A non-causal quantum eraser

Jan 09, 2013
This is a long time exposure photography viewing from Tenerife to La Palma. A green laser beam indicates the free-space link between the two laboratories. Credit: IQOQI Vienna

Whether a quantum object behaves like a wave or like a particle depends (according to the Copenhagen interpretation) on the choice of measurement apparatus used for observing the system, and therefore on the type of measurement performed.

Anton Zeilinger's team of physicists at the University of Vienna and the Austrian Academy of Sciences has recently taken this phenomenon further than ever. Whether a certain behaves like a particle or like a wave depends on the measurement performed on a second photon. In the new experiment, this second photon is so far separated from the first photon that no transfer of information whatsoever (the velocity of which can never exceed the speed of light) would be fast enough. Yet, the first photon behaves like a wave or like a particle, still depending on the measurement performed on the second. While the results of such experiments are fully consistent with , a clear explanation in terms of causality is impossible, as, according to Einstein's , any transfer of information is limited to the speed of light. The science article "Quantum erasure with causally disconnected choice" has appeared in the current issue of the renowned science journal (PNAS).

The basis: the delayed choice experiment

Gedanken experiments on the foundations of quantum mechanics have a long history. Such thought experiments were developed to play through and discuss the behavior of single particles, which contradict both and common sense, at least theoretically. One milestone was the 1978 delayed-choice experiment by Einstein's last collaborator John Wheeler. In this gedanken experiment, a single photon has two paths it could take in an interferometer. In its wave character, the photon will take both paths simultaneously. In its particle character, the photon needs to decide which of the two paths it will take. Wheeler proved, in accordance with quantum mechanics, that the decision whether the photon will behave as a wave or as a particle can be taken after even after it has already entered the interferometer.

The quantum eraser

The so-called quantum eraser, presented in 1982 by Marlan Scully and Kai Drühl, turned out to be another milestone. A quantum mechanically entangled pair of one photon and one atom is created. The atom can take two paths, emitting the photon in the process. By measuring the photon, it can now be determined which of the two paths the atom has taken. If we now measure the photon in such a way that it becomes fundamentally impossible to determine the atom's path, as a consequence, the information about which path the atom has taken is, so to speak, erased. The atom then exhibits phenomena which can only be explained by its taking both paths, as a wave.

Vienna quantum physicists turn off the causality factor in experiment

The two ideas, delayed choice and quantum eraser, have been realized in experiment both separately and in combination. In all past experiments, the possibility that the choice of measurement has a causal influence on the actual observation (by transmission of information slower than light) still remained, if only in principle.

In the two new experiments, one of which was performed in Vienna and one on the Canary Islands, this remaining possibility of a causal explanation was now ruled out. The researchers created a pair of photons, one of which was sent through two glass fibers while the other was sent to a different laboratory, 50 meters away in Vienna and 144 km distant on the Canary Islands. The second photon was entangled with the first in such a way that by measuring its polarization (horizontal or vertical), it was possible to determine which path the first one had taken. If the second photon's polarization was measured at 45 degrees, no deduction on the path of the first photon was possible, which then, as a wave, took both paths. The decision of which measurement to perform on the second photon was realized by means of a high-speed random number generator. In both experiments, also in the case of the 144 km long optical free space connection from La Palma to Tenerife across the Atlantic, the choice of polarization measurement at the Tenerife photon was completely separated causally from its twin in La Palma. And yet, the photon on La Palma behaved like a particle or like a wave, according to the Tenerife measurement.

"This rules out the possibility of any physical signal between the two photons. Introducing this non-causal choice is a substantial step beyond existing quantum eraser experiments, where such communication is still possible in principle", explains Xiao-Song Ma, the first author of the current article.

Consequently, the experiment can be seen as a complete realization of the quantum eraser concept, not via delayed choice (which theoretically might be influenced by past events) but using a causally separated choice (by rendering any causal influence impossible).

