Reflecting light off satellite backs up Wheeler's quantum theory thought experiment

October 26, 2017 by Bob Yirka report
Credit: CC0 Public Domain

A team of researchers with Università degli Studi di Padova and the Matera Laser Ranging Observatory in Italy has conducted experiments that add credence to John Wheeler's quantum theory thought experiment. In their paper published on the open access site Science Advances, the group describes their experiment and what they believe it showed.

The nature of has proven to be one of the more difficult problems facing physicists. Nearly a century ago, experiments showed that light behaved like both a particle and a wave, but subsequent experiments seemed to show that light behaved differently depending on how it was tested, and weirdly, seemed to know how the researchers were testing it, changing its behavior as a result.

Back in the late 1970s, physicist Johan Wheeler tossed around a thought experiment in which he asked what would happen if tests allowed researchers to change parameters after a photon was fired, but before it had reached a sensor for testing—would it somehow alter its behavior mid-course? He also considered the possibilities as light from a distant quasar made its way through space, being lensed by gravity. Was it possible that the light could somehow choose to behave as a wave or a particle depending on what scientists here on Earth did in trying to measure it? In this new effort, the team in Italy set out to demonstrate the ideas that Wheeler had proposed—but instead of measuring light from a quasar, they measured light bounced from a satellite back to Earth.

The experiment consisted of shooting a at a splitter, which aimed the beam at a satellite traveling in low Earth orbit, which reflected it back to Earth. But as the light traveled back to Earth, the researchers had time to make a choice whether or not to activate a second as the light was en route. Thus, they could test whether the light was able to sense what they were doing and respond accordingly. The team reports that the light behaved just as Wheeler had predicted—demonstrating either particle-like or wave-like behavior, depending on the behavior of those studying it.

Explore further: The 'great smoky dragon' of quantum physics

More information: Francesco Vedovato et al. Extending Wheeler's delayed-choice experiment to space, Science Advances (2017). DOI: 10.1126/sciadv.1701180

Abstract
Gedankenexperiments have consistently played a major role in the development of quantum theory. A paradigmatic example is Wheeler's delayed-choice experiment, a wave-particle duality test that cannot be fully understood using only classical concepts. We implement Wheeler's idea along a satellite-ground interferometer that extends for thousands of kilometers in space. We exploit temporal and polarization degrees of freedom of photons reflected by a fast-moving satellite equipped with retroreflecting mirrors. We observe the complementary wave- or particle-like behaviors at the ground station by choosing the measurement apparatus while the photons are propagating from the satellite to the ground. Our results confirm quantum mechanical predictions, demonstrating the need of the dual wave-particle interpretation at this unprecedented scale. Our work paves the way for novel applications of quantum mechanics in space links involving multiple photon degrees of freedom.

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Jeffhans1
1 / 5 (5) Oct 26, 2017
This would allow us to negate transmission time bringing satellite internet latency down to zero. We would be able to do the same with communication within the solar system as long as the carrier signal is maintained.
Hyperfuzzy
1 / 5 (5) Oct 26, 2017
Every experiment with actuality and any object within the path of wave, appears at a point within this interface of either your reflector and or measuring device. For no thing can exist without charge. Charge is the field.and each charge is unique.
billpress11
3 / 5 (3) Oct 26, 2017
Could it be we are just looking at light wrong? What if we looked at it as waves of particles, more like the way Newton described light? That way it would always appear to us at the way we tested it for because it is both. This is how I think they should conduct this test, both for waves and photon side by side at the same instant.
Hyperfuzzy
1 / 5 (6) Oct 26, 2017
Try it without imagination and replace imagination with logic. Charge exists and is continuous. Therefore, its presence is felt everywhere. That is, it exist from it's center to infinity. "There is no beginning or end to this story." Without fiction. Light is the wrinkle in this "sea" of fields, each unique. Sort them any way you wish but the wavelengths are from 0 to infinity, also. And may exist exist as we perceive them from two points, it is always before perception, but do the math in a vector space. What you see may be from multiple directions. The motion of charge creates the wrinkle and affects every charge in its path.
Hyperfuzzy
1 / 5 (6) Oct 26, 2017
The "speed" of light is only relative to the measured not the vector field! So don't forget the "Host".
KBK
1 / 5 (3) Oct 26, 2017
See McTaggart's book, 'the field', available as a pdf. (web search for the pdf)

This is where the full explanations of these effects and issues, are going to take you.

Essentially, to a place where the idea of objectivity finally bites the dust.

The evidence in the gedankenexperiment is showing you that objectivity is simply ---not possible. Among other things.

The book will put very strong finalized coffin nails in that, for you.

