Photon 'afterglow' could transmit information without transmitting energy

March 31, 2015 by Lisa Zyga, Phys.org feature

Spacetime diagram of the scientists’ proposed set-up, where the dotted lines indicate the first and last light rays emanating from Alice. Although no energy is transmitted, the receiver (Bob) must provide the energy needed to detect the incoming signal. Credit: Jonsson, et al. ©2015 American Physical Society
(Phys.org)—Physicists have theoretically shown that it is possible to transmit information from one location to another without transmitting energy. Instead of using real photons, which always carry energy, the technique uses a small, newly predicted quantum afterglow of virtual photons that do not need to carry energy. Although no energy is transmitted, the receiver must provide the energy needed to detect the incoming signal—similar to the way that an individual must pay to receive a collect call.

The physicists, Robert H. Jonsson, Eduardo Martín-Martínez, and Achim Kempf, at the University of Waterloo (Martín-Martínez and Kempf are also with the Perimeter Institute), have published a paper on the concept in a recent issue of Physical Review Letters.

Currently, any protocol also involves transmission. This is because these protocols use real photons to transmit information, and all real photons carry energy, so the information and energy are inherently intertwined.

Most of the time when we talk about electromagnetic fields and photons, we are talking about real photons. The that reaches our eyes, for example, consists only of real photons, which carry both information and energy. However, all contain not only real photons, but also virtual photons, which can be thought of as "imprints on the quantum vacuum." The new discovery shows that, in certain circumstances, virtual photons that do not carry energy can be used to transmit information.

The physicists showed how to achieve this energy-less information transmission by doing two things:

"First, we use quantum antennas, i.e., antennas that are in a quantum superposition of states," Kempf told Phys.org. "For example, with current quantum optics technology, atoms can be used as such antennas. Secondly, we use the fact that, when real photons are emitted (and propagate at the speed of light), the photons leave a small afterglow of virtual photons that propagate slower than light. This afterglow does not carry energy (in contrast to real photons), but it does carry information about the event that generated the light. Receivers can 'tap' into that afterglow, spending energy to recover information about light that passed by a long time ago."

The proposed protocol has another somewhat unusual requirement: it can only take place in spacetimes with dimensions in which virtual photons can travel slower than the speed of light. For instance, the afterglow would not occur in our 3+1 dimensional spacetime if spacetime were completely flat. However, our spacetime does have some curvature, and that makes the afterglow possible.

These ideas also have implications for cosmology. In a paper to be published in a future issue of Physical Review Letters, Martín-Martínez and collaborators A. Blasco, L. Garay, and M. Martin-Benito have investigated these implications.

"In that work, it is shown that the afterglow of events that happened in the early Universe carries more information than the light that reaches us from those events," Martín-Martínez said. "This is surprising because, up until now, it has been believed that real quanta, such as real photons of light, are the only carriers of from the early Universe."

The new protocol could also have practical applications for quantum communication technology.

"The also occurs in flat spacetime of dimensions other than 3+1," Jonsson said. "It occurs, in particular, in the case where there is only one spatial dimension, such as is effectively the case in an optical fiber. We are currently investigating applications of our results to quantum communication through optical fibers."

Explore further: Confirming Einstein, scientists find 'spacetime foam' not slowing down photons from faraway gamma-ray burst (Update)

More information: Robert H. Jonsson, et al. "Information Transmission Without Energy Exchange." Physical Review Letters. DOI: 10.1103/PhysRevLett.114.110505

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derphys
5 / 5 (7) Mar 31, 2015
more clear the abstract :
We show that it is possible to use a massless field in the vacuum to communicate in such a way that the signal travels arbitrarily slower than the speed of light and such that no energy is transmitted from the sender to the receiver. Instead, the receiver has to supply a signal-dependent amount of work to switch his detector on and off. This type of communication is related to Casimir-like interactions, and it is made possible by dimension—and curvature—dependent subtleties of Huygens' principle.
JVK
1.2 / 5 (18) Mar 31, 2015
Excerpt: "...up until now, it has been believed that real quanta, such as real photons of light, are the only carriers of information from the early Universe."

There is a clear link from the light-induced de novo creation of amino acids to their anti-entropic epigenetic effect on cell type differentiation in plants and animals. Cell type differentiation is controlled by the biophysically constrained chemistry of RNA-mediated amino acid substitutions and protein folding.

Inventing a theory of information transfer sans energy transfer is required now that serious scientists have focused on the fact that "Life is physics and chemistry and communication" http://dx.doi.org...as.12570

Pseudoscientists are forced to fight against the facts by inventing new theories that disassociate energy and information.

But see: Scientific method: Defend the integrity of physics http://www.nature...-1.16535
JVK
1.3 / 5 (16) Mar 31, 2015
"...a very small number of individuals, say two or three in tens of thousands, turn up with small but 'jump-like' changes, the expression 'jump-like' not meaning that the change is so very considerable, but that there is a discontinuity inasmuch as there are no intermediate forms between the unchanged and the few changed. De Vries called that a mutation. The significant fact is the discontinuity. It reminds a physicist of quantum theory -no intermediate energies occurring between two neighbouring energy levels. He would be inclined to call de Vries's mutation theory, figuratively, the quantum theory of biology. We shall see later that this is much more than figurative. The mutations are actually due to quantum jumps in the gene molecule"(p. 33-34) http://www.amazon...07604664

Theorists must now change the definition of mutation to break the link between energy and information.
super
5 / 5 (2) Mar 31, 2015
Does this allow one to see arbitrarily far back in time? Where?
antialias_physorg
5 / 5 (3) Mar 31, 2015
Does this allow one to see arbitrarily far back in time?