"Our work disproves the view that a quantum system might, at a certain point in time, appear definitely as a wave or definitely as a particle. This would require communication faster than light – which is dramatically at odds with Einstein's theory of relativity. And so, I think that this view needs to be abandoned completely. In a certain sense, quantum events are independent from space and time", says Anton Zeilinger.

Explore further: Interview with Gerhard Rempe about the fascination of and prospects for quantum information technology

Related Stories

Quantum physics mimics spooky action into the past

Apr 23, 2012

Physicists of the group of Prof. Anton Zeilinger at the Institute for Quantum Optics and Quantum Information (IQOQI), the University of Vienna, and the Vienna Center for Quantum Science and Technology (VCQ) ...

A new 'lens' for looking at quantum behavior

Dec 14, 2011

(PhysOrg.com) -- In a paper published in Physical Review Letters, researchers Daniel Terno (Macquarie University, Australia) and Radu Ionicioiu (Institute of Quantum Computing, Canada) provide a new perspe ...

Recommended for you

Better thermal-imaging lens from waste sulfur

8 hours ago

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Robotics goes micro-scale

19 hours ago

(Phys.org) —The development of light-driven 'micro-robots' that can autonomously investigate and manipulate the nano-scale environment in a microscope comes a step closer, thanks to new research from the ...

User comments : 54

Adjust slider to filter visible comments by rank

Display comments: newest first

AntiLite
2.8 / 5 (11) Jan 09, 2013
.
Noumenon
1.3 / 5 (29) Jan 09, 2013
In a certain sense, quantum events are independent from space and time", says Anton Zeilinger.


It is more sensible imo to say, 'quantum events can not be conformed within our a-priori intuitive conceptual framework of space and time'. Space and time are not physical things.
grondilu
not rated yet Jan 09, 2013
And so, I think that this view needs to be abandoned completely. In a certain sense, quantum events are independent from space and time


It has to. I mean, quantum mechanics is so deep that it had to be beyond space and time. I see that as a proof of Mach's principle. It also fits well with ncomms2076, holographic principle and stuff like that. It's also yet an other win for Everett.

Also, if at some point physicists want a theory that explains space-time itself, they would need a theory that works without those concepts. Quantum mechanics is a perfect candidate for that.
ValeriaT
1 / 5 (12) Jan 09, 2013
his would require communication faster than light – which is dramatically at odds with Einstein's theory of relativity
In dense aether model such an events are mediated with longitudinal density waves of vacuum - so called the scalar (Tesla) waves. These waves faster than the light in the similar way, like the underwater waves are faster than the surface ripples at the water surface.
kochevnik
2.3 / 5 (3) Jan 09, 2013
In dense aether model such an events are mediated with longitudinal density waves of vacuum - so called the scalar (Tesla) waves.
Do you think the above experiment would lend itself to a scalar wave generator?
Walter_Mrak
1 / 5 (3) Jan 09, 2013
Gravity is not understood yet! When will you guys get around to that one? There is no "location," "place," "time," or other "domain" that: existential, omnipresent, always impactful and pervious gravity has no impact upon! In other words, gravity is everywhere, aways and varies in "power," so must therefore be taken into account in considerations of anything and everything. I don't see this happening in physics today.
El_Nose
3 / 5 (4) Jan 09, 2013
@Noumenon

Actually Space is a physical thing. It is expanding in any given area due to the acceleration of Expansion, it is effected by gravity, and it effects EMR. We have not figured out what else is in space of without it as it were. And this experiment points to that lack of explanation. If we exclude FTL then something else is there. Be it a meduim or a mode.
GoodElf
1 / 5 (5) Jan 09, 2013
Interestingly this does mean "instantaneous communication" over any distance. N. Gisin has recently confirmed that "speed" of the information "sharing" between the Tenerife site related to the La Palma site exceeds 50,000 times the Speed of Light (lower bound)-- otherwise it is possibly infinite. This phenomenon (quantum entanglement) is "non-velocity causal" but also able to "share" information "globally".
See: Quantum correlations in Newtonian space and time: arbitrarily fast communication or nonlocality - N Gisin - arXiv:1210.7308v1 [quant-ph] 27 Oct 2012
Results verify that quantum entangled information is not local. Relativity "not broken" because the information is "not traveling" at all, it's "holographic". Science has it's cake and eats it too.
Noumenon
1.3 / 5 (27) Jan 09, 2013

