Weizmann Institute scientists affected the spin of a single atom through measurement
One of the well-known principles of quantum theory says that a system can be in a large number of states at the same time. That is, it exists in parallel realities, a phenomenon known as "superposition". The superposition exists as long as we do not observe the system or measure it in some way. When we measure the system, it "collapses" based on the measurement and stabilizes in one reality. The reason why we experience the world around us in only one reality is related to the fact that we are constantly measuring it. For example, we measure the position of letters on a computer screen by looking at them.
The principle of superposition was first demonstrated by Otto Stern Walter and Gerlach in 1922 using spins (small magnets) of silver atoms. Such spins can exist in superposition, that is, they point in different directions at the same time. Dr. Roi Ozari and research students Yanon Glickman, Shlomi Kotler and Nitzan Akerman, from the Department of Physics of Complex Systems at the Weizmann Institute of Science showed how through "observation" a measurement of a single atomic spin is made. The results of the study were published in the scientific journal Science. The team members illuminated the atom, measured the photon it emitted as a result of the illumination, and showed that the atomic spin collapses from the superposition into a single reality, where it points in the direction the atom emitted the photon.
They later showed that when they measure the polarization of the emitted photon, they thereby determine the spin direction of the atom. That is, the observer not only affects the result, but can also determine in advance how the measurement will affect the measured system.
In the last experiment in the series, the scientists showed that the spins of the measured atom and the photon emitted from it are in an entangled state. That is, even after they move very far from each other, every measurement of one of them immediately affects the other.
This experiment is an important step towards understanding the meaning of measurement in quantum systems.
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A question to the experts.
Assuming that the directionality of the electron's spin can be controlled and when measuring it, it provides the same spin, doesn't this allow the transmission of coded information at a distance between two conjugated electrons?
Hello Kobi
There are those who see one moon and there are those who see a smiling moon that they drew on, depending on the parallel worlds on which we stand, depending on how our consciousness moves in time, and depending on who knows how to play with it. It is difficult to explain to humans because they do not see it directly that one sees this way and another sees another and they meet in a place where they usually see the same thing. There is a convergence or "collapse in time" of parallel worlds, respectfully
Kobi
"My feeling on the matter is that they are trying to avoid the matter of "awareness" perhaps because it is a subject that scientists have no idea about." - Handsome. Because of "this thing" that determines the things that follow it, and defines them, we cannot understand what the meaning is that our intervention in nature and the definition of the disturbance in the device as X - creates. It is impossible to understand because there is no definition for the concept of awareness and we have no ability to artificially generate intelligence and awareness. And therefore there is no way for science to deal with this question. This question is addressed to the philosophical field and its practitioners.
Uri, as Noam mentioned, the question is how the wave function collapses. However, after it has already collapsed again, it is in a defined state and given to anyone who measures it from here on out. And that explains your question about seeing robots and animals (Who told you that awareness of the Earth doesn't count, Einstein already asked "Does the moon only exist because some mouse is looking at it?" The answer they gave him is that it turns out yes.)
When you say "measurement" it actually means that someone is measuring. Otherwise, the term "measurement" would have no meaning because nothing has yet been measured and the system can remain in superposition as it has been until now. My feeling on the matter is that they try to avoid the matter of "awareness" perhaps because it is a subject that scientists have no idea about.
@Ori, according to the rules of angular momentum connection, spin can be defined for atoms. For example, a bosonic atom can be obtained despite the fact that it is known to consist of fermions.
@Koby, the open question is how the wave functions collapse, the fact that this happens is empirical. Of course, the term collapse is arbitrary, and its use is for the purpose of creating a common language of a known phenomenon.
Kobi, thanks, but the claim that "awareness" is the one that causes the collapse sounds clearly improbable, if that really was the case then how do you explain the fact that animals without awareness manage to see the picture of the world around them and behave accordingly? How do you explain a vision of robots without any awareness that know how to analyze their environment?
It is quite clear to me that the collapse of the system is caused by the measurement itself (the interaction between the particles of the system and the particles that measure them) and not as a result of an external look at the measurement results which exist in any case even if no one looks at them.
Oh I almost forgot, thanks.
Dear Mr. Kobi, Hello.