No, since you still need to emit a photon for this (though the photon doesn't hit the receiver...which is the awesomely quirky bit, here).
shavera
3.7 / 5 (3) Mar 31, 2015
super: no. This would still require a mechanism designed to send a message in this style, in addition to a receiver to detect it. Not every physical process will generate a message in this manner.
Sean_W
5 / 5 (2) Mar 31, 2015
So do the virtual photons behave like the real ones or can you shield the real ones to allow the virtual ones to continue further than the real ones?
antialias_physorg
5 / 5 (9) Mar 31, 2015
So do the virtual photons behave like the real ones or can you shield the real ones to allow the virtual ones to continue further than the real ones?

The virtual ones originate along the path of the photon - but can be detected elsewhere (which is the point of the article. The photon doesn't hit the receiver, but the receiver can pick up the virtual photons elsewhere)

I'm not sure if the virtual photons allow an evesdropping on the state of the photon (which, if possible, would mean that quantum cryptography has just been broken)
derphys
5 / 5 (7) Mar 31, 2015
the prellminary paper :
http://arxiv.org/...5.3988v3
The conclusion is more clear :
"In our scenario, Alice is modulating the Casimir-Polder effect that arises
from Bob's local interaction with the field."
In our nearly flat 3D world this vacuum interaction ( for very short distances, identical to Van der Waals interaction ) decreases fast with distance so that it seems not useful.

Nevertheless, this opens some hope to obtain somme information from far away domains of our universe not visible with light but nevertheless coupled to our quantum vacuum.
derphys
5 / 5 (2) Mar 31, 2015
A similar real experiment "measuring the internal state of a single atom without energy exchange" :
http://www.lkb.en...?lang=en
JVK
1 / 5 (11) Mar 31, 2015
Attempts to exempt speculative theories of the Universe from experimental verification undermine science, argue George Ellis and Joe Silk.
http://www.nature...-1.16535

Has everyone decided to ignore that fact?

I'm not sure if the virtual photons allow an evesdropping on the state of the photon (which, if possible, would mean that quantum cryptography has just been broken)


Not too hard to break when all it takes is another theory.

LagomorphZero
not rated yet Mar 31, 2015
It would be interesting to try and scale this up into a telescope, it could possibly see beyond the CMBR or even the visible universe. My only concern is that the article did say it needed a well curved spacetime to work properly, so it may not work at astronomic scales.
derphys
5 / 5 (2) Mar 31, 2015
Not another imaginary theory but real working experiment :
http://www.lkb.en...?lang=en
real experiment "measuring the internal state of a single atom without energy exchange"
And Casimir interaction is real; as real as Van des Waals interaction which becomes Casimir on long distances with retardation effects.
OdinsAcolyte
5 / 5 (1) Mar 31, 2015
so light leaves tracks.
This opens the door to many implications.
barakn
2.3 / 5 (3) Mar 31, 2015
.. the afterglow would not occur in our 3+1 dimensional spacetime if spacetime were completely flat. However, our spacetime does have some curvature, and that makes the afterglow possible.
Gravity is a curvature of spacetime, so the afterglow will be made in locations where we already observe the light path being strongly bent: gravitational lenses.
baudrunner
1 / 5 (1) Mar 31, 2015
super: no. This would still require a mechanism designed to send a message in this style, in addition to a receiver to detect it. Not every physical process will generate a message in this manner.
It is tempting to disagree with this. The messages have already been sent and are still modulated over infinity on the particles in the particle medium. What the article states in part is that an input of energy is required to retrieve the information.

This energy would be a photonic reference wave resonating with the source energies of a stored event as it then was. Tricky, but not impossible. We could conceivably be a witness to history in some form.
mitul
5 / 5 (2) Mar 31, 2015
That implies to me as if the information is actually shared between photons and the afterglow virtual photons. If so, does that mean the information we receive via photons is partial?
baudrunner
1 / 5 (2) Mar 31, 2015
If so, does that mean the information we receive via photons is partial?
It means that the information we receive is immediate and contextual. We extrapolate the information using the current frame of reference. We demodulate the information that we expect to receive, and normally make no effort to disclose what isn't obvious.
baudrunner
1 / 5 (2) Mar 31, 2015
I Can't see this being even remotely possible.
These guys here would take issue with that: https://indico.in...es/0.pdf
TheGhostofOtto1923
2.3 / 5 (3) Mar 31, 2015
Is this only true for photons or could other particles do this? Could we read their states without collapsing them and thereby defeat the uncertainty principle?
JVK
1 / 5 (7) Mar 31, 2015
Casimir interaction is real; as real as Van des Waals interaction which becomes Casimir on long distances with retardation effects.


You seem to be claiming that Ellis and Silk (2014) are wrong in "Scientific method: Defend the integrity of physics"

Why do you think they claimed "...the issue boils down to clarifying one question: what potential observational or experimental evidence is there that would persuade you that the theory is wrong and lead you to abandoning it? If there is none, it is not a scientific theory."

Casimir interaction is real; as real as Van des Waals interaction which becomes Casimir on long distances with retardation effects.


Was any observational or experimental evidence offered that suggests these theories are wrong? All discussion comments seem to be opinion-based and/or to add theories.
jeffensley
1 / 5 (1) Mar 31, 2015
Hard to wrap my brain around this one. In a vacuum (ie no matter) a photon passes through leaving an imprint and/or affecting... nothing? Whether I understand it entirely or not, I still get the impression that a real photon has to pass by first, suggesting that this is not truly energy-less.
MandoZink
5 / 5 (1) Mar 31, 2015
This is difficult for me to conceive. Virtual photons are random moving, short-lived, disturbances in an electromagnetic field with non-fixed energy levels that decline as the disturbance diminishes. Not much there to work with.

