WHAT IS ENTIREMENT IN THE QUANTUM WORLD?

Quantum mechanics is very strange. First, there is this unusual particle-wave duality in which sometimes quantum objects behave as point particles and sometimes as a wave propagating into the environment. This behavior even depends on whether you view quantum objects as particles. There is also a superposition state in which particles are in two different quantum states at the same time, which is closely related to quantum entanglement. There are cases where even a single particle behaves like a wave, as in the double-slit experiment, and it is possible to rewind time, in a sense, at least for the particles, with a quantum eraser.
The strangeness of quantum physics does not end there. For example, we question whether faster-than-light communication is possible with quantum entanglement. Due to Heisenberg's uncertainty principle, we wonder why we cannot know two different quantum states, such as the position and momentum of a particle, with certainty at the same time. We even ask whether Schrödinger's cat is both alive and dead, or is it either alive or dead? All these extraordinary properties also get “entangled” in quantum entanglement.
WHAT IS QUANTUM MEASUREMENT AND ENTRACTION?
In quantum entanglement, which Einstein criticized with the words strange effect at a distance, if the state of one of the two entangled particles changes, the state of its entangled partner changes accordingly and seemingly suddenly. No matter how far away the particles are, they affect each other instantly. Although this definition is not entirely accurate; because we don't know what particles are. As the uncertainty principle states, when measuring a quantum object, we do not know exactly what we are measuring, and we call this the quantum measurement problem. After all, there is a limit to expressing quantum mechanics in everyday language.
WHAT IS ENTIREMENT IN QUANTUM PHYSICS?
Just as there is a relationship between you and your romantic partner, there is also a relationship between entangled particles. Moreover, as we will see shortly, this relationship is like the particles being knotted or tied together with a rope. For example, if your loved one has an accident, you will be affected by it, and if the state of one of the entangled particles changes, his/her partner will also be affected. Of course, the relationship of particles in quantum mechanics is much more extraordinary than this.
Take electron spin for example... Since electrons are bipolar magnets, they have two magnetic poles. Therefore, electrons rotate around themselves clockwise or counterclockwise. Since there is no rotation in quantum physics as in classical physics, we call the two possible spin directions of electrons spin down and spin up. So that if one of the entangled electrons is in a spin up state, the other will definitely be in a spin down state. This is Let's say you have a pair of gloves and one of the gloves will be right-handed and the other will be left-handed. Just as a pair of gloves cannot have two left pairs, entangled electrons do not have the same spin. Likewise, the parts of the glove will also be related to each other. On the other hand, due to the uncertainty principle, we cannot know in advance in which direction a particle will spin and we cannot measure the current state of the particles precisely. For this reason, we can only calculate the probabilities indicating which spin direction the electrons will be in.

In summary, the relationship between entangled electrons is different from the relationship between gloves belonging to the same pair. In this context, in quantum mechanics, we represent the relational probabilities between particles with statistical relations. Entangled electron spins are also statistically correlated with each other. So how does quantum entanglement work?easy to understand at first glance.
WHAT IS SUPERPOSITION AND ENTRACTION?
At first glance, entanglement is like boxing the right one of a pair of gloves and sending it to your friend by courier. If you send him the right one, you will only have the left one. When your friend opens the box and sees the right pair of gloves, he will understand that you will have the left one. As a result, it is clear in advance which pair of gloves will go to your friend. This information does not change whether your friend opens the box or not. Of course, this is valid if you tell your friend that you have the left one and you do not lie about it. 😉 This is not a joke; because in quantum entanglement the relationship situation is completely different.
We know that when electrons are entangled, they will definitely be in opposite spin. However, we cannot predict AND determine which electron will be in the spin-up state. You may think this is easy to solve. We measure one of the electrons and if we see that it is in a spin-up state, the other will definitely be in a spin-down state. Indeed, it is so in classical physics, but not in quantum physics; Because the spin of the electron you measure will only be known after you measure it!

This is because in order to fully entangle two electrons, it is necessary to isolate them from the environment. Thus, they do not physically interact with other particles and the environment. When they do not enter, they are not in a certain state such as spin down. The state of electrons that do not interact with the environment and that you do not measure is uncertain and they are in superposition. The probability wave function equation shows the spin probabilities of electrons. Therefore, electrons isolated from the environment have no specific state and only possibilities.
Electrons in superposition exist in a blurred state in both spin-down and spin-up states. That's why electron spin only becomes apparent when you measure it. Of course, the entangled partner of the electron you measure will have the opposite spin, but this is determined by the spin of the electron you measure. If we explain this with gloves; You cannot decide in advance that you will send your friend the right pair of gloves.

This will only become evident if your friend opens the box and sees that he has received the right one. Now you will say, but sir, I am the one who put the glove in the box to send it to my friend. So don't I predetermine that I send the right one? Because of the uncertainty principle, no, you can't do that, but I'll come back to uncertainty. So how do we know that there is such a thing as superposition in quantum mechanics?
WHAT IS ENGLISHMENT IN THE DOUBLE Slit EXPERIMENT?
The double slit experiment tells us two interesting things… We can think of probability waves as abstract mathematical waves because they represent probabilities. However, the electron waves reflected on the screen show that these are concrete. As a matter of fact, David Bohm created pilot waves like on the sea surface instead of probability waves. According to him, electrons were particles, not waves, and pilot waves actually carried them to the opposite curtain. We were seeing pilot wave interference on the screen, not electron waves. I'll come back to this theory in terms of entanglement, but now let's move on to the second thing the experiment teaches us:

Except for Bohm's pilot wave theory, even a single electron behaves as a wave. Unless we look at the slits, it is not clear which slit it passes through. Therefore, it interferes with itself as a probability wave in superposition and passes through both slits. In summary, the double-slit experiment has shown us that superposition, which is the basis of quantum entanglement, is real. It is a non-local wave until a particle measures it, and only then does it become a local object, a particle.
WHAT IS REMOTE EFFECT AND ENTRACTION?
Now we will look at the issue from a remote effect perspective. Next we will consider Bohm's pilot wave (hidden variables) theory. We will then view entanglement from the perspective of string theory and investigate why we have not been able to develop a theory of quantum gravity that unifies gravity and quantum mechanics. Finally, we will discuss how to explain entanglement in new physics without remote effects. Let's start with Albert Einstein. In 1935, Einstein designed the EPR experiment with two late scientists (Boris Podolsky and Nathan Rosen), named after the initials of the physicists' names.

Einstein's purpose was not to deny quantum physics. As a matter of fact, he is the second founder of quantum physics after Max Planck, with the photoelectric effect formulated in 1905. On the other hand, Einstein thought that quantum mechanics was an incomplete formulation and could not explain nature. The purpose of the effect-at-remote (EPR) experiment was to demonstrate this. As a result, in quantum entanglement, even though there is an infinite distance between two entangled electrons, they affect each other instantly.

On the other hand, physical forces propagate through spacetime at the speed of light, and in classical physics, particles affect each other from a distance. Physical effects originate from one particle and travel through space to reach another. This is how physical interactions occur. So much so that in order for particles to suddenly affect each other in entanglement, interactions must propagate faster than light, even at infinite speed. Since nothing can go faster than light, quantum mechanics is wrong and therefore incomplete.