How Physicists Proved The Universe Isn't Locally Real - Nobel Prize in Physics 2022 EXPLAINED

On October 4, our terrestrial aspect, John Clauser and Anton Zeilinger received the Nobel Prize in Physics for proving that the Universe is not

locally

real

. What I love about this story is that it's the story of literally some of the smartest people who have ever lived. I lived in confusion and how Einstein was finally proven wrong, which doesn't happen very often. This idea of ​​what is

locally

real

is made up of two concepts. Locality is the idea that things are only affected by their local environment. You can't press a switch. in another galaxy hundreds of light years away and instantly see the results here because nothing, not even information, can travel faster than the reality of light, although it is much more difficult to explain and that is the approach of the Nobel Prize foreigner near the beginning, around the 1930s, where there were two paradigms, two ways of thinking about the

physics

of small things like particles, atoms, electrons, photons, etc., the view of Einstein and many others was that the Universe is real, particles, atoms and electrons have definite properties that are inherent to them, regardless of whether they are inherent.

It is essentially measured if a tree falls in the forest and there is no one around to hear it, it actually makes a noise and then there was an opposing group. Antirealists advocated by people like Bohr and many others, particles have properties that haven't really made a decision until you actually go out and measure them, they exist on a wave function of possible states and only when you actually take a measurement do they actually make a decision . The famous example here is Schrodinger's cat which is alive and dead until you look inside the box and finally go to prison abroad culminated in a famous article called epr paper where Einstein podolki and Rosen proposed a thought experiment that, According to them, it perfectly highlighted quantum mechanics at best it was incomplete and at worst it may be totally wrong their thought experiment focused on an idea from quantum mechanics called entanglement that the property of two particles can be inherently related their line of reasoning for his thought experiment he started with well we know that energy is conserved things do not suddenly start moving in one direction unless someone or something pushes or pulls them, nor do they suddenly start spinning by jumping up and down or doing anything else. unless someone else is directly affecting them number two if we start with a small quantum mechanical particle that is not spinning or moving or doing anything else, let's imagine that particle spontaneously breaks into two, if we look at one of those pieces where breaks up and we discover that it is moving to the right, we know instantly that the other particle must be moving to the left to maintain momentum or if we had looked at it and discovered that it was spinning in one direction, perhaps clockwise of the clock, we would instantly know that the other particle must be spinning counterclockwise to conserve angular momentum.

You would be confused if you looked at this system and if you saw both particles suddenly moving to the right, your intuition would tell you that some external force must perhaps have hit them or for the same reason, although it may be less intuitive because most people don't think about angular momentum or spin, you would be equally surprised. If you saw both particles spinning in the same direction, you would assume that something must have hit them and caused them both to start spinning. Step 3 of quantum mechanics here says that these states are impossible to know before you go out and measure them if you separate them. particles light-years away and you measured one, say, and found that it was spinning clockwise, you would know instantly, even if that particle were universally shaped, that its counterpart must be spinning counterclockwise. clockwise, but how could this be if they actually only take a defined value? when you measure them and the other always needs to be the opposite of what you measured, then the particle you measured would need to instantly communicate with its partner and tell it to take on the opposite value permanently.

Einstein argued that this was impossible. because it would have violated locality and meant that the information had instantly traveled faster than the speed of light to tell the other particle to collapse its wave function and decide which direction it was spinning, instead he argued that there should have been made a decision in From the beginning, when it was created, we just didn't know it or we weren't smart enough yet to find a good way to measure it. He called this unknown knowledge hidden variables and said that this was the piece of quantum mechanics that was still available. to be completed, and for about 30 years

physicists

really split into two groups, either siding with Einstein or siding with cool, mainly because no one had really come up with a good theoretical or experimental counterargument to Einstein's paper.

Einstein that was published until about 1964, when John Bell, an Irish physicist taking a year off from his work at CERN, began doing his own more theoretical work, these works later called Bell's theorem or inequalities of Bell, of which there are many different forms, but the underlying idea is to try to get The

universe

to choose a side tells us whether those hidden variables and Einstein are right or tell us whether a wave function really exists and whether quantum mechanics is real. Now this depends a lot on what happens to quantum objects when you actually go out and measure them.