rufusgwarren
not rated yet Mar 31, 2015
We only see a near field to a given percent of validity. Consider a 4 dimensional space, each dimension is either time or space; i.e. pick and arbitrary space-time dependent constant as the definition of space and time, lambda nu = c, to map to each dimension. Then also know that w = c * Lambda Observed divided by Lambda Emitted as the speed of the envelope, or the velocity of the object defined by its poynting vector evolution through space time. Pick your degree of precision based only upon the measurement and possible instrumentation; don't forget the sign.
rufusgwarren
not rated yet Mar 31, 2015
You should be able to see resonant points based upon any w. The trick is the mod/demod. But first the existing field must be properly defined and to note the emitted velocity of the wave front, must also be verified, but assume it always as c. Hence a reference. The particle space are the present near field, i.e. we see them spatially, and no idea of the frequency domain invisibility simply as a function of capability, i.e amplitude response of the equipment and the sense impedance of this field. Using multiple instruments to compute the most likely event as moving back-ward in time or forward in time. These old fields, just don't want to see too many moving toward me, I would expect a certain flow of the entire field of "mass" envelope. But what if my acceleration is within this flow may be deduced And mass only a function e+ and e-. But first I need to see which are moving away, or toward me correctly, which defines my direction within the space is a simple supposition
ab3a
5 / 5 (3) Mar 31, 2015
I'm missing something: If a photon is quantized light, how can there be "afterglow?"

rufusgwarren
not rated yet Mar 31, 2015
Sweep the entire field with our movement relative to the sun somewhere near zero, or maybe, relative to another system, but using all the information. How close will we get if we translate the + and - and as it's expected directional vector is relative to and unknown vector spot of the entire flow such that it follows gravitationally, i.e. separation and existing motion as possible by the field. I expect there may exist the same sort of activity as QM. Reality becomes wider and wider, select one. It's only information. You can see future events relative that distant point, and deliver information, instantly. How many events exist waiting around to be ID'd in a certain space time, forget what can exist, this is a filter.
Pavel F
5 / 5 (2) Mar 31, 2015
For JVK: but de Vries is a vitalist and hence really NOT taken seriously at all by the main-stream orthodoxy. I see here some trend towards vindication of Rupert Sheldrake's theories...which would mean only this: heresy of yesterday becomes orthodoxy of tomorrow, or in other words: do not take science too seriously (that it is telling "the truth") but instead rejoice in the marvelous universe we are living in and as children try to find out our own way.
rufusgwarren
not rated yet Mar 31, 2015


I'm missing something: If a photon is quantized light, how can there be "afterglow?"


A photon is a field event, a particle is + or - and radiates a field; thus, particles may look like fields because the fields produced by the particle are actually fields not particles. Pretty obvious mis understanding in physics, similar slit results because it's the same experiment, It's obvious they share same energy, but ...
JVK
1 / 5 (6) Mar 31, 2015
Thanks Pavel F.

De Vries and other vitalists have since linked the light-induced de novo creation of amino acids to substitutions that differentiate the cell types of all genera via anti-entropic effects on viruses.

Rupert Sheldrake Interview http://www.thebes...terview/

His "Self-organizing systems include atoms, molecules, cells, organs, organisms..." My model shows that nothing is self-organized.

Nutrient-dependent pheromone-controlled ecological adaptations: from atoms to ecosystems
http://figshare.c...s/994281

As children, we should not again be led to believe in the latest most ridiculous theory of all at a time when serious scientists are linking information from the sun via transmission of its energy to all cell types in all genera in the context of the biophysically constrained chemistry of protein folding.
rufusgwarren
not rated yet Mar 31, 2015
Imagine placing or removing something from a field moving past you at an infinite speed, the only way the two of you, the wavefront, the wave, harmonics, may exist is to be harmless, that would be a definitive state. Does it or does it not exist? Simply because we are is not conclusive unless this is demonstrable. Hence the definition of the wake may be transmitted within these fields begin to make sense, but you can only affect any measurement with or without energy transfer is the real question? Also the event at creation, is it spatially spherical and temporally bounded? i.e. not as a source?
DarkLordKelvin
4 / 5 (8) Mar 31, 2015
"Secondly, we use the fact that, when real photons are emitted (and propagate at the speed of light), the photons leave a small afterglow of virtual photons that propagate slower than light. This afterglow does not carry energy (in contrast to real photons), but it does carry information about the event that generated the light. Receivers can 'tap' into that afterglow, spending energy to recover information about light that passed by a long time ago."

So basically, these guys engaged in some mathematical exercises that convinced them that photons have a detectable "exhaust trail"? Please pardon me if I wait for the experimental confirmation before buying into this particular theory. Also, I can't put my finger on it yet, but it seems like there must me some sort of violation of a conservation principle involved here. It's hard to see how a photon moving through space creates an unspecified amount of "virtual information" that can be arbitrarily "read out" at will by an observer.
rufusgwarren
not rated yet Mar 31, 2015
Hence, the definition of locality, within a four dimensional space must comply. However, the four dimensional space may not even be stable, but you must define the scale of this measurement, i.e. causality.
DarkLordKelvin
4 / 5 (8) Mar 31, 2015
Is this only true for photons or could other particles do this?


Seems like it ought to be true for other massless "force carrier" particles at the very least. Massive particles can't ever reach c, and they seem pretty explicit that the light-speed of the photon is an important aspect of their theory, but I haven't read the paper yet, so maybe I am inferring too much.

Could we read their states without collapsing them and thereby defeat the uncertainty principle?
Well, if that were ever demonstrated, it would mean QM is not a valid theory, so I wouldn't hold my breath. It's kind of like the 2nd law of thermodynamics; if you ever think you have experimental proof of its violation, first, don't tell anyone you think that, then figure out what you have done wrong.
rufusgwarren
not rated yet Mar 31, 2015
Mass is a definition for the number of particles and formations; however, a collective relative to another collective does obey the inverse square law, and is always attractive, charge, even superimposed, must comply; however, the speed of a body can exist from +/- infinity as so the wave-front. Hoping our position in this flow has not reached that point. Anyway, the point would probably be singular, (no pun intended), but others may exist. If we knew how to take and translate measurements, with regard that other methods may be correct. By the way, at least one point, as such, must exist.
MandoZink
5 / 5 (2) Mar 31, 2015
It's obvious they share same energy, but ...

