Posted on 07/22/2022 11:35:03 AM PDT by Red Badger
Two players leverage quantum rules to achieve a seemingly telepathic connection
It only looks like telepathy, but a quantum game harpoons our usual sense of reality. ====================================================================
The Moon isn’t necessarily there if you don’t look at it. So says quantum mechanics, which states that what exists depends on what you measure. Proving reality is like that usually involves the comparison of arcane probabilities, but physicists in China have made the point in a clearer way. They performed a matching game in which two players leverage quantum effects to win every time—which they can’t if measurements merely reveal reality as it already exists.
“To my knowledge this is the simplest [scenario] in which this happens,” says Adan Cabello, a theoretical physicist at the University of Seville who spelled out the game in 2001. Such quantum pseudotelepathy depends on correlations among particles that only exist in the quantum realm, says Anne Broadbent, a quantum information scientist at the University of Ottawa. “We’re observing something that has no classical equivalent.”
A quantum particle can exist in two mutually exclusive conditions at once. For example, a photon can be polarized so that the electric field in it wriggles vertically, horizontally, or both ways at the same time—at least until it’s measured. The two-way state then collapses randomly to either vertical or horizontal. Crucially, no matter how the two-way state collapses, an observer can’t assume the measurement merely reveals how the photon was already polarized. The polarization emerges only with the measurement.
That last bit rankled Albert Einstein, who thought something like a photon’s polarization should have a value independent of whether it is measured. He suggested particles might carry “hidden variables” that determine how a two-way state will collapse. However, in 1964, British theorist John Bell found a way to prove experimentally that such hidden variables cannot exist by exploiting a phenomenon known as entanglement.
Two photons can be entangled so that each is in an uncertain both-ways state, but their polarizations are correlated so that if one is horizontal the other must be vertical and vice versa. Probing entanglement is tricky. To do so, Alice and Bob must each have a measuring apparatus. Those devices can be oriented independently, so Alice can test whether her photon is polarized horizontally or vertically, while Bob can cant his detector by an angle. The relative orientation of the detectors affects how much their measurements are correlated.
Bell envisioned Alice and Bob orienting their detectors randomly over many measurements and then comparing the results. If hidden variables determine a photon’s polarization, the correlations between Alice’s and Bob’s measurements can be only so strong. But, he argued, quantum theory allows them to be stronger. Many experiments have seen those stronger correlations and ruled out hidden variables, albeit only statistically over many trials.
Now, Xi-Lin Wang and Hui-Tian Wang, physicists at Nanjing University, and colleagues have made the point more clearly through the Mermin-Peres game. In each round of the game, Alice and Bob share not one, but two pairs of entangled photons on which to make any measurements they like. Each player also has a three-by-three grid and fills each square in it with a 1 or a –1 depending on the result of those measurements. In each round, a referee randomly selects one of Alice’s rows and one of Bob’s columns, which overlap in one square. If Alice and Bob have the same number in that square, they win the round.
Sounds easy: Alice and Bob put 1 in every square to guarantee a win. Not so fast. Additional “parity” rules require that all the entries across Alice’s row must multiply to 1 and those down Bob’s column must multiply to –1.
If hidden variables predetermine the results of the measurements, Alice and Bob can’t win every round. Each possible set of values for the hidden variables effectively specifies a grid already filled out with –1s and 1s. The results of the actual measurements just tell Alice which one to pick. The same goes for Bob. But, as is easily shown with pencil and paper, no single grid can satisfy both Alice’s and Bob’s parity rules. So, their grids must disagree in at least one square, and on average, they can win at most eight out of nine rounds.
Quantum mechanics lets them win every time. To do that, they must use a set of measurements devised in 1990 by David Mermin, a theorist at Cornell University, and Asher Peres, a onetime theorist at the Israel Institute of Technology. Alice makes the measurements associated with the squares in the row specified by the referee, and Bob, those for the squares in the specified column. Entanglement guarantees they agree on the number in the key square and that their measurements also obey the parity rules. The whole scheme works because the values emerge only as the measurements are made. The rest of the grid is irrelevant, as values don’t exist for measurements that Alice and Bob never make.
Generating two pairs of entangled photons simultaneously is impractical, Xi-Lin Wang says. So instead, the experimenters used a single pair of photons that are entangled two ways—through polarization and so-called orbital angular momentum, which determines whether a wavelike photon corkscrews to the right or to the left. The experiment isn’t perfect, but Alice and Bob won 93.84% of 1,075,930 rounds, exceeding the 88.89% maximum with hidden variables, the team reports in a study in press at Physical Review Letters.
Others have demonstrated the same physics, Cabello says, but Xi-Lin Wang and colleagues “use exactly the language of the game, which is nice.” The demonstration could have practical applications, he says.
Broadbent has a real-world use in mind: verifying the work of a quantum computer. That task is essential but difficult because a quantum computer is supposed to do things an ordinary computer cannot. However, Broadbent says, if the game were woven into a program, monitoring it could confirm that the quantum computer is manipulating entangled states as it should.
Xi-Lin Wang says the experiment was meant mainly to show the potential of the team’s own favorite technology—photons entangle in both polarization and angular momentum. “We wish to improve the quality of these hyperentangled photons.”
doi: 10.1126/science.ade0429
Never mind Carol and Ted.
More precisely, reality doesn’t exist unless somebody observes it. This is the core of the Bishop Berkeley’s demonstration of the existence of God.
>> That is what is called a binary form of argument—”Either Alternative A or Alternative B must be true”. <<
>> There are always other alternatives. The fact that we do not know of them, in fact can’t even imagine them, is our shortcoming, not a shortcoming of nature. <<
Weeellll, not exactly. I’m not claiming that it tells us anything about the nature of God. But the infinite-universes theory is the atheist’s way of dodging the principle of first cause.
The next defense for the atheists, if they can’t assert an infinite number of parallel universes, I suppose, is to assert an infinite number of sequential universes. But that takes asserting the universe ends with a Big Crush, which is looking pretty baseless. It also means either you have to demonstrate that the physical laws and constants of these universes are somehow different from each other, or else you just have the very same highly improbably universe coming in and out of existence over and over again.
“There is no spoon...”
“God does not exist.” - Joe
“Joe does not exist.” - God....................................
“There are always other alternatives.”
How do you know that?
The Left simply denies the existence of objective reality. To them two plus two doesn’t equal four. Nor does it equal three or five. Two plus two equals whatever they say it equals. Right now. Today. Forget what they said yesterday, or last month, or last year ...
You're welcome.
A giant half truth.
Certain quirky things that appear present at the quantum level, are not things/states that any empirical evidence has shown to exist many levels up where you get to solid matter as we know it.
We do not empirically know any conscience existence at the quatum - elemental physics - level.
To infer “time” - a human measure of the transitions of physical existence, to occurances of actions at the quantum level is a scientific error, an anthropomorphization of the quantum fields of physics.
but once something is measured then the primacy of existence takes effect and objective reality is independent of and not created by emotionalism or wishful thinking (such as by lefturd loons subjectivism)
I don’t accept that. Humans measure things. I don’t recall hearing that the stars measure things. And what was there before the stars? Material that gave rise to the stars.
Reality is that which exists. To say that reality doesn’t exist is to contradict the nature of reality.
All this started from the uncertainty principle of Heisenberg, who said that one cannot assign exact simultaneous values to the position and momentum of a physical system. Then came the thought experiment of Schrödinger in which some say a “cat” is both alive and dead.
This has gone too far.
Reality is that which exists, regardless of whether it is perceived by a sentient being or not.
Here! Here!
A perspective I can agree with.
And to think, that some didn’t think I existed until I posted.... That’s different than somebody not “knowing about “ me.
Perception is not reality, reality can be perceived, but isn’t dependent on that perception.
Come on! Too much indoor time, get a sunburn!
Remember the sophomoric question, if the tree falls in the forest, and no one was there to hear it, did it make any noise?
Apparently, according to these guys, if there was no one there, there was no tree, and there was no forest.
It’s like the Ancient Greek who delighted in proving, mathematically, that you cannot outrun a turtle.
sounds like a language game. as in depends on what the meaning of is is.
or a pun
—Or who should I say has sent me—Moses.
—Tell them I am who I am has sent you—God.
Exodus 3:13-14
what about bob?
Ah, but Plato realized that there has to be a first observer, the ultimate cause. This is why John the Evangelist defined the Christ as the Logos-God, He by whom the universe was created.
King solomon made the same point in proverbs 8 only he used the word wisdom—except he says that wisdom was created and not a part of the God the creator. (This is a very testy subject. Someone should check the translations very carefully carefully.)
22 “The Lord brought me forth as the first of his works,[c][d]
before his deeds of old;
23 I was formed long ages ago,
at the very beginning, when the world came to be.
24 When there were no watery depths, I was given birth,
when there were no springs overflowing with water;
25 before the mountains were settled in place,
before the hills, I was given birth,
26 before he made the world or its fields
or any of the dust of the earth.
27 I was there when he set the heavens in place,
when he marked out the horizon on the face of the deep,
28 when he established the clouds above
and fixed securely the fountains of the deep,
29 when he gave the sea its boundary
so the waters would not overstep his command,
and when he marked out the foundations of the earth.
30 Then I was constantly[e] at his side.
I was filled with delight day after day,
rejoicing always in his presence,
31 rejoicing in his whole world
and delighting in mankind
Just like I thought. Other versions of the bible like the king james bible say:
Proverbs 8:22
King James Version
22 The Lord possessed me in the beginning of his way, before his works of old.
possession means something very different than created.
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