Space is a physical thing. It is expanding in any given area due to the acceleration of Expansion, it is effected by gravity, and it effects EMR. We have not figured out what else is in space of without it as it were. And this experiment points to that lack of explanation. If we exclude FTL then something else is there. Be it a meduim or a mode.


The distance between galaxies is expanding, yes, but that is a relation between objects, ...basically a question. To say that space or time are physical entities one would have to discover them independently of their application in relating things.

They're intutiive concepts. If one takes mind as a component of 'phenomenal reality' as providing the conceptual structure in which we know it, then space and time are real in that sense. IOW, they are real only as an artifact of conceptualizing reality, and have no intrinsic existance, imo.

At the QM scale this artificial conforming of reality to our intuitions breaks down
vacuum-mechanics
1 / 5 (7) Jan 09, 2013
Whether a quantum object behaves like a wave or like a particle depends (according to the Copenhagen interpretation) on the choice of measurement apparatus used for observing the system, and therefore on the type of measurement performed.

Yes, but the problem is how the quantum object could behave like a wave or like a particle, what is its mechanism? Maybe this physical view could help to understand the mechanism.
http://www.vacuum...17〈=en
indio007
1.6 / 5 (7) Jan 10, 2013
God , people will say the damnedist things to save Einstein....
Seems to be the paper from the article.

A non-local quantum eraser
http://arxiv.org/...6578.pdf

"Our results demonstrate that the view point that the system photon behaves either definitely as a wave or definitely as a particle requires faster-than-light communication. Since this would be in strong tension with the special theory of relativity, we believe that such a view point should be given up entirely"

WTF!
Ojorf
3.4 / 5 (5) Jan 10, 2013
Interestingly this does mean "instantaneous communication" over any distance.


Oh grief, not again. This means no such thing, in fact the opposite.
johanfprins
1.6 / 5 (7) Jan 10, 2013
A single wave is a holistic entity that occupies a region in space. The wave IS in instantaneous contact with itself.

The size and shape of such a wave change when a measurement is made; since this changes the boundary conditions. If this requires a collapse in the boundaries of the wave which must happen at a speed faster than light, this will happen faster than light.

The "two-photons" in the Zeilinger experiment are NOT two separate waves but ONE holistic wave in instantaneous contact with itself. When you measure at one side of the wave, the other side knows this instantaneously. If the two waves were separate waves (or "particles" as the morons in charge of modern physics want to call them) they cannot communicate faster than light speed. Thus, this experiment DOES NOT invalidate Einstein!

Within the main body of a holistic wave, time does not exist. If it did exist an electron would not have been stable since its distributed-charge would have caused it to explode!
antialias_physorg
4.5 / 5 (8) Jan 10, 2013
Interestingly this does mean "instantaneous communication"
over any distance. Oh grief, not again. This means no such thing, in fact the opposite.

Agreed. People should really look up what communication entails before making such statements about "OMG, FTL info!".

I know the crucial point is subtle (a-priori infomation vs. no a-priori information), but having to go through the same shtick every time gets tedious.
Grallen
1 / 5 (2) Jan 10, 2013
To resolve entanglement in my mind. I had an idea that photons do not travel to their destination but instead tunnel through space/time. Their joint anchor point being technically in the past. So entangled photons are kind of like a joined wormhole that the center in in the past but both exits are in the present.

Meaning that when altered at one end they were still technically together, thus both were changed.

I thought about this because of the fact that photons are traveling at the speed of light might mean that for the photon, time doesn't pass in it's frame of reference until it's stopped. So... in it's frame of reference: the beginning and end point (in both space and time) are joined momentarily.

