Category Archives: reflection

Quantum Weirdness – A Matter of Relativity? Part 4

Quantum Weirdness

A Matter of Relativity?

Copyright 2006/2007 James A. Tabb  

Part 4: Photons that hit tilted glass

Individual photons directed at tilted glass have an option of being reflected or going through. They can’t do both because they can’t be divided, or so we are told. Yet some experiments seem to imply that they sometimes take both paths unless a detector is in place. It is my thought that the foreshortened world of the photon explains this phenomenon too  

  

       

 

  

Photons on tilted glass  

Figure 9:  Photons on tilted glass

 

Relativity at Wor

Because the photon is moving at the speed of light, the entire path from emission to destruction has zero length and zero time passage.   Time and space are both warped while it is in flight.   It does not matter what we measure or calculate.   The entire experimental assembly is to the photon like a flat surface with all the options congruent to the front surface, that surface being stuck to the point of its emission, and shrunk to zero thickness, glass, air paths, mirrors and all. All the open paths are the same length (zero) to the photon, regardless of how we measure them.   

   

If a detector is in place, it is in the way immediately, independently of distances and times as we measure them. The photon is instantaneously (from a relativistic perspective) connected to the screen by all optional paths that lead to the same points, and the photon separates without breaking until it begins to meld together somewhere. Otherwise it takes one path or another and still gets where it is going.   

There is an argument that the photon must go through the glass whole since the photons transmitted through the glass are actually retransmissions within the glass, not the same photon that impacts it. That argument then says that the other path has to either have had no photon or a whole one also (creation of energy not allowed). It also says that the photon must retain a whole packet of energy.   

My argument is that the entire path, including the glass and the remaining path through the experiment all the way to a recombination point is impossibly thin to the photon at the time it hits it.   There is no separation because the paths are zero distance apart.  This argument also avoids the messy retransmissions within the glass argument, as they are not necessary.  

It can then “feel’ itself through this very thin apparatus. It is thus capable of separating into two paths that recombine at the proper point before the photon separates at the surface of the glass. This keeps the photon whole and yet allows it to take multiple paths.  

Our perspective seems to be that the flight path is of finite duration and the paths seem to be of vastly different lengths. Thus we don’t always understand what is happening. The photon could care less about our perspective – it is working within a highly warped time and space and we are not.  If it finds a way to recombine without violating its energy conservation directive, it will do so even if a portion of it separates at the glass, wraps around the various mirrors and recombines with a portion that is passing through the glass. That is ok since the total distance of its flat world is still zero and the physical recombination takes place before the physical separation takes place.  United they move!   

The experimental apparatus grows as the photon passes through it.  Those parts in front of the photon are still stuck to its nose and of zero remaining depth.  Those parts to each side of the photon have normal depth and structure.  Those it has passed are invisible and forever behind it, vanished.   When it hits a glass surface, all the paths in front of and also along its reflected paths are plastered as if congruent.  Thus all open paths are available at that instant.  If any are closed, then those paths are not available for passage.     

Even where a detector is switched in (from our perspective) after it passes through the glass, it is a closed path to the photon at the glass surface because the entire path has zero depth the instant it is emitted due to the photon being at c throughout its entire path.   Indeed the path with the detector is closed when it is emitted, as all the paths are of zero depth the instant emitted, even if the photon is switched in at some later time (from our perspective).   Relativistic foreshortening is instantaneous to an object running at c.  This is all taking place in a space-time warp where length is zero, time is zero for the photon’s flight but not for us, the stationary observers!  

The difficult thing to wrap our minds around is the fact that the instant the photon is emitted, whether on a distant star, or on a filiment within our laboratory, the entire path that it takes occurs at the same instant of time throughout its path, birth, flight, death – all instantaneous to the photon (no matter what happens within that path in our “normal world” time-frame) .   If a detector is absent at the instant the photon is emitted and then switched in later before it arrives (from our normal world perspective), the photon is fully affected at the instant of emission (from a relativistic world perspective) as if it had been there the whole time, and thus the outcome is determined at that instant, not when we think it has passed.   It cannot be fooled.  

It is all a matter of relativity 

Next:  Entangled particle weirdness explained.

