Scientists unveil the first-ever image of quantum entanglement

The Copenhagen group. Look at the names below. These were the greats.



A. Piccard, E. Henriot, P. Ehrenfest, E. Herzen, Th. de Donder, E. Schrödinger, J.E. Verschaffelt, W. Pauli, W. Heisenberg, R.H. Fowler, L. Brillouin;

P. Debye, M. Knudsen, W.L. Bragg, H.A. Kramers, P.A.M. Dirac, A.H. Compton, L. de Broglie, M. Born, N. Bohr;
I. Langmuir, M. Planck, M. Curie, H.A. Lorentz, A. Einstein, P. Langevin, Ch.-E. Guye, C.T.R. Wilson, O.W. Richardson

 

Agreed.

I'm just not so sure that counts as information being communicated. You can't send a message.

I thnik it counts as LESS than sending useless information - I don't think it counts as sending information.

 

Solvey Conference of 1927? (if memory serves). An iconic photo.

 

The state of the distant particle, when measured by a distant device, conveys information about the state of it's partner here, instantaneously. This is the spooky action at a distance Einstein referenced. Both particles exist in a superposition of Eingenstates, ie, they are both, both spin up and spin down [both are both dead and alive], until one is measured. Then the other one magically assumes the opposite state. It can be logically proven that neither particle could have had a hidden state [no hidden variables]. So somehow, the state of the measured particle must be instantly communicated to the other particle. ie spooky.

 

So... How do we find these particles ..... and how do we use them for long distance communication? Or... how do we catch these things?

 

As an example of entanglement: a subatomic particle decays into an entangled pair of other particles. The decay events obey the various conservation laws, and as a result, the measurement outcomes of one daughter particle must be highly correlated with the measurement outcomes of the other daughter particle (so that the total momenta, angular momenta, energy, and so forth remains roughly the same before and after this process). For instance, a spin-zero particle could decay into a pair of spin-½ particles. Since the total spin before and after this decay must be zero (conservation of angular momentum), whenever the first particle is measured to be spin up on some axis, the other, when measured on the same axis, is always found to be spin down. (This is called the spin anti-correlated case; and if the prior probabilities for measuring each spin are equal, the pair is said to be in the singlet state.)
https://en.wikipedia.org/wiki/Quantum_entanglement#Meaning_of_entanglement

Generally, entangled pairs are produced through some kind of subatomic decay process.

 

A funny thing about quantum effects. I don't know if you are familiar with the effect called diffraction. Diffraction is a phenomenon observed in waves, not particles. Particles act like bullets. But waves can go around corners and be in more than one place at once. For example, in the case of circular waves below, you can see regions where the waves exist, and other regions where they don't. This is an effect of waves interacting with each other.



According to Louis de Broglie, everything has a wavelength that can be calculated based on its momentum, and Plancks constant.


This led me to ask the following. If I can calculate a wavelength based on momentum, then for a momentum that is very very small, the wavelength becomes significant at large scale. So, if I walk through a doorway slowly enough, making my wavelength about the size of the door, like with the circular waves above, I should diffract like those waves do. So we should be able to observe quantum effects at scale, and I could exist at more than one place as a wave.

But, it turns out that we couldn't walk slowly enough. Each molecule and atom in my body has a certain amount of motion due to heat. And the momentum of those particles is already too high for me to diffract as a walk through door very very slowly.

So I considered the case that I walk through a door while at a temperature near absolute zero. Just for grins, let's say I could. THEN would I diffract when I was through a door very very slowly. Well... I should. So how slowly do I have to move? It turns out, I would have to walk so slowly, that it would take much much longer to pass through the doorway, than the time the universe has existed.

 

Sure. I think the issue there is whether that counts as communicating information.

Let's say we had an arbitrary number of such particles, each with it's "other" being aboard the international space station. Now, we find out that Trump won't be impeached. How would we communicate that using "spooky action at a distance"? What would the algorithm be?

 

You are talking about useful information. I addressed that point to begin with. But it requires information communicated inside the system to maintain conservation of spin. Somehow the two particles are in communication with each other. In fact it is often said that they act as one particle.

It calls into question the very concepts of time and distance.

 

You have your thinking cap on. (good for you!). I'm not familiar with diffraction.

 

That was several decades ago, when I was early in my college career.

The point is, this is an example where we should be able to observe quantum mechanical strangeness at large scale. But it would take billions of trillions of years to see it.

It is often funny how the universe seems to conspire to prevent us from making certain observations.

 

We still need to be careful about what is information and how it may be transmitted.

I don't believe QM destroys information theory.

 

I have no idea what you are talking about. I never said anything about destroying information theory.

 

Well, I didn't mean that you intentionally attacked that theory.

However, it would be a stupendous break in information theory to suggest that information can be transmitted at faster than light speed.

If the entanglement scenario involves instantaneous transmission of information, then I'm pretty sure there are major problems with our model of physics.

I'm not a physicist, of course!

 

It seems possible to me quantum entanglement is functioning transdimensionally. The two particles linked through another 'plane' where they havn't been separated (or perhaps are the same particle) could account for this behavior. In 'sci-fi' vernacular, I think the particles would be called 'multi-phasic' if they are 'phased' into two or more planes or 'realms'.

I've heard that certain processes like hydrolosis energy generation that have claimedly been shown to 'create' energy are actually 'borrowing' energy from other parallel realms. Perhaps quantum entanglement operates similarly.