A fundamental (real) particle is a stable ripple of contained energy on a field. Particles are resonances, virtual particles are not. The energy of a "virtual particle" is arbitrary and fleeting. It is a non-quantized disturbance in the field.
rufusgwarren
not rated yet Mar 31, 2015
It's obvious they share same energy, but ...

A fundamental (real) particle is a stable ripple of contained energy on a field. Particles are resonances, virtual particles are not. The energy of a "virtual particle" is arbitrary and fleeting. It is a non-quantized disturbance in the field.

Depends, if everything relative to you is affected by you or you are the effect of everything happening. Simple temporal state space equation should define this. Whats the source for a gain media? are you an affect or an effect?
rufusgwarren
not rated yet Mar 31, 2015
So defining a particle not as an "effect" but as an actual Function "affects" removed. And what is left-over is simply not explained, i.e. known physics + a guess. I would like to analyzed a spectrum that is underivable from a set of particles within known certainties without looking for a "guess", oh, I'm getting off the track, i'm having visions of a Higgs field that makes about as much since as the accompanying gluons. An EM wave is not a particle but a result of relative particle motion. Field events may be constructed, especially in high energy dynamics. ugh.. particles and waves, interpretation gives me the willies.
antialias_physorg
5 / 5 (1) Apr 01, 2015
but it seems like there must me some sort of violation of a conservation principle involved here.

The way I read it there is no conservation violated. Virtual particles operate in pairs. And they specifically state that the energy to detect them must be added at the receiver side. So there is no energy being 'left behind' by the photon in the afterglow (also specifically stated in the article when they talk about information transmission without energy being transmitted)

The 'conservation of information' is an interesting aspect,here. Either the virtual particles clone the information (i.e. information conservation is not a conservation law) or their measurement affects the photon via 'spooky action' to lessen its information content (i.e. the virtual photons are 'entagled' with the producing photons).
antialias_physorg
5 / 5 (5) Apr 01, 2015
OK..after reading into the paper (thanks derphys for the link) it seems that conservation of information could indeed be violated as they state:
" arbitrarily many spacelike separated receivers
could be arranged in the future lightcone of Alice, such
that all receive the same signalling contribution to Pe(t)"

I'm not able to check the math on this, but if true then that's a pretty significant finding.
JVK
1 / 5 (5) Apr 01, 2015
http://phys.org/n...tic.html

This news links the sun's biophotonic biological energy and the viral microRNA / nutrient-dependent microRNA balance from the microRNA/messenger RNA balance to RNA-mediated amino acid substitutions and cell type differentiation in all genera via the biophysically constrained chemistry of their nutrient-dependent RNA-mediated protein folding.

See also: NIH's Collins on Changing the Future of Medicine http://www.medsca...=26197EY

Alternatively, stay focussed on ridiculous theories that separate energy and information to avoid the obvious link to biologically based top-down causation
DarkLordKelvin
3.7 / 5 (6) Apr 01, 2015
Complete misunderstanding of how photons are created from excited materials. What they are seeing is more than one photon from an event.


Well, it's just a theoretical prediction at this point, so I don't think that's an issue.
DarkLordKelvin
3.7 / 5 (6) Apr 01, 2015
The 'conservation of information' is an interesting aspect,here. Either the virtual particles clone the information (i.e. information conservation is not a conservation law) or their measurement affects the photon via 'spooky action' to lessen its information content (i.e. the virtual photons are 'entagled' with the producing photons).


Well, conservation of information can be derived (both classically and quantum mechanically) from the Liouville theorem. I wasn't sure about conservation of information being violated here, but I guess that is what gave rise to my intuitive suspicion that there is a conservation violation at work. I guess anyone interested in a quick publication could check the author's math against the quantum version of the Liouville theorem, and see if there is a violation. I might have been capable of that back in grad school, but I don't think my math skills are up to the task right now.
JVK
1 / 5 (4) Apr 01, 2015
my intuitive suspicion that there is a conservation violation at work.


What you attribute to intuitive suspicion is clearly indicated in the title: "...could transmit information without transmitting energy."

That may be why others focus on the new theory. If they look at biologically-based cause and effect from any other perspective than untestable pseudoscientific nonsense, they would be forced to use the "common sense" that is lacking in the discussion here.

"What Ifs" would be replaced with experimental evidence of light-induced amino acid substitutions. The substitutions differentiate the cell types of all individuals of all species. That fact attests to the fact that "Life is physics and chemistry and communication" and that "Neural networks from beehives to brains solve problems through the exchange and the selective cancellation and modification of signals." https://www.youtu...ye4G1hiA

The energy-content of signals is informative.
Dethe
1 / 5 (3) Apr 01, 2015
In dense aether model no information can be transferred without transfer of energy, period. This energy can be just transferred in form of transverse or longitudinal waves of vacuum. The longitudinal way corresponds the spreading of sound at the surface of water - it's superluminal, elusive and more tricky to handle. It corresponds the spreading of evanescent waves in vacuum.
The afterglow also occurs in flat spacetime of dimensions other than 3+1
So it can be considered as an evidence of extradimensions. But the space-time of dimensions other than 3+1 cannot be "flat" - these two aspects exclude itself mutually.
Dethe
1 / 5 (3) Apr 01, 2015
I'd say, that the energy can be spread without transferring of deterministic information rather than that the information can be spread without exerting of energy. What do you think about it? Apparently, we do need to streamline and better define the concepts of energy and information.
JVK
1 / 5 (3) Apr 01, 2015
Apparently, we do need to streamline and better define the concepts of energy and information.


With definitions, you can invent many other theories and continue to avoid the required experimental evidence that links physics to the chemistry of protein folding and the conserved molecular biological of RNA-mediated life and biodiversity. Simply put, keep doing what you're doing and you can become evolutionary theorists.

"[W]hat Haldane, Fisher, Sewell Wright, Hardy, Weinberg et al. did was invent.... Evolution was defined as "changes in gene frequencies in natural populations." The accumulation of genetic mutations was touted to be enough to change one species to another.... Assumptions, made but not verified, were taught as fact." http://www.huffin...211.html
Nik_2213
5 / 5 (1) Apr 01, 2015
Seriously, seriously weird. Weirder than 'usual' run of quantum weirdness...