This also could explain the dual wave particle behavior.

I'm an amateur in physics really, and would have no idea how to create the math for this idea to even test if it's possibly true... so I know there is probably a million reasons this isn't right. So please, tear it apart
johanfprins
1.4 / 5 (9) Jan 10, 2013
@ natello. Spouting the same garbage under different aliases like also ValeriaT etc. does not hide the fact that you do not know any physics: You are just a bore!
johanfprins
1 / 5 (9) Jan 10, 2013
To resolve entanglement in my mind. I had an idea that photons do not travel to their destination but instead tunnel through space/time.
A photon is a coherent light-wave like any other coherent light wave: It moves with the speed c within ALL inertial reference frames. There is no space-time in the Special Theory of Relativity:

Minkowski was so stupid (No wonder Einstein distrusted him) that he did not know that the coordinates within a Cartesian system must be linearly independent: No matter how many dimensions are involved. Minkowski's space-time coordinates x,y,z, and ict, are NOT linearly independent. Thus, his construct is not mathematically possible: And I doubt that what is mathematically impossible can be physically possible.

Nonetheless, I like your approach: It shows that you have brains: The latter is completely absent within the bony heads of our modern-day theoretical physicists.

Grallen
1 / 5 (3) Jan 10, 2013
@johanfprins : Thanks for your corrections. I had no idea I was mixing incompatible theories, and would have continued on that path if not corrected. :)
Noumenon
1.2 / 5 (24) Jan 10, 2013
@johanfprins : Thanks for your corrections. I had no idea I was mixing incompatible theories, and would have continued on that path if not corrected. :)


Pay no heed to johanfprins, ...he does not know that all coordinates are orthogonal within an inertial reference frame, ... that (hyperbolic) orthogonally of the tangent to the world line, the time coordinate, is used to define simultaneity within a IRF. He rejects time dilation and photons.

Einstein in fact adopted Minkowski's geometrical approach, once he began incorporating gravity into special relativity.
Noumenon
1.4 / 5 (28) Jan 10, 2013
... photons do not travel to their destination but instead tunnel through space/time. Their joint anchor point being technically in the past. So entangled photons are kind of like a joined wormhole that the center in the past but both exits are in the present. Meaning that when altered at one end they were still technically together, thus both were changed. I thought about this because of the fact that photons are traveling at the speed of light might mean that for the photon, time doesn't pass in it's frame of reference until it's stopped. So... in it's frame of reference: the beginning and end point [..] are joined momentarily.


Interesting. Yes, photons do not experience time because of time dilation,... so effectively linking two spatial coordinates together (?).

Reminds me of an idea by Roger Penrose, in defining space-time by taking causality as fundamental, and constructing a geometry based on light rays, called twister space, or twister geometry.
johanfprins
1 / 5 (10) Jan 10, 2013
Pay no heed to johanfprins, ...he does not know that all coordinates are orthogonal within an inertial reference frame,
Noumenon=biggest IDIOT EVER on planet earth.

Let us test him: One has a four-dimensional orthogonal space with coordinates x, y, z, u: The magnitude of the distance s to a point x,y,z,u must then be s^2=x^2 y^2 z^2 u^2: And since these coordinates are linearly-independent, s can ONLY be zero WHEN x=y=z=u=0. In Minkowski-space u=ict, and therefore s can be zero even when x is not zero, y is not zero, z is not zero AND u is not zero. Thus Minkowski space is not an orthogonal four-dimensional space!

