Photons seeing the future?

So if we exclude "time travel" as a valid explanation, then would that suggest that we yet do not understand the means by which the phenomenon results? Perhaps it suggests a yet unobserved connection that, although we observe what appears to be a communication from point to point in space that there is yet some continuity between said points that persists even after the apparent transfer of energy. But I suppose that would still infer a zero time communication, which is not allowed, though in this case it would be from the past. Maybe there is some issue regarding our notion of the nature of displacement that yet has not been discovered. If there were a dual nature to the idea of what constitutes space that would allow such a continuity without violating the speed of light? Actually just earlier today I had been thinking of a question I wanted to ask you Jorrie. Does the phenomenon of gravity result in a reduction of mass at the rate of E=MC^2. Seems like it is energy and must therefore come from somewhere.

Hi rcapper, interesting thoughts!

You asked: "Does the phenomenon of gravity result in a reduction of mass at the rate of E=MC^2. Seems like it is energy and must therefore come from somewhere."

Gravity per se is not energy, it is caused by concentrated energy, I think. If the shape of that concentration of energy changes, it transmits energy in the form of gravitational waves. A pair of dumbbells rotating end over end radiates some of its mass energy away as gravitational waves, but it is minuscule. Two massive orbiting bodies radiate some of their orbital energy away as gravitational waves and eventually fall into each other.

However, just like in the case of a magnetic field, the gravitational field can interact with things moving through the field and that may exchange energy between the bodies.

J

OK, mass distorts the shape of space around itself. So is this phenomenon for free? Doesn't it constitute an expenditure of energy? In fact, since I suppose mass is a phenomenon of energy then wouldn't it be reasonable to expect that the maintenance of such phenomena require the expenditure of that same energy from which the phenomena springs? No free lunch, why not no free mass, no free gravity and so on. It may be an odd thought but it just seems to me that the piper must be paid.

OK, I'll stick my neck out...

Gravity is a force, just like an electrostatic field around an electron is a force, just like a magnetic field around a magnet is a force. But a force is not energy. For energy with regard to a force to exist, work has to be done in relation to the force. So, if you move a massive body, the energy you impart to the object is converted to energy through changes in the gravitational force, thus giving off some of its kinetic energy (which you gave it) through gravitational waves.

Jorrie, any comments?

Hi vermin, Bingo!

One can say that the energy of the total gravitational field is locked up in the total energy of the object causing the gravitational field.

In fact one reason why Newton's gravitation fails in strong fields is that the gravitational field itself has "energy" and gravitates!

-J

Certainly I understand the classic definition of work and I understand that a static force does no work. However, E=MC^2 tells me that there is energy present in matter and phenomenon of matter such as gravity and magnetism, well if it those are not forms of energy, just as matter itself is then doesn't the work "force" in the context of "not energy" imply spooky magic? I guess in trying to think outside the box I have always felt there was something wrong with the idea that we try to pretend that we understand better than we do certain phenomenon by saying what it isn't or giving it ambiguous labels. Seems like I recall reading a definition of magnetism once that said something to the effect of "imaginary lines of force that act at a distance". I'm sorry, I don't buy the imaginary part. Until we are definitively certain what it is, I don't think we can really say what it isn't. I agree that that which is static does no classical work. I don't believe that something I can feel and push against does not constitute a form of energy.

Hi rcapper, you wrote: "However, E=MC^2 tells me that there is energy present in matter and phenomenon of matter such as gravity and magnetism"

I gave my view in a reply to "vermin" (#15), which concurs with your statement. Just about everything we can imagine is energy, even imagination!(?)

-J

Thanks Jorrie, I appreciate your comments. I think the question of whether imagination (or even information) is energy or not is one of those ones we may not be able to answer in a way that does not constitute a philosophical debate. It certainly requires energy to manifest but it seems that "it" is more a specific ordering of energy and does that constitute additional energy. Perhaps it is a separate phenomenon that encodes energy without actually being energy. But can something be, without being energy. The same quantity of energy could exist in a random ordering without information. And without a human observer would be no different? I have thoughts, yet I am not the thought. I suppose this could ultimately lead to the question "What is life?" and about the only perhaps unique observation I would have there would be the opinion that life is anti-entropic. Life takes things in lower state of organization and moves them into a state of higher organization. Of course again that is from a reference frame of being alive and could constitute a circular reference. "I think, therefore I am, I think..." I think my brain is starting to hurt again.

If you walk up a hill, the energy is stored somewhere, and you get it back when you walk down the other side. If this energy has mass, does the earth increase slightly in mass, or do you, or does the gravitational field have some mass associated with it?

Light travels faster than the speed of light. That's why we end up wagging the dog.