 

Quantum Weirdness for Tilted Glass

  Photons That Hit Tilted Glass

Individual photons directed at tilted glass have an option of being reflected or going through.  They can’t do both because they can’t be divided, or so we are told.  Yet some experiments seem to imply that they sometimes take both paths unless a detector is in place. 

Tilted GlassTilted glass acts like a sort of beam splitter.  It either goes through or bounces off  (or sometimes absorbed). 

QED can easily compute the probability dependent on the angle.  Some go through and some reflect and the angle makes the difference.  You can adjust the angle to get a 50-50 chance of reflect or go through.   

If you use other beam splitters to put the two beams back together you can get an interference pattern, not unlike the one depicted in the double slit experiment.   The beam goes both ways, but one path is longer and so when they come back together, they interfere with each other.

However, if you turn the light down so only one photon at a time goes through you still see the same effect, implying the photons go both ways.   If you leave the single-photon-at-a-time beam on long enough and have a good film in an exceptionally dark room, the outcome will be a well defined interference pattern. 

How can single photons being emitted minutes apart interfere with each other?   How can a photon that can only go one way or the other interfere with itself?   QED cannot explain this quantum weirdness for single photons.  It can predict the pattern but cannot explain it.  Every indication is that when no detectors are present, the individual photons somehow split.

There are some very sophisticated delayed choice experiments involving beam splitters.  There are super fast detectors that can be switched into the photon beam after it goes through the splitter. In other words, spit a photon at the splitter, calculate when it reaches it (about 1 nanosecond per foot of travel) and then switch the detector into the path behind the splitter.

The idea is to try to trick the photon into “thinking” there is no detector so it is ok to split, then turning on the detector at the last moment and try to catch the photon doing something it is not supposed to do, breaking laws along the way.  If it arrived at a detector in the reflected path and was also seen by the detector behind the splitter, some law has been broken and the mystery solved – figure out a new law. You do this randomly. If the photon goes both ways, it can be caught by the detectors.   It never does.

The physics says that if you try to make the measurement, it will disturb the experiment. And so every test seems to verify that fact. Whenever a detector is present there is no interference pattern. Whenever the detector is absent, the pattern reappears.

There is an argument that the photon must go through the glass whole since the photons transmitted through the glass are actually retransmissions within the glass, not the same photon that impacts it.  That argument then says that the other path has to either have had no photon or a whole one also (creation of energy not allowed).   It also says that the photon must retain a whole packet of energy.   Yet single photons seem to interfere with each other.  QED cannot explain why.   I hope to do so.

Next:  Entangled Particles

Quantum Weirdness in Glass

  Perfect Transmission

One of the weird aspects of photons involves reflection from glass of varying thickness.  Send a laser pointer beam perpendicular to a pane of glass and about 4% of it will reflect back, on average, but, by carefully selecting glass of various thicknesses, the reflections vary from 0% to 16%.    Glass a foot thick can be slightly adjusted in thickness to not reflect at all!   All the light goes into the glass – perfect transmission. 

 QED easily shows how this works for light beams.   Rays from the back of the glass interfere with the rays coming in the front so as to cancel the reflection if the wavelength is a multiple of ½ wavelength.

However, the cancellation at ½ wavelength also works for individual photons for thick glass, and there seems to be no answer other than “quantum weirdness”.    QED cannot explain it for single photons.

Photon on Glass

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How does an individual photon know how thick the glass is the instant it hits the front surface when the back surface is thousands of wavelengths away?   The reflected photon would be six feet away before a copy could make a round trip through a foot thick piece of glass.  (Two feet round trip at 1/3 speed of light in air).

The photon has a number of options to reflect.  It can reflect at the front surface of the glass,  the back surface, somewhere within the glass, be absorbed or go on through.  The reflected and absorbed cases mean it does not exit the other side, and the latter one means it does exit.  

If the glass is exactly the right thickness, it does not reflect and shoots right through.   The rub is this: a photon that reflects off the front surface of a foot thick piece of glass has to make that decision at the front surface before it goes in.   As soon as it hits that surface, it begins to move away in the other direction.  The probability for reflection depends on the thickness of the glass.  However, the photon cannot know the thickness in advace.  Or can it?  I have a theory that tells how this works.

This is only one of the glass problems.   Next I will tell you about the weird effects for photons that hit tilted glass