Einstein in fact adopted Minkowski's geometrical approach, once he began incorporating gravity into special relativity.
After for many years rejecting it. E only accepted it in desperation when he found that his theory of gravitation demands space-time curvature; which has NOTHING to do with Minkowski's impossible FLAT space-time: A blunder by E!
johanfprins
1 / 5 (7) Jan 10, 2013
Note the equation was not typed as s^2=x^2 y^2 z^2 u^2: BUT as

x^2 PLUS y^2 PLUS z^2 PLUS u^2

ValeriaT
1.7 / 5 (6) Jan 10, 2013
A photon is a coherent light-wave like any other coherent light wave:
Photon is photon, light-wave is Maxwell's wave. Maxwell's equations aren't quantized, therefore they cannot describe the photons (quanta of energy). The Maxwell's wave of dipole has no limit for its amplitude/dumping/scattering - whereas the photon is behaving quite differently: it's only absorbed completely or it isn't absorbed at all. The photon is as different from Maxwell's wave as every soliton (wave packet) is different from harmonic wave. The photon and light wave are simply two different denominations for two different physical concepts, which are related mutually, but they're still different. Those who cannot distinguish it cannot understand the particle-wave duality and the whole rest of corresponding physics, which is based on these concepts.
Noumenon
1.2 / 5 (23) Jan 10, 2013
The Minkowski metric uses a Lorentzian signature, η = diagonal {-1,1,1,1} and zero every where else, so that the inner product between any two basis vectors is 〈e∨μ, e∨ν〉 = η∨μν, ...

=δ ∨ij, (Kronecker delta)... implying orthonormality.

where ∨ = subscript.
Noumenon
1.7 / 5 (29) Jan 10, 2013
Note the equation was not typed as s^2=x^2 y^2 z^2 u^2: BUT as

x^2 PLUS y^2 PLUS z^2 PLUS u^2



I'll help you even though you're an insulting crank. A plus can be posted by using this HTML code without spaces,... & # 4 3 ;

s² = Δx²+Δy²+Δz²-c²Δt²
c0y0te
2.6 / 5 (5) Jan 10, 2013
".....random number generator...."

This is the main problem in my opinion. The so called random generator is part of our world, and therefore can hardly be truly random, even if it seems like one to us.

I suggest studying David Bohm.

http://www.vision...NDOMNESS

Also check Yves Couder's experiments as well, to perhaps get a grasp of what might be happening on a quantum level.

http://www.youtub...BaBdl0Aw
Tausch
1.7 / 5 (6) Jan 10, 2013
@Antilife
Erasure occured. (See the void as your comment - first post.)
If we don't measure you, then you are neither wave nor particle.
Path unknown. All the best. :)
RealScience
not rated yet Jan 10, 2013
Thanks, Noumenon, I've had pluses disappear and then wasted characters spelling things out.

So how did you get the deltas and the superscripts?
(I should take the time to learn HTML).
Noumenon
1.8 / 5 (30) Jan 10, 2013
Thanks, Noumenon, I've had pluses disappear and then wasted characters spelling things out.

So how did you get the deltas and the superscripts?
(I should take the time to learn HTML).


Here is some Greek symbols and other codes.
Tausch
1.8 / 5 (6) Jan 10, 2013
From a quantum information theory standpoint the word "quantum erasure" is not a part of the theory's vocabulary.
Quantum mechanics is a physical theory so I guess "quantum erasure" is appropriate here. Dunno.
What is meant exactly with the word "quantum erasure" here?
Tausch
1.7 / 5 (6) Jan 10, 2013
@lite
You departed from rating me one. I must have written something in English.
RealScience
5 / 5 (2) Jan 10, 2013
@Noumenon - Very useful, and I hope that it will improve the readability of my comments.

Thanks!
johanfprins
1 / 5 (8) Jan 11, 2013
Photon is photon, light-wave is Maxwell's wave. Maxwell's equations aren't quantized, therefore they cannot describe the photons (quanta of energy).


I should not waste my valuable time om a moron like you: But for the benefit of those lay people with brains who read your nonsense I must correct you. A photon is a Maxwell wave which has the lowest energy a source can emit or an absorber can absorb.
The Maxwell's wave of dipole has no limit for its amplitude/dumping/scattering -


Of course it has a limit: The limit is determined by the source!
whereas the photon is behaving quite differently:


No it is not behaving differently from any other Maxwell wave. It is emitted and absorbed like any Maxwell wave is: The only difference is that it is impossible to construct a source or detector that can emit or detect less energy than that of a photon-ELECTROMAGNETIC WAVE!!!
johanfprins
1 / 5 (9) Jan 11, 2013
The Minkowski metric uses a Lorentzian signature, η = diagonal {-1,1,1,1} ..