It has a 40 page bibliography to allow you to do your own proofing of the data, if you find it a bit tough to deal with.
Hyperfuzzy
1 / 5 (6) Oct 26, 2017
See McTaggart's book, 'the field', available as a pdf. (web search for the pdf)

This is where the full explanations of these effects and issues, are going to take you.

Essentially, to a place where the idea of objectivity finally bites the dust.

The evidence in the gedankenexperiment is showing you that objectivity is simply ---not possible. Among other things.

The book will put very strong finalized coffin nails in that, for you.

It has a 40 page bibliography to allow you to do your own proofing of the data, if you find it a bit tough to deal with.

Yes, it is great fiction. But "The Force Luke!"
Hyperfuzzy
1 / 5 (5) Oct 26, 2017
So we are having trouble understanding propagation and the source by forgetting the host, lol!

"It's a miracle!"
Homebrook
1 / 5 (2) Oct 26, 2017
It is no surprise that light, which is both a particle and a wave at the same time looks like a wave when you measure it with an instrument measuring waves, or like a particle, when measured with an instrument measuring particles. The surprise is that anybody give the least credence to the nonsensical Copenhagen Interpretation of Quantum Mechanics. In Bohmian Mechanics all this makes perfect sense.
rogerdallas
4 / 5 (4) Oct 26, 2017
Would it not be simpler to say that in the case of light you find what you are looking for at the point of measurement? If you set up for wave properties you find wave properties and if you set up for particle properties you will find that. But if anything is "happening" it is happening at the point and at the moment of measurement. I'm not aware of any experimental arrangement that would show wave and particle properties simultaneously.
Hyperfuzzy
1 / 5 (5) Oct 26, 2017
Would it not be simpler to say that in the case of light you find what you are looking for at the point of measurement? If you set up for wave properties you find wave properties and if you set up for particle properties you will find that. But if anything is "happening" it is happening at the point and at the moment of measurement. I'm not aware of any experimental arrangement that would show wave and particle properties simultaneously.

You don't get it, the wave has the velocity vector of its source. The reflected wave depends upon the dynamics of your reflector. re. EE, Transmitted, reflective, dynamics, optical is just the optics? But let's allow 100% transmission without delay, i.e. hypothetical. So exactly how did the reflected surface perform. You must have this based upon something definable, it's the response of the surface material. There has to be a charge that responded to the field, and the "Host".
Hyperfuzzy
1 / 5 (4) Oct 26, 2017
You can't suggest you are correct with certainty, Unless you understand that field you detect has only one source. So any discussion on particle's has never been demonstrated. And logic, does not require a particle to define any tech. However, if you get the dough, to ahead, play around with dreams, cat's in boxes, thought experiment without logic. Simple, the world does not fit your imagination, it is completely filled with these field centers and their field. And that's as far as one can Logically define Physics. QM schools are fine, cause we are interested in wavelets; however, the basis i8n particle physics is an error.
antialias_physorg
5 / 5 (7) Oct 26, 2017
This would allow us to negate transmission time bringing satellite internet latency down to zero.

Erm...whut? I think you're missing some very fundamental basics, here.
shavera
5 / 5 (8) Oct 26, 2017
What if we looked at it as waves of particles, ... both for waves and photon side by side at the same instant

So, the thing is, we don't know of any way to do that. Pretty much any experiment we can think of forces the result to be one or the other. In the simpler double-slit experiment, anything we put to measure a particle going through one slit or another always forces the entire behaviour to be like particles and nothing like waves. Or if we ignore which slit so we don't know it's "particular path", the result behaves in a wavelike manner. No matter how we vary the experiment to try to allow for both at the same time, we get one behaviour or another.

re: Copenhagen, This experiment doesn't contradict the Copenhagen interpretation, even if it maybe stretches how one thinks about it. I'm not a fan of CI myself, but let's not be hasty to kill it off just yet.
shavera
5 / 5 (8) Oct 26, 2017
But if anything is "happening" it is happening at the point and at the moment of measurement.


That is the essence of the Copenhagen interpretation. Light travels through the system, neither along a specific path, nor like a diffuse wave, but when it hits the detector, the way the detector is set up forces the light to resolve into one state or the other. It's the classic "belief" about what happens in quantum mechanics. But there are many alternatives to this formulation, none of which can be experimentally distinguished at this time, and possibly never.
Hyperfuzzy
1 / 5 (5) Oct 26, 2017
...
we get one behaviour or another.

re: Copenhagen, This experiment doesn't contradict the Copenhagen interpretation, even if it maybe stretches how one thinks about it. I'm not a fan of CI myself, but let's not be hasty to kill it off just yet.