Even weirder that something so small may be able to measure the 'curvature' of the universe-- But how to distinguish that from mass-related gravitational dints in space-time ??

Perhaps our 'terrestrial' rules of physics only apply because we're deep within a planetary gravitational well, in a solar system, within a galaxy, within a cluster, within a super-cluster etc etc. While, out there, between the 'stuff', where space-time has a vanishingly small gradient, quantum physics must play by simpler rules...
{Shiver...}
antialias_physorg
5 / 5 (3) Apr 02, 2015
I wasn't sure about conservation of information being violated here, but I guess that is what gave rise to my intuitive suspicion that there is a conservation violation at work.

Shot the author a quick email regarding this. Maybe there's something in the math (which I honestly can't follow completely) we are missing.
bluehigh
2 / 5 (4) Apr 02, 2015
'Shot the author'

That's a bit harsh!

Though this kind of fantasy does bring real scientific effort into disrepute surely there's a less drastic response suitable,

Accata
1 / 5 (1) Apr 02, 2015
In classical Copenhagen model the photons cannot have any "afterglow" and the probability function of photon is overlapping with its wave function. In dense aether model, though, the photon is not a monolitic pilot wave. It has more dense "core" and the surrounding coat, which corresponds the pilot wave on deBroglie-Bohm pilot wave theory. The energy density of photon core differs from its pilot wave the more, the higher is the frequency of photon different from frequency of CMBR. Actually deBroglie later got the same insight with its double solution model. The important thing is, the pilot wave around photon can participate to information carried with it in the same way, like the quantum wave of photon core - but in indeterministic way, being density wave of vacuum. The difference in behavior of both parts of photon can be seen during double slit experiment - the real portion of photon creates the spots at the target, the imaginary one participates on wave-like distribution of them.
antialias_physorg
5 / 5 (2) Apr 02, 2015
Got banned again, Zeph? You don't take a hint, do you?
Accata
2.3 / 5 (3) Apr 02, 2015
The actually interesting hint is, that if the photons create the "afterglow" pilot wave around them like massive particles, they must be also massive, like these particles: If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck. This would also mean, that the photons cannot move with speed of light, or they couldn't create the pilot wave around them (the pilot wave is a bow wave unaffected with nature of particle which is forming it - so it's always luminal).
JVK
1 / 5 (3) Apr 02, 2015
Re: "The energy-content of signals is informative."
See also: http://www.jneuro...abstract

"...activation of the Go protein by GluK1 was validated in bioluminescence resonance energy transfer experiments, while the specificity of this association was confirmed in GluK1-deficient mice. These data reveal components of the KAR interactome, and they show that GluK1 and Go proteins are natural partners, accounting for the metabotropic effects of KARs."

This link from energy as information to metabolism and reproduction can be separated by theorists only if they want to continue touting pseudoscientific nonsense.

Apparently, that is what most the participants of this discussion want to do.

WHY?
Whydening Gyre
5 / 5 (1) Apr 02, 2015
Well, this one is WAY beyond my pay scale.
However, there are analogous examples out there.
I see this as sort of a photon generated "wind"...
Moving photons create a sort of minute relativistic disturbance in a "field" that we have not yet observed or quantized...
antialias_physorg
5 / 5 (5) Apr 02, 2015
Robert Harry Jonsson, Achim Kempf and Eduardo Martin-Marzinez (authors of the paper) were kind enough to reply. I'll first post my email, then the reply. This may take a couple of posts. Sorry for the wall of text):

My email:
Sorry to disturb you but we were having a bit of a discussion over on phys,org about your paper
"Information Transmission Without Energy Exchange"
(actually about the preprint version on arxiv). And I was wondering if you could answer a quick question.

In the paper it says:
" arbitrarily many spacelike separated receivers
could be arranged in the future lightcone of Alice, such
that all receive the same signalling contribution to Pe(t)"

..and we were wondering whether this violates a conservation of information? Or are we missing something, here?

Best Regards
....

(cont.)
antialias_physorg
4.8 / 5 (5) Apr 02, 2015
Dear ...,

That is indeed a very insightful question.

In our paper, we use quantum phenomena only to transmit classical information. Alice can broadcast her classical bit to many Bobs because classical information can be cloned without limitation.

Now we are not discussing this in our paper, but yes you are right, one can further ask what happens if Alice is trying to send a qubit to all of the Bobs. Quantum information cannot be cloned, of course. Therefore, Alice cannot send one qubit to arbitrarily many Bobs. Or more precisely, she may try to send a qubit to many Bobs but the many Bobs cannot all succeed in receiving it.
We have been studying the transmission of quantum information in our scenario for a while (in an extended collaboration) and this is one of the next things we want to publish. Intuitively, the Bobs' efforts to each receive Alice's qubit will be foiled for this reason:

(cont.)
antialias_physorg
5 / 5 (5) Apr 02, 2015
As Alice's signal reaches the quantum systems of the Bobs, Alice's signal will serve to correlate the Bobs' quantum systems. This then means that the Bobs can no longer completely independently try to scoop up Alice's quantum information. Any measurement of one Bob collapses to some extent the wavefunction of the other Bobs, preventing them from picking up the quantum part of Alice's signal independently.

Going forward, we are interested, in particular, in the more general question to what extent the overarching principle of "no cloning of quantum information" puts predictive constraints on the interplay between interaction and entanglement generation between quantum systems, such as here between the quantum field and the quantum systems of Alice and the Bobs.