It still does not make Minkowski space-time orthogonal so that its coordinates are linearly independent!! In order to "move through" space-time following a world-line the coordinates of this space-time MUST BE ORTHOGONAL!

I think you should read an elementary book on linear algebra: I believe that at present one get textbooks that even a grade 8 pupil can understand: Not that this will guarantee that you will be able to understand it.

johanfprins
1 / 5 (8) Jan 11, 2013
Here is some http://www.htmlhe...ls.html.


Thank you noumenon: You know more than I expected. I am sorry about the insults: But what you believe is correct physics is not correct physics. But I do realize that it must be difficult to attempt thinking outside the mainstream. Galileo's peers had the same problem!
Anonym
1 / 5 (5) Jan 12, 2013
"The researchers created a pair of photons, one of which was sent through two glass fibers while the other was sent to a different laboratory, 50 meters away in Vienna and 144 km distant on the Canary Islands."

Only want to point out, there is an error in the above statement.
RealScience
5 / 5 (1) Jan 12, 2013
@Anonym - it is just not clearly written.
When the experiment was done in Vienna, one photon was sent through two glass fibers while the other was sent 50 meters away.
Later a similar experiment was done in the Canary Islands, and that time the second photon was sent a distance of 144 km.
Whydening Gyre
1 / 5 (9) Jan 12, 2013
What if - they were viewing the same photon, but from a different POV (ie - different physical locality, different time, etc)? This would explain the "instantaneous" communication.
Everything is a gradient flow of something else. The only thing that seems to benefit from this is awareness - which is spherical and therefore subject to the UN-real number Pi, and indicates an infinite number of radial scalar points. It does this via Phi - a cumulatively derived ratio (also an UN-real number with no absolute end).
Reality, existance, whatever you wish to call it is in actuality nothing more than an infinitely increasing sphere of awareness.
Most of you won't believe me, but it it's the simplest explanation of all the things we observe.
I get such a kick out of the conundrumness of it all..:-)
frajo
5 / 5 (8) Jan 13, 2013
subject to the UN-real number Pi
Pi is not an "unreal" number. It is a real number with the additional properties of being irrational and transcendental.
See http://en.wikiped.../wiki/Pi ,
http://en.wikiped...l_number ,
http://en.wikiped...l_number ,
and http://en.wikiped...l_number .
RealScience
5 / 5 (2) Jan 13, 2013
@Gyre - Since even coupled photons can be independently absorbed, they are not considered the same photon.

For the rest of your post I'll try to answer in your metaphysical language rather than in 'standard science speak'.

Instantaneous communication is not needed because becoming aware of the state of one photon determines which state your consciousness is in, and thus which state your consciousness will find the other photon in.
Everything detectable is a gradient, but gradients are not flows and not all gradients have flows.
Phi and Pi are lightly coupled - their interaction shows up in spirals in plants, for example, but most calculations involving one are not simplified by involving the other.
Consciousness is an increasing region of awareness, and thus your individual reality is as well. But this does not mean that all realities are the same sphere - there can be different realities and/or a timeless meta-reality.
johanfprins
1 / 5 (4) Jan 13, 2013
@ RealScience,

If you are serious about what you have just posted, then I am really baffled. What has consciousness to do with it?

Not that I am saying that consciousness should be ignored: After all we will not be communicating if we both did not experience self-awareness (or is it just a figment of my imagination?); but why invoke it when there is a causal solution to this "QM eraser" which is far simpler; and comes directly from Maxwell's equations?