John

Maybe I'm missing something here, but it seems to me that perhaps the second beam splitter is 'telling' the electrons how to display themselves. Maybe the electrons somehow carry with them information about their path (or all possible paths) and behave accordingly to the presence (or nonpresence) of the second beamsplitter as they encounter it (or not). No time travel or faster than light information needed.

Hi SkFarmer, you wrote: "... perhaps the second beam splitter is 'telling' the electrons how to display themselves."

If the green splitter is not there, only one of the detectors "see" a photon at a time, proving that the photon has taken the one or the other path at random. It behaves like a particle, with no interference pattern being build up.

If the green splitter is inserted after the photon is already on its way along one path, interference patterns build up on both detectors, as if the photon divided into two halves and followed both paths.

The problem is: how can the photon know it must (or must not) split into two at the blue splitter, before the decision is even made as to whether the green splitter will be there or not?

If the photon carries information with it on the path (which it probably does), it must always follow all possible paths! So how come it follows only one path if the green splitter is not there?

Suppose the green splitter is there and the photon follows both paths, but just before it reaches the green splitter it is yanked out of the way. How can it now decide to follow only one path?

I can feel a splitting headache coming...

J

Perhaps it always travels as a wave. The first beam splitter spreads the wave and when the path is unimpeded by the second splitter the wave collapses in one location or the other. Perhaps causing the wave to interact in a second medium after the initial spreading creates the interference. I wonder how precise are the optics and their positions. I wonder if there would be the same effect if the experiment could be done with some of the new negative coefficient of refraction optical materials. Ouch, my brain is starting to hurt now.

I have to agree. It seems to me that the photon always travels as a wave and thus always follows all possible paths. It is only at the point of detection that the photon must 'behave' as a particle or as a wave.

So, when the second beam splitter is not there and only one detector 'sees' the photon it does NOT prove that the photon took only one path (it actually took both paths). It only proves that when you can determine which path the photon APPEARED to take, it will behave as though it took one path like a particle would do. It seems as though the photon can tell if you can determine its apparent path when it is detected. How or why it does this is way beyond my understanding.

So, if the second beam splitter could be pulled out of the path just before the photon hits it, the photon would behave as though the beam splitter was never there. It did not decide whether it should interfere or not at the first beamsplitter based on some 'knowledge' of the presence of the second beam splitter, it only reacted to all of the elements and/or possible paths it encountered on its way to the detector.

How do you release a single photon? Supposing they only come in pairs like shoes?

Just a thought ... If time slows down as one approaches light speed, for a photon time is stopped and the entire history of the universe happens at once. So the photon (in its reference) encounters the second beam splitter "at the same time". Would this delayed choice work with particles such as a beam of neutrons that move slower than light speed?

Hi Jorrie,

I had similar experiments described in my Quantum Mysteries series especially Part 5. There is a short explanation in my forum thread "History of Light" (maybe too short). This explanation does not require anything to move faster than light. If you have not read the book that I recommended in part 5, then I suggest you do.

S

This is because there is no such thing as an absolute "now" for subatomic particles and photons. They all exist over a span of time - part of their mass is in the past and part is in the future. When the wave nature of an electron is observed it's because we're observing the electron smeared out over time. And when we see a photon act as a particle, it's because we're not looking at the photon in a way that exposes its "smeared out in time" properties. This time displacement also affects particles with respect to their spins.

So to put it another way, no quantum level particle exists in one exact point in time. Some of it exists in the future and some in the past and all points in between. Of course, this time displacement is dependent on the energy of the particle. The higher the energy, the less the displacement.

Huh? Huh?

Hi vermin, you wrote: "So to put it another way, no quantum level particle exists in one exact point in time. Some of it exists in the future and some in the past and all points in between."

I'm guessing when it comes to quantum physics.

I think the central mystery (Feynman's "only mystery") remains. We could in principle place the two detectors light-years apart. So the probability wave must collapse in an non-causal way (instantaneously over great distances). In the case of electrons that cannot move at the speed of light, this is even more difficult to comprehend!

"Of course, this time displacement is dependent on the energy of the particle. The higher the energy, the less the displacement."

I'm not qualified to comment, but it sound suspicious to me!

-J

Just as position and momentum are interconnected in quantum physics, so time and energy are connected - this much is not my theory. Quantum physics has relied on both of these entanglement-like relationships for many years. Check it out.

I think the beam spliters are litterally splitting the photon in two. The first beam splitter is splitting the origional photon into two photons of opposite polarization. One is then reflected by one mirror while the other is absorbed by the other mirror. This is because one mirror reflects to the left while the other reflects to the right. Only one dectector sees a photon. When the second beam splitter is up, it splits the one photon that reaches it into another two photons causing both detectors to see photons.