Best regards,
Robert, Eduardo and Achim
DarkLordKelvin
3 / 5 (4) Apr 02, 2015
@AA .. Thanks for that. Their response is interesting, in that they seem to imply that there can only be a single "detection event" based on afterglow photons. I can't see any reason why that would be the case, at least not a priori. If the photon is arbitrarily generating these virtual photon pairs along its track, why would all but one "disappear" upon a detection event. Is part of the theory that ALL of these virtual photons are entangled into one giant quantum state with an arbitrary number of "occupants"? I don't remember seeing that in the paper, but some of the math kinda made my eyes glaze over a bit ...
DarkLordKelvin
2.3 / 5 (3) Apr 03, 2015
After thinking about this some more, I think that in addition to the issues with conservation of information, the claim that "information is transmitted without transmission of energy" by their model is also not correct. Assuming there is no violation of information conservation, then all they could say is that information and energy are transmitted and detected *asynchronously*. After all, they can't detect virtual photons from nothing, they have to detect those associated with the "afterglow" of a real photon, the production & transmission of which represents the "event" they are basing their signal on. Whatever happens to that real photon, all information transmission associated with it requires that it (and its associated) energy exist, and also that it be transmitted along a particular path.
DarkLordKelvin
2.3 / 5 (3) Apr 03, 2015
With that in mind, it's very hard to see how violation of information conservation could be avoided. Say I send a photon from Alice to Charlie, nothing fancy .. just a single photon generated by electronic decay inside an atom. Now, according to the paper, that photon has an associated "afterglow" of virt. photons that a 3rd observer, Bob, can detect "long after" the photon has been transmitted. Some questions spring to mind about the conditions under which this can be achieved:

- How are the trajectories of these virtual photons correlated with the real one? Can they have components orthogonal to the real photon trajectory?

- How close does Bob have to be to the "path" of the real photon?

- Does it actually have to pass through his detection apparatus (which was "open" when the real photon passed), as well as Charlie's?

- Or can Bob's measurement be displaced perpendicularly wrt the photon trajectory?

- If so, what are the limits on how far away it can be?
DarkLordKelvin
2.3 / 5 (3) Apr 03, 2015
Since the authors claim (or at least seem to) that the proposed scheme does not depend on whether or not the original "real" photon has been detected (i.e. destroyed), the properties of the "real" photon cannot depend on whether or not the putative 3rd observer (Bob) has made a measurement of one of the "afterglow" virtual photons. Therefore the contexts of the two measurements (of the real and virtual photons) must be considered as decoupled, or at least that possibility must be allowed for. As such, I cannot see how information would not be created any time Bob tries to make a measurement, under the conditions that Charlie has already detected the real photon associated with the afterglow.
DarkLordKelvin
2.3 / 5 (3) Apr 03, 2015
Another issue that I just noticed is with momentum conservation. Virtual particles are usually represented as being generated in particle/antiparticle pairs, because although conservation laws don't apply while the particles are virtual, if one of them is "reified", its partner must also become a real particle, because then conservation of charge, energy-mass, momentum, etc. all must be satisfied from the instant of reification onward.

Photons are their own antiparticles, so I guess afterglow virtual photons will also be created in matched pairs. However, the 3rd observer Bob is only going to detect one member of the pair, reifying it at the moment of detection. However momentum conservation will only be satisfied if there's counter-propagating real photon of equal energy is also reified at that instant.

Let's say that all works as above. What happens I set up Bob's apparatus so that the "partner photon" would pop into existence inside a solid object at the moment of detection?
antialias_physorg
5 / 5 (2) Apr 03, 2015
The way I read this reply is that they don't detect any properties of the photon emitted by Alice - just the correlation between whether there's one present or not.
The energy for making the virtual photons real comes from the on/off switching of the detectors. That is why any number of virtual photons at any number of detectors can be detected from the passage of one real photon.
(This is real information, not quantum information - so the no-cloning theorem does not apply).
The momentum/energy of the detection event (the virtual photon that is boosted to become real) all come from the detectors themselves.

It'll be interesting to see how their next paper deals with the same situation but with qbits instead of real bits.
DarkLordKelvin
2.3 / 5 (3) Apr 03, 2015
@AA ... not sure why you think there's no classical conservation of information. First of all, cons. of info can be derived from the Liouville theorem as applied to either classical or quantum systems. Second of all, quantum mechanics is the more general theory, and all predictions of classical mechanics must also be consistent with quantum mechanics (i.e. if one is applying classical laws, they must be sure that the system is sufficiently macroscopic that quantum effects are negligible at their level of precision).

Also, while the energy to reify the virtual photons may come from the detector, I don't really see how that can be true for momentum. That would essentially require that the detector be moving toward the photon BEFORE it is detected, so that the net momentum transfer is zero. Maybe that's theoretically possible with virtual particles, but I haven't encountered such as scenario before.
antialias_physorg
5 / 5 (2) Apr 03, 2015
Well, if you think about high energy photons in a detector than they can leave multiple traces of the fact that they are there. So the mere fact that only one photon is sent doesn't limit the detection to s single detector.
How the momenta are conserved is a bit tricky, but I thinnk the detector as to supply the appropriate energy.
Thinking about stuff like the casmimir force then virtual photons can exert a force.

