each after another) passes screen as ... a wave. The same with passing of any material piece...just as classic Physical and Geometrical Optics require. Keeping this my notice in mind, I am sure, you can answer your question ...by yourself.
As I understand it, a single photon will produce the interference pattern without other photons following; indicating that the single photon goes through both slits and interferes with itself. The spinning disk would be an interesting experiment. I can't guess the outcome.
Ha. I think it is an excellent question. I may even do that test (not using a 1 meter diamond of course). My expectation is that your hunch suggested here is that light will infact show some disorientation and become deflected as a function of the rotational velocity to the speed of light in the medium. I am unaware of any such test or observation and I could be wrong but I don't think so.
Me either at least not at the present, but look at the statement you made. "The photon interferes with itself". What can this mean? Feynman catagorized light coming in two types: 1) Horizontal polarized and 2) Vertical polarized. T This model suffers from an extreme case of unbelievability. Two kind of light were proposed to explain the observation of poalrization of the photons? But what if we have only one kind of light? Would this mean the light would be both H and V simultaneously? Absolutely not. The phopton would be, for a an instant an H then V then H then V etc. In other words the state generation of the photon is an intrinsic attribute of the photon. Whatever the current state happens to be upon "polarization" , that state becomes permanently the observed state while the other nonobserved is simply, nonlocal. A photon crashing diown upon a screen with two holes doesn't interfer with itself nor does the photon go into a "wave state", the photon enters a polarized state. However the polarization process does not turn the nonobserved state "off" like a light switch. The overly obvious reality regarding nonlocal force centers or entanglement processes is the physical fact of local /nonlocal force exchanges. The nonlocal attributes of an entity must have local/nonlocal interfaces in order that one affects the other. Otherwise, why even discuss entanglement and nonlocality? The passage through the holes is not as a wave. The local attribute iof he photon goes through one hole the nonlocal attribute goes through the other. While transitioning through the holes the local/nonlocal acitivty orders the photon vibration mode, or limits the mode as seen on the scintillation screen, the diffradtion pattern. This pattern is differentiated from a smudged pattern on the scinitllation screen with the diffraction pattern after transition through two holes. In the poalrized case some points on the screen are denied access to the photons. The polarization process lowers the photon entropy as demonstration of this affect. The local/nonlocal force exchanges during transition through the holes is a true and simplest action-at-a-distance (aaad) phenomenon AKA local/nolocal force exchanges. Interference, translated into the words of physical reality is the ordering of the photon vibration modes otherwise occuring randomly in space. Polarization determines the minmum state of equilibruium for the photon's projected or predicted future positon in space. The photon can take a limited and quantized number (8, 16 32 etc) of angles of exit from the hole detrermined by the current polarized state transition structure involving the erstwhile V and H attributes of the photon. The limited exit trajectory defines overall volumes of trajectories of any one two-hole experimental arrangement. There isn't any wave-particle duality, a model contrived to answer the enigmatic puzzle of two-hole diffraction quantum mechanically. Geistkiesel
Ok; Lets see; Here's one: from the Preface of Fundamental Problems in Quantum Theory, A conference held in honor of Professor John A Wheeler. Held at UMBC. I was there Please Register or Log in to view the hidden image! I've studied QM; it is just not my faith Please Register or Log in to view the hidden image!
Maybe so; that understanding came from a couple of hours of Google research beginning with "Single Photon interference" Yuriy: I've serfed your web site many times and find it very interesting. You seem capable of study in field theory as well as quantum theory; a rare talent that few people can muster. In your field theory expereience: Would a universe built only of vacuum fluctuations demand relativity phenomena in classic space-time? Most other scientists see that it would; you seem to think that it would not? I am interested to know your view. Vern
geistkiesel, Wow, your last post about light interference is really complicated, you seem to understand it very deep. I had always tought that this thing about a photon that interfere with itself is bullshit. I am trying to understand what you mean with my limited physics education... I know from QM that it is not nessecary photon to be simultaneosly wave and particle. If a photon is transmitted infinity number of times through the holes it will be produced probability distribution which corresponds to the interference patern, so the 'wave' only determines the 'future' of the photon, it most probable path, it is not a reality. The photon is all the time discrete particle. Anyway this is not conserned to the tooic, who started this debate about the light interference ..., oh ..yes... Yuriy. He very much likes to answers questions for one thread in another thread. Probably if we start a thread 'light interference', Yuriy will explain us the relativity in a medium... Your hypotetical experiment with the moving medium is just what I was woundering. I dont know about the rotation but the linear velocity of the diamond plate should not change the direction of photons, because (in my opinion) ohotons will remain with the same direstion WRT the Absolute space at the moment they had been emitted. While absorbed photons are in 'frozen' state inside the particle. The emitted photon is an exact copy of the absorbed. So the light should 'bend' in the direction of Earth move around the Sun, and if its velocity is really slow it should be noticeable even with a simple eye... (Please, don't be too strict about my physics understandings, after all I had received education in a third world country, compared to my lectors Yuriy would seems as a genious...,)