So let me introduce you to the idea of ​​a particle of light called a photon. Photons have a property called polarization that describes which direction the light wave oscillates through space, either vertically or horizontally or potentially somewhere in between if you wanted to measure which state. If there was a photon, you would pass it through a polarizer that lets vertical light through in one orientation or will only let soft Horizon light through in another orientation, but at least the detector you put behind that polarizer knows what kind of light it is. detecting if you shot with randomly polarized light, part vertical, part horizontal, part in between, placing first a vertical polarizer and then a horizontal polarizer, then you would expect to see correctly that no light reached your detector because all polarization angles had been blocked, you can You see this effect when you use polarizing films that are the same ones you find in a pair of polarized sunglasses.

By orienting two polarized films at 90 degrees to each other, you don't see light emerging through them. The interesting thing here is that if you place a third polarizer between these two, suddenly and I think quite counterintuitively you start to see more light, this is fundamentally because measuring a particle changes its state allowing light to slip through. through the final polarizer where you normally couldn't, so you start. see more light than you would expect, so let's get back to the story at this point in the story. Belle's work was even more theory and thought experiment than anything else and that, classically, is the problem with theorists if you look at them from a distance.

It just seems like a wizard trying to argue with you

physicists

really needed to find a way to complete an experimental measurement. One of the earliest, most elegant, and now widely evidenced extensions of Belle's theorem work is John Clauser's chsh inequality. The Nobel Prize winner we're talking about here, Michael Horn Abner Shimini and Richard Holt, and their work here makes this theorem that Bell developed actually experimentally testable. The scenario you describe is similar to the one we talked about before where two entangled photons are sent. opposite directions to Two observers, Alice and Bob, both Bob and Alice get a polarizer to play with in their settings that helps them determine which polarization the light is actually in and finally, Alice and Bob are randomly told to rotate their polarizers over time and record where photons successfully or unsuccessfully reach their detectors, what we are interested in doing here is counting how often Alice and Bob agree on whether or not they have seen a photon, if Alice and Bob misalign perfectly their polarizers, then both should always see a photon or neither should see a photon, they should always agree on whether the photons arrived or did not arrive, if, however, Alice and Bob align their polarizers, Alice should see a photon and Bob shouldn't see one. o Bob should see a photon and Alice should not see one.

The interesting part occurs at angles between these positions if the

universe

is real and the photons are truly independent. Alice and Bob's agreement rate should move linearly between complete agreement and complete disagreement. If, however, the universe is not real, we should expect to see a higher agreement rate than would be expected, just as in our setup. three polarizers, except now our polarizers are on the other side of the Universe from each other and the same photon does not pass through both or Is this can only be true if the particles are still actually connected to allow each other to know what polarization state they should be in? be, so that the measurement in one actually affects the measurement in the other and in 1972 it was John Clauser who built the first experimental setup? able to make this measurement in the article he published that year this was the figure he showed exactly coinciding with the prediction of quantum mechanics, demonstrating that the Universe is not locally real, that Einstein's deterministic vision was incorrect and a history from this point he says: I'm not sure if it really happened or not, so excited to demonstrate the outcome clause he runs to Richard Feynman's office to tell him the news and, in classic Feynman style, Feynman kicks him out of his office for always doubting quantum mechanics and tells him well, now, get it.

Continuing with some real

physics

, fellow Nobel Prize winners Elaine Aspecto and Anton Zollinger closed important gaps that remained within this experiment, as well as demonstrating that quantum entanglement can be transferred to other particles in a process called quantum teleportation. All this to say that without a doubt. The universe

proved

to be stranger than Einstein had imagined. All of these phenomena are really the backbone of what is driving the modern quantum computing revolution. The idea that at some point in the near future, quantum computers will surpass classical computers because they have this capability. The inherent advantage is that, at their core, the particles that run them communicate with each other, although this does not prove it, and I can absolutely forgive anyone who, upon first hearing it, thinks that people can now communicate faster than the light, although it would be possible. to derive some fast and light communication which unfortunately is where the field unanimously says no, this is ultimately because the core of this phenomenon is the inherent randomness in the source of that photon or generation of entangled particles and then also in those measurement points that each photon will have. achieve it or not achieve it through a polarizer, each photon will be created in some combination of states that ultimately that combination of states will be unknowable until it is measured, there is no way to load information into that communication channel and As a result, there is no way to violate Einstein's fundamental contribution, which is that the speed of light is a fundamental limit in the universe, which is absolutely correct and I think Keith Einstein is reasonably happy, thank you stranger.