Honestly, at this point I'm just guessing. I'd need to walk through the math on that one.
Dethe
1 / 5 (1) Apr 03, 2015
The first transmitting of information with photon "afterglow" "without transmitting of energy" did actually prof. Gurther Nimtz and he also proved, that this transmission was superluminal. Of course some portion of energy was still transferred during it - just in indeterministic way. These experiments are simple enough to reproduce in the kitchen. If you push the light into one filament from bundle of optical fibers, whole bundle will glow, because the photons will tunnel across space between fibers via evanescent waves. Apparently some energy is still lost in this way, just not in deterministically predictable way. If we could really transmit an information without transmitting of energy, it would lead into a Maxwell daemon and/or perpetuum mobile of 2nd kind.
DarkLordKelvin
3 / 5 (4) Apr 03, 2015
The first transmitting of information with photon "afterglow" "without transmitting of energy" did actually prof. Gurther Nimtz
*sigh* no .. not even close. I suppose you are referring to evanescent waves, which have nothing to do with the virtual photon "afterglow" mechanism claimed in the article above, and are not even quantum, since they are part of classical electromagnetic theory.
and he also proved, that this transmission was superluminal.
No, he just claimed it, and he was wrong (of course). Did you bother to read the wiki link you posted?
These experiments are simple enough to reproduce in the kitchen. If you push the light into one filament from bundle of optical fibers, whole bundle will glow, because the photons will tunnel across space between fibers via evanescent waves.
That behavior is not tunneling, and again, does not even require QM (although it is of course consistent with it).
DarkLordKelvin
3 / 5 (4) Apr 03, 2015
Well, if you think about high energy photons in a detector than they can leave multiple traces of the fact that they are there.
Really? Can you give an example?
So the mere fact that only one photon is sent doesn't limit the detection to s single detector.
I am pretty sure it limits it not only to a single detector, but also to a single detection event.
How the momenta are conserved is a bit tricky, but I thinnk the detector as to supply the appropriate energy.
Energy perhaps, but momentum and energy are separately conserved, so you can't just hand wave it away I don't think.
Thinking about stuff like the casmimir force then virtual photons can exert a force.
No, (almost) certainly not. The Casimir force is just the relativistically correct van der Waals force, as demonstrated by Jaffe.http://arxiv.org/.../0503158 There is no need to resort to virtual particles, which shouldn't be able to exert any kind of force if they aren't "reified".
antialias_physorg
5 / 5 (2) Apr 04, 2015
Really? Can you give an example?

Recently I came accross this:
https://www.mpq.m...13_11_15

Dethe
1 / 5 (1) Apr 04, 2015
I suppose you are referring to evanescent waves, which have nothing to do with the virtual photon "afterglow" mechanism claimed in the article above, and are not even quantum, since they are part of classical electromagnetic theory
Of course, many phenomena, which the scientists are revealing in recent time are already a part of another - mostly quite classical - theories. For example the gravitational waves are CMBR noise, the extradimensions manifest itself with various short distance forces and mini-black holes are common well known particles This is just the consequence of the fact, the physicists are looking for quantum gravity phenomena outside of common scope of quantum mechanics and general relativity - not between them. The finding of "afterglow" of photon belongs into same category.
Dethe
1 / 5 (1) Apr 04, 2015
Really? Can you give an example?
Yes, this is another good example of the localization of photon with its "afterglow". The gamma ray photons can be traced with spark chamber, for example or with scintillators in multiple events. During this the photon gradually loses its energy with Compton scattering mechanism. IMO this is the similar problem in the above study - the physicists should really check and compare the wavelengths of photons incoming into detector and after detection for to prove, no energy has been really transferred during transfer of information in this way. Just the fact, no photon has been lost during detection cannot serve as a complete evidence.
Dethe
1 / 5 (1) Apr 04, 2015
Thinking about stuff like the Casimir force then virtual photons can exert a force
The evanescent wave can be also interpreted as a collective action of virtual photons according to multipath integral formalism. After then the Maxwell force can be interpreted like the collective action of virtual photons.
Casimir force is just the relativistically correct van der Waals force
It doesn't explain, why normal van der Waals forces aren't relativistically corrected, whereas Cassimir force yes. Do you have some proposal for shutting down the special relativity at the case of common van der Waals forces? Not to say, that the van der Waals forces have often quite opposite sign, than the Cassimir force and they don't depend on the shape of objects with compare to the Cassimir force.
DarkLordKelvin
1 / 5 (2) Apr 06, 2015
Really? Can you give an example?

Recently I came accross this:
https://www.mpq.m...13_11_15



That is a very interesting example. I am still working through the paper. I don't think that it's really an example of non-destructive detection in more than a semantic sense though. The question I am working through right now is: could this "non-destructive detector" measure the *time* of detection to arbitrary precision (in an ideal case)? I am almost convinced the answer is "no". Another issue is how closely the impinging photon must match the energy state of the trapped atom in order for it to be detected.

Another, more basic question is, if the photon is "known" to have interacted with matter prior to normal, destructive detection. Can it really be considered "the same photon" that was emitted from the source, given the possibility of absorption/re-emission or inelastic scattering?
Dethe
not rated yet Apr 06, 2015
We can detect the paths of photons with multiple observations/detectors routinely. These photons aren't destructed during it at all, they even don't appear re-emited (do you know some atom, which would be able to re-emit the cosmic rays?) - but we still cannot say, that no energy is transmitted during process of observation - or we would invent the perpetuum mobile: we could bounce the photons with mirrors inside of small volume, thus letting them to produce sparks for ever. The memo is, you can read & consider the scientific reports, but you shouldn't forget to think about it.
DarkLordKelvin
1 / 5 (2) Apr 06, 2015
We can detect the paths of photons with spark chambers. These photons aren't destructed during it at all
Except that the cosmic rays detected in spark chambers aren't photons .. they're massive particles (e.g. often muons or protons).
we could bounce the photons with mirrors inside of small volume, thus letting them to produce sparks for ever.
Seriously? A single photon can produce exactly one photoionization event ... it is absorbed (i.e. destroyed), and the associated energetic excitation causes and electron to be ejected from the atom. A photon could create a single spark in a spark chamber, but not a trace.
The memo is, you can read & consider the scientific reports, but you shouldn't forget to think about it.
What about my posts makes you say I am not thinking about these "scientific reports"? I might suggest that you think more carefully about the spark chamber mechanism before suggesting photons can produce traces like massive particles.
Dethe
not rated yet Apr 06, 2015
Except that the cosmic rays detected in spark chambers aren't photons .. they're massive particles (e.g. often muons or protons).
About one fifth of them are true gamma ray photons. And the spark chamber can be used for their detection too.
A photon could create a single spark in a spark chamber, but not a trace.
This is just not true, if you stop with theorising and take a look at the video. It doesn't matter, how advanced your theory is, if doesn't matter, how smart you are, if the experiment says the opposite....
DarkLordKelvin
1 / 5 (2) Apr 06, 2015
Except that the cosmic rays detected in spark chambers aren't photons .. they're massive particles (e.g. often muons or protons).
About one fifth of them are true gamma ray photons.
Not at sea level, where the video was taken. The atmosphere is opaque to gamma photons.
And the spark chamber can be used for their detection too.
Yes, but the gammas themselves do not make TRACES in the spark chambers, which was what you claimed provided evidence that photons could be detected more than once. Sufficiently high-energy gammas can induce pair-production of counter-propagating, high-velocity MASSIVE particles (notice a theme yet?), which then produce the observed traces in a spark chamber. This happens via a SINGLE event which, like photoionization, results in the gamma photon being converted into massive particles (e.g. electron-positron pair). http://www.scienc...71905283
DarkLordKelvin
1 / 5 (2) Apr 06, 2015
Except that the cosmic rays detected in spark chambers aren't photons .. they're massive particles (e.g. often muons or protons)
About one fifth of them are true gamma ray photons
Not at sea level, where the video was taken. The atmosphere is not very transparent to short wavelength photons (shorter than vacuum UV).
And the spark chamber can be used for their detection too.
Yes, but the gammas themselves do not make TRACES in the spark chambers, which was what you claimed provided evidence that photons could be detected more than once. Sufficiently high-energy gammas can induce pair-production of counter-propagating, high-velocity MASSIVE particles (notice a theme yet?), which then produce the observed traces in a spark chamber. This happens via a SINGLE event which, like photoionization, results in the gamma photon being converted into massive particles (e.g. electron-positron pair). http://www.scienc...71905283
DarkLordKelvin
1 / 5 (2) Apr 06, 2015
This happens via a SINGLE event which, like photoionization, results in the gamma photon being converted into massive particles (e.g. electron-positron pair).