 

What saves it from violating Relativity is that the information is not useful for ordinary communication. And this is nothing new. This is one reason Einstein didn't accept Quantum Mechanics. But it has stood the test of time for almost a century now.

The Einstein–Podolsky–Rosen paradox (EPR paradox) is a thought experiment proposed by physicists Albert Einstein, Boris Podolsky and Nathan Rosen (EPR) that they interpreted as indicating that the explanation of physical reality provided by quantum mechanics was incomplete...
https://en.wikipedia.org/wiki/EPR_paradox

 

If it were shown that a process borrowed energy from a parallel universe, it would be the biggest story in physics.

David Bohm suggested something similar to the idea of functioning transdimensionally. But it gets heavy,

The explicate order and quantum entanglement[edit]
Central to Bohm's schema are correlations between observables of entities which seem separated by great distances in the explicate order (such as a particular electron here on earth and an alpha particle in one of the stars in the Abell 1835 galaxy, the farthest galaxy from Earth known to humans), manifestations of the implicate order. Within quantum theory there is entanglement of such objects.

This view of order necessarily departs from any notion which entails signalling, and therefore causality. The correlation of observables does not imply a causal influence, and in Bohm's schema the latter represents 'relatively' independent events in space-time; and therefore explicate order.
https://en.wikipedia.org/wiki/Wholeness_and_the_Implicate_Order

Generally:
Implicate order and explicate order are ontological concepts for quantum theory coined by theoretical physicist David Bohm during the early 1980s. They are used to describe two different frameworks for understanding the same phenomenon or aspect of reality. In particular, the concepts were developed in order to explain the bizarre behavior of subatomic particles which quantum physics struggles to explain.

In Bohm's Wholeness and the Implicate Order, he used these notions to describe how the appearance of such phenomena might appear differently, or might be characterized by, varying principal factors, depending on contexts such as scales.[1] The implicate (also referred to as the "enfolded") order is seen as a deeper and more fundamental order of reality. In contrast, the explicate or "unfolded" order include the abstractions that humans normally perceive. As he wrote,

In the enfolded [or implicate] order, space and time are no longer the dominant factors determining the relationships of dependence or independence of different elements. Rather, an entirely different sort of basic connection of elements is possible, from which our ordinary notions of space and time, along with those of separately existent material particles, are abstracted as forms derived from the deeper order. These ordinary notions in fact appear in what is called the "explicate" or "unfolded" order, which is a special and distinguished form contained within the general totality of all the implicate orders (Bohm 1980, p. xv).

 

Spin is generally the conserved value shared between two entangled particles. In the example mentioned above, a particle having zero angular momentum decays into two daughter particles have opposite spin - thus conserving the zero angular momentum of the original particle. Spin in itself is a complicated concept in the quantum world. It is quantized [can only have certain values] and doesn't represent angular momentum as we think of it in the macro world. It was first demonstrated to be quantized in the quantum world in the Stern-Gerlach experiment.
https://en.wikipedia.org/wiki/Stern–Gerlach_experiment

Consider the spin angular momentum of light. It is really a measure of the rotation of the electric field, or the polarization.
https://en.wikipedia.org/wiki/Spin_angular_momentum_of_light

Spin alone is a complicated concept. In fact, most concepts in quantum mechanics become purely mathematical concepts that we can't model in our brains. We run into other wild things such as temperatures below absolute zero, and electrons that take on a negative mass while traveling down a wire.

I am often reminded of the words of Richard Feynman, in the introduction of his book, Quantum Electrodynamics [QED] - a subject he invented.

― Richard P. Feynman, QED: The Strange Theory of Light and Matter

 

Are you having fun, or are you trying to make a point?

I'm not opposed to either!

 

Just passing along related thoughts on the subject. Problems like this are why I went into physics.

 

Spin can be measured on any axis, X, Y, or Z. But measurement on one axis destroys all information about spin in either of the other two axes. And at the moment one particle is measured for spin on the X axis, it's entangled partner must also have spin on the X axis in order to satisfy conservation of spin [in our example].

So this makes me wonder how this works if we make simultaneous measurement on both particles, but in different axes. Measure one for spin in X, and measure the other for spin in Y. Interestingly, you immediately have to ask, what is simultaneous? Relativity tells us that simultaneity is relative. This might actually make the problem moot. The universe may conspire to prevent us from doing this through relativity. I need to think about that.

But, assuming that isn't the case, If measurement of spin in the X axis on particle 1 destroys all information about spin in Y and Z for particle 1, it seems that it must also destroys all information about Y and Z in particle 2. And if measurement of spin in the Y axis on particle 2 destroys all information about spin in X and Z for particle 2, and also destroys all information about X and Z in particle 1, then it seems that we couldn't make either measurement. We wouldn't measure any spin? But that is just shooting from the hip. I don't remember seeing a formal treatment of this question.

Perhaps by making two separate measurements, we avoid violations of Heisenberg's Uncertainty Principle, which is what is really at work here. This is what limits our knowledge of spin to one axis. We can only have knowledge of one axis per measurement... And by measuring for spin in Y on particle 2, we have knowledge of spin in Y on particle 1. This allows us to have knowledge of spin in X and Y on particle 1, but it still takes two separate measurements.

 

https://en.wikipedia.org/wiki/Bell's_theorem

 

Bohm's Wholeness and the Implicate Order was discussed above.

https://en.wikipedia.org/wiki/Many-worlds_interpretation