In my opinion, the movement backwards and forwards in time explains the duplication and insertion of the superposition and the transfer of information, and that in itself is a proof, thank you (what else am I bothering about, only that in itself does not prove anything)
Ori,
You asked a very good question. I'm not sure that the great scientists can answer you so firmly as they answered you here.
Well, as far as I know the answer to the question is still not completely closed. In the last book I read on the matter by Machio Kaku, one of the greatest scientists on the matter, he remained on the question.
What does turn out is that "awareness" is what causes the collapse. Not exactly an eye.
But what, there are people who are not so comfortable with the fact that awareness creates such a strange thing, so they invent things with great confidence. The fact that the particle moves back and forth in time and replicates is just a hypothesis, and besides that it doesn't solve anything.
I would also love to hear if anyone has a more in-depth and correct explanation for the question.
Uri, you understood correctly and they also explained it to you in the answers.
Thanks.
Dear Falstaff Hello
There are those who claim that time has several dimensions and not just backwards and forwards, but it's hard for me to imagine this at all in the field. Thanks
Lucky that the particles don't turn sideways in time, only back and forth. And from the fact that they manage to reverse time I conclude that they are not of the female sex.
Thanks.
Okay thank you.
Thanks.
Thank you for not blocking me every time I mention that something also goes back in time, thank you
We thank you for the answer, by the way just a small comment, a bit funny that you sign your messages with the word "thank you". You are the one answering, what are you thanking for?
Uri, they observe the intention, check, send a light that hits and it has an effect.
And again the same principle only in spins, for a particle and if it is a photon or an electron, there is again movement backwards and forwards in time, therefore how many spins does the same particle (in superposition) have, you can say that it has an average of how many spins, but I am not sure about that, but what is happening that you check Same again, the spins, they converge and stabilize again on the test for as single a spin as possible, thank you
Thanks to the answers, that is, according to what I understood from your answers, the collapse is carried out (as I imagined) as a result of the measurement process itself, because of the light particles (photons) that hit the atom and thus performed the measurement, and not because there was a person there whose eye picked up the photons returning from there.
I don't understand why in most articles on quantum theory they try to create the wrong impression in the reader that it is the gaze itself that affects the state of the system ("the superposition exists as long as we do not observe the system").
By the way, when you talk about spins, don't you usually talk about a single electron? What is the spin of an atom?
Laurie:
The particle moves backwards and forwards in time many times and because of this it is duplicated into a super position, if you look at it with the help of a complex system whose behavior also depends on time, the particle will stabilize on the complex system (in this case the eye and the human body) and converge to a smaller number of possibilities, depending on the stability of the eye in the space and force that the particle needs to converge. Thanks
@Ori, of course there is no uniqueness to the human eye. The physical definition of a measurement is the determination of a specific property of a quantum system, for example the position or momentum of a particle. If you make the measurement with a photon, the system will collapse into a specific state depending on the wave function of the particle. To your question, the system will crash at the moment of measurement, and not when the person arrives an hour later.
If you translate that into information - you lose information when you sample anything
That is, there is no one-edged sword.
And if you translate it to choices in life - every choice you made lost another way
Now the question is whether it is desirable to always choose or stay in 'superposition' in life as a principle and the answer to this is in some cases...if you don't choose something you don't live.
Tam's question: "We measure the position of the letters on the computer screen by looking at them."
From the above sentence it sounds as if the collapse of the system into one state is created only as a result of the observation of a human eye (or human brain). This sounds "a little" strange and illogical to me, I want to understand for once, is the claim that a system collapses only when a person observes it? That is, if we place a device that measures the system and displays the result somewhere (for example on a computer screen) will the collapse occur at the moment of measurement? Or only when a person sees (after an hour, say) the results?
I don't understand why the observation of the human eye at the letters on the computer screen causes them to collapse? After all, with or without an eye, the particles on the screen (the letters) are continuously bombarded with photons that "measure" them, and some of the photons return back towards the chair in front of the computer screen, so what does it matter if a person sits in front of the computer and observes the results or not? After all, the measurement has already taken place (the photons that hit the screen and came back with the results).
I hope the question is clear.
An important step, but I didn't understand what's new here? ? ?