ValeriaT
1 / 5 (5) Jan 13, 2013
Maxwell's equations are transverse wave model based, so they cannot predict anything, which is mediated with longitudinal waves. This is conceptual thing. For example, this is Maxwell's wave solution for dipole. You see: no photons, no quantization of energy, no superluminal information transfer, no density waves. Just pure harmonic wave propagating through space with speed of light. If some longitudinal wave or 2-spin component exists there, I've nothing against it, but such component must be introduced with another equation(s) or constrains - and after then the resulting solution will not be Maxwellian anymore.
RealScience
5 / 5 (3) Jan 13, 2013
@johanfprins - Whydening seemed to be struggling to communicate with users of this board, and getting a steady stream of ones as a result. Preferring more constructive feedback, I decided to try answering in his own language.

There are many possible mathematically correct interpretations of quantum mechanics and thus of entanglement and 'spooky action at a distance'. I picked the simplest one, which is also describable in terminology similar to that which Whydening has been using, and translated it into such terminology.

If you can translate a Maxwell's equations explanation of entanglement into the language that Whydening speaks, feel free to do so.
johanfprins
1 / 5 (5) Jan 13, 2013
Maxwell's equations are transverse wave model based, so they cannot predict anything, which is mediated with longitudinal waves.


Og! My God! When will we EVER get rid of this physics-moron. Light waves are NOT longitudinal and NEVER have been longitudinal, and do not HAVE to be longitudinal.

All coherent light-waves, from a laser-beam to a photon are transverse EM waves. PLEASE for God's sake, solve a few problems using Maxwell's equations (which you are obviously too incompetent to do) instead of spraying smelly nonsense around!! AWT! AWT! AWT! All Wonky Tonky!
johanfprins
1 / 5 (5) Jan 13, 2013
If you can translate a Maxwell's equations explanation of entanglement into the language that Whydening speaks, feel free to do so.
I have done it OVER and OVER and OVER on this forum, and have backed it up OVER and OVER and OVER with equations on this forum. It will NEVER penetrate such a bony-skull as that of ValeriaT.
cyberCMDR
not rated yet Jan 13, 2013
OK, so if a photon is slowed down in a non-vacuum medium, it must experience time during that phase of its travels. How does this change the universe, from the perspective of the photon?

"People assume that time is a strict progression of cause to effect, but *actually* from a non-linear, non-subjective viewpoint - it's more like a big ball of wibbly wobbly... time-y wimey... stuff." - The Doctor
cyberCMDR
not rated yet Jan 13, 2013
Deleted duplicate of comment. The first one didn't seem to take, and so was resubmitted.
johanfprins
1 / 5 (6) Jan 14, 2013
OK, so if a photon is slowed down in a non-vacuum medium, it must experience time during that phase of its travels. How does this change the universe, from the perspective of the photon?


In a vacuum a photon is moving with speed c and it has no rest-mass since it cannot be stationary within any inertial reference frame. It has no reference-frame to have a "perspective".

Within glass it slows down: This means that this "photon" is stationary within the reference frame moving with it. Only now the photon has a "perspective". While it moves through the material it has both kinetic-mass and rest-mass: the material causes the "drag" which gives the photon inertia.

However to talk about a "free photon" within a material is just as insane as talking about a "free valence-electron" within a material: Even if the material is a "perfect metal".

EM-energy can be trapped within a vacuum owing to space-time curvature: It is then a matter-wave: electron, proton etc.

No quarks, etc.!
eloheim
1 / 5 (1) Jan 15, 2013
In one way this is a completely non-surprising result. It fits fully in line with quantum mechanics. Obviously if this discovery had NOT been the case it would have been relatively earth shattering, compared to this.

On the other hand though, there are some VERY interesting issues that it brings up. I can't come up with any good example right now but my intuition tells me that the idea that there is no definite answer to whether a quanta is acting as a wave or particle at any certain time has some interesting philosophical implications. (I'm referring to the notorious "Interpretation of QM" issues here.)