Clarification: my point here was that both pair-production and photoionization are single events that result in destruction of the impinging photon ... I was not trying to say that photoionization involves conversion of energy into massive particles.
Protoplasmix
not rated yet Apr 06, 2015
Interesting discussion. In the above setup, it isn't required that Alice emit a photon at all - she merely has to couple and decouple her detector from the field. I'm still working thru the paper (on 3rd pass, with fascinating diversions on weak/strong Huygens' principle and Liouville's theorem; halfway thru 1st pass I conceived a setup to measure curvature in 3d+1 before checking to see what kind of squid-like sensor a "UDW detector" was).

@AA - first let's shoot all the authors [an email]. Well done :)
Dethe
not rated yet Apr 06, 2015
but the gammas themselves do not make TRACES in the spark chambers, which was what you claimed provided evidence that photons could be detected more than once
Yes, they do. The Compton scattering is able to deflect the photon from its path multiple-times and ionize many atoms along its path without actual recreation of photon. Without it the Compton scattering couldn't work at all, as the photon would be always absorbed, not to say repeatedly. There are also another devices with rely on the repeated interaction of photons with matter, for example the Wolter mirrors used in focusing of X-rays in space-probes. Apparently, these mirrors couldn't work, if the photons wouldn't bounce repeatedly like the massive particles (which they actually are).
DarkLordKelvin
1 / 5 (2) Apr 06, 2015
but the gammas themselves do not make TRACES in the spark chambers, which was what you claimed provided evidence that photons could be detected more than once
Yes, they do. The Compton scattering is able to deflect the photon from its path multiple-times and ionize many atoms along its path without actual recreation of photon. Without it the Compton scattering couldn't work at all, as the photon would be always absorbed, not to say repeatedly
*sigh* Compton ionization is inelastic, involving re-emission of DIFFERENT photons, with different energies and trajectories. For photons, energy is a characteristic quantity .. i.e. "a photon" cannot change its energy (in a given reference frame). Similarly, for your reflection example, there is no way to tell if a given "reflection" event is really reflection, or elastic scattering, or absorption and re-emission. I think any time a photon interacts w/matter, it cannot be considered "the same photon" any longer.
Dethe
not rated yet Apr 06, 2015
Compton ionization is inelastic, involving re-emission of DIFFERENT photons
Compton ionization? How the lone free electron can re-emit something? Do you know what the Compton scattering is?
there is no way to tell if a given "reflection" event is really reflection, or elastic scattering, or absorption and re-emission
Of course it is. During absorption and re-emission the paths of incoming and outcoming photons are independent each other and essentially random (some recoil of target and redshifting of photons in one direction can be allowed). The Wolter mirrors couldn't work in this way, or way too many photons would be wasted. In addition, the gamma ray mirrors works for gamma ray photons of such energies, which would have nowhere to absorb inside of mirror atoms, re-emit the less, in the same direction even less. It must be the very same photons along the whole path along mirrors.
Dethe
not rated yet Apr 06, 2015
I think any time a photon interacts w/matter, it cannot be considered "the same photon" any longer
Isn't the whole above article about opposite conclusion? Try to describe the way, in which lone photon bounces along optical fiber for example. Do you think, that the photons can propagate across atoms unattended, or they're recreated from atom to atom? Do you think, such a photon gets recreated each time when it gets deflected with density gradient inside of fiber? Even if the change of direction gets infinitesimally small? Does some threshold for minimal radius of optical fiber exist in this way?
DarkLordKelvin
2.3 / 5 (3) Apr 07, 2015
Compton ionization is inelastic, involving re-emission of DIFFERENT photons

Compton ionization?
Yes .. you implied that the gamma photon was causing ionization of the *gas* in the spark chamber when it was scattered (else how would there be a spark), that process is properly called Compton ionization.
How the lone free electron can re-emit something?
Which "lone free electrons" are you talking about? There certainly aren't any of those inside a SPARK CHAMBER, or do you not understand how those work either? Except in fairly exotic set-ups (i.e. using electron beams inside vacuum chambers), Compton scattering occurs from electrons inside molecules or dense materials. The energy transferred to the electron is almost always more than enough to result in ionization of gas molecules, or creation of a "ballistic electron" in dense materials (c.f. scintillation counters).
Do you know what the Compton scattering is?
Yes, quite clearly.

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