Sorry dude, it can be calibrated to actuality and simulated on your computer before experimentation. If you cannot do that you have no understanding of what you are doing. I mean this respectfully. I'm open to logical arguments for your definition and expression of charge and its field, define every event you've measured and causality. And try my axiomatic theory of what exist. If you want I'll go through your instrumentation, define your output signal, fuzzify it to atmospheric conditions, the point of contact upon your reflector and a quantum model of the reflectance or an actual motion required by each charge at each interface, the expected reception vector, the received signal, and as you wish ignore the
Hyperfuzzy
1 / 5 (5) Oct 26, 2017
frequency behaviour(Not); defined polarization, and a reasonable Poynting Vector upon each transition path. Note that signal's relative speed between the transmitter and your receiver is not a constant. You're ignoring the vector supplied by the reflector, if you wish, call it a push or pull, but what is happening, the signal leaving the reflector has the speed of the reflector. I thought we proved that with Michelson and Morley looking at themselves in a mirror and bot a satellite or a signal from a defined object.
Hyperfuzzy
1 / 5 (6) Oct 26, 2017
Whose brave enough to disregard the standard model as nonsense as well as GR or know what is happening in QM. After such idiotic predictions. Yes we have the smarts but not the guts. Why is that?
Hyperfuzzy
1 / 5 (5) Oct 26, 2017
Note the Poynting Vector describes the field measured but lacks a definite wavelet directional velocity Vector, that is the entire Field moves a a relative. Well not the Field, the wrinkle moving as a sphere relative to a charge. With the assumption of the speed relative to charge's center defined.
rrwillsj
3 / 5 (3) Oct 26, 2017
Well I'm satisfied that I can be right and wrong and really, really confused... All simultaneously!
RobertKarlStonjek
3.7 / 5 (3) Oct 26, 2017
I don't see how this contradicts a simple model that says that photons are particle like at the point of emission and absorption and wavelike between those points...I get the feeling that QM physicists have over-thought a phenomena than is intrinsically simple in nature...
Whydening Gyre
1 / 5 (1) Oct 27, 2017
In thinking about it....
do sensors induce or reduce turbulence (depending on which you are looking for..)?
Ddoodle
1 / 5 (1) Oct 27, 2017
there is no sensor it only becomes a sensore because you are looking at it that way.
TheGhostofOtto1923
4.3 / 5 (3) Oct 27, 2017
Well I'm satisfied that I can be right and wrong and really, really confused... All simultaneously!
But you wouldnt know which exactly until you compared it with evidence and resolved the conflict; an appropriate allegory to wave function collapse.
Hyperfuzzy
1 / 5 (2) Oct 27, 2017
Why are we wasting money and time trying to physically prove something; when you have no Formal Logical Proof, interpretation is not proof. So I see there is nothing here. Bye.
sirdumpalot
3 / 5 (1) Oct 27, 2017
So wait, I don't get it - the delayed choice changes previously measured values of the photon or just some future measurement?
Da Schneib
5 / 5 (2) Oct 27, 2017
Hmmm, not sure what value this adds to the Delayed Choice Quantum Eraser.

One of the fine points about the DCQE is that you can't detect the interference in the signal path until you've received both the signal and idler photons. In the signal path, without coincidence information from the idler path, you can't tell which signal photons had their path determined by an idler photon measurement and thus didn't show interference without the coincidence data provided by the idlers. The signal always looks like non-interference until you remove the signal photons for which you got an idler result that determined their path through the diffraction slits. Once those are removed interference fringes can be retroactively determined to have been present. But you can't see them until you have the idler photons.

Transmission to a satellite is too lossy to permit one leg (signal or idler) to traverse that path.
Da Schneib
5 / 5 (2) Oct 27, 2017
Jack Cramer, the man who developed the Transactional Interpretation of Quantum Mechanics (TIQM) based on Wheeler-Feynman Absorber Theory (yes, the same Wheeler and yes, THAT Feynman), proposed adding a path down the LIGO tunnels in Hanford to do pretty much the same thing these guys just did with a satellite ten or fifteen years ago, and switching that path among the signal and idler paths in the DCQE, but they never let him do it.

Another fine point is, you can't tell whether a particular signal photon has shown or not shown interference; interference fringes are ensemble behavior and a single photon is not a large enough sample to show it.

If you could, then you could show actual direct causality inversion. A lot of people look at the DCQE and think one could until you point these things out.
torbjorn_b_g_larsson
5 / 5 (1) Oct 29, 2017
The problem with delayed choice experiments is that they only show one way how current quantum process description differ from classical physics. As bill and roger intuits we do not see observables existence before the quantum system interacts with, say, the measurement device, but in classical physics it works perfectly fine to sloppily assume their previous existence. In practice, outside these types of experiments, the increased knowledge of how physics work has little consequence.

That does not make physics 'non-objective' however, obviously these/our observations are robust and quantifiable. Nor that we somehow can 'negate transmission time' since we need to conventionally signal observations between pairs of observers to make the correlative comparisons involved.

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