The fact that for such a potentially interesting article, the comments section is so thoroughly filled with the same old crap (I think we all know what I'm talking about here) really bothers me. I would try to come up with something interesting to say about it to contribute to good conversation but I can tell already there's no real conversation to be had here.
eloheim
1 / 5 (1) Jan 15, 2013
@C0y0te
Looking at random number generators in this context is kind of interesting I think. I'm sorry I don't have time to look at the links you provided, but I see you're referencing Bohm. Google PBR theorem. I think if you use the random number generator thing as an out you end up advocating for a form of "Super-Determinism", where things have to be coordinated in a way that just doesn't seem plausible. (I.e. look at the "contextuality loophole" in these experiments.)

I'm not fully sure here, but I think if you take the idea that everything is "Super-Determined" and, in other words, things aren't really random, but they're determined by a "Hidden (variable) random number generator" you actually run into limits on the complexity of quantum computers allowed to exist, based on the number of total bits in the universe. How do you respond to that? (Maybe someone more expert in this field can help clarify.) Hopefully you'll know what I'm referencing here.
taka
1.3 / 5 (4) Jan 15, 2013
There is simple and natural explanation. When particles are entangled they ARE one object. This object is allocated outside our normal space, it only touches our space in one or MORE points or areas to be more precise. So, it is natural that information and energy inside that object is transfered instantly. It is the very real Wormhole. All quantum objects are Wormholes, that is the natural way they exist, what is weird is our space created by interactions of big number of such Wormhole objects.

To create usable Wormhole is actually simple. Just entangle two particles and you get it. As it is possible to influence and measure these particles without destroying entanglement (look "http://phys.org/n...m.html") the information can be sent faster then speed of light. Stargate is actually perfectly possible, not as in the movie but still. Can be also reason who SETI haven't hear anything, such communication cannot be listened in.
taka
1.8 / 5 (5) Jan 15, 2013

Reminds me of an idea by Roger Penrose, in defining space-time by taking causality as fundamental, and constructing a geometry based on light rays, called twister space, or twister geometry.


That is what I believe is happening. Particles itself are outside of our space, interactions between them create it.

Particles are not particles and not waves, these are two theories trying to describe particle properties. Both are correct, but not precise (no theory is precise). Both capture only part of properties.
Whydening Gyre
1 / 5 (5) Jan 15, 2013
@Gyre - Since even coupled photons can be independently absorbed, they are not considered the same photon.

For the rest of your post I'll try to answer in your metaphysical language rather than in 'standard science speak'.

Instantaneous communication is not needed because becoming aware of the state of one photon determines which state your consciousness is in, and thus which state your consciousness will find the other photon in.
Everything detectable is a gradient, but gradients are not flows and not all gradients have flows.
Phi and Pi are lightly coupled - their interaction shows up in spirals in plants, for example, but most calculations involving one are not simplified by involving the other.
Consciousness is an increasing region of awareness, and thus your individual reality is as well. But this does not mean that all realities are the same sphere - there can be different realities and/or a timeless meta-reality.

My only answer to that is E=M(CC):-) or-change happens
Whydening Gyre
1 / 5 (5) Jan 15, 2013
Everything changes. But only with a variable being added to it.
Falsify this mathematic statement - A. You cannot, since it has nothing else to relate to. But, by calling it a mathematical statement and by using a letter to indicate it is a variable term under the previously stated definition, I make it so.
Therefore, given that condition, A=(E=mc2)). In layman's terms it means - everything attempts to average out, but never will.
There. A TOE.
Yeah, but... it is the left toe or the right?

More news stories

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Robotics goes micro-scale

(Phys.org) —The development of light-driven 'micro-robots' that can autonomously investigate and manipulate the nano-scale environment in a microscope comes a step closer, thanks to new research from the ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Chronic inflammation linked to 'high-grade' prostate cancer

Men who show signs of chronic inflammation in non-cancerous prostate tissue may have nearly twice the risk of actually having prostate cancer than those with no inflammation, according to results of a new study led by researchers ...

Cosmologists weigh cosmic filaments and voids

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational ...