Thanks BenLurkin.
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Posted on 10/04/2022 4:28:19 AM PDT by FarCenter
Where was Sheldon Cooper??
“They both won and didn鈥檛 win the Nobel Prize for Quantum Physics.”
馃憤馃憤馃榿
“Zeilinger has gone on from basic research to pioneer quantum encryption.”
Yes, this is a well deserved prize. It has both practical applications such as with quantum computing.
It also tells us something very fundamental about the universe. It proves it is not a pre set clock with only one possible path. The future is ours to create, not pre-determined.
Fisicks be raciss!
No comments have been forthcoming from Nobel prize laureate, Cal Tech physicist Dr. Sheldon Cooper, physicist Dr. Leonard Hofstadter, astrophysicist Dr. Rajesh Koothrappali, or Mr. Howard Walowitz from the Cal Tech Engineering Department.
Dr. Sheldon Cooper is distraught at the thought that three experimentalists have one the Nobel.
Dr. Leonard Hofstadter, Dr. Rajesh Koothrappali, or Mr. Howard Walowitz are expressing considerable satisfaction.
They shouldn't have given it to the Frenchman.
He only worked on aspects of the problem.
That last episode of The Big Bang Theory rang false, but I guess they wanted to end it on an emotional, "heartwarming" note.
Read later.
Yup! When I heard the news I thought “It’s about time he won!!”
So, does this mean that you exist only if I perceive you? Do I exist only because I am self-conscious? If I am in a coma, or under propofol, I do not exist? Am I the same person you perceive or is the me which you perceive a different entity from that which I am self-conscious of.
Answers not in order:
Maybe
Yes
No
Perception and self-conciousness are fascinating. We all have a personal view of ourselves, which I expect will not line up with anyone else’s view of us.
Kinda like when we hear ourselves on the radio or TV.
Last year, in 2022, John Clauser, Alain Aspect, and Anton Zeilinger were awarded the Nobel Prize in physics. Their groundbreaking work was built upon one of the most significant discoveries in the history of physics: Bell's Theorem, which was originally formulated by the late John Stewart Bell. In this video, we delve into the reasons why Bell's Theorem stands as one of the most important and perplexing results in the annals of physics. Join us as we celebrate the achievements of these three remarkable scientists who, through their contributions, laid the foundation for cutting-edge technologies rooted in quantum information.Bell's Inequality: The weirdest theorem in the world | Nobel Prize 2022 | 13:21
Qiskit | 131K subscribers | 1,877,293 views | October 7, 2022
Transcript 0:00 路 - Hi, my name is Olivia Lanes from IBM Quantum 0:02 路 and I'm here today to celebrate and explain the relevance 0:06 路 and the excitement around the 2022 Physics Nobel Prize. 0:11 路 So, just a few days ago, 0:12 路 the Physics Nobel Prize for this year 0:15 路 was awarded to three gentlemen: 0:17 路 John Clauser, 0:18 路 Alaine Aspect, 0:19 路 and Anton Zeilinger. 0:20 路 These gentlemen won the award for groundbreaking research 0:24 路 and experiments in quantum mechanics. 0:27 路 And all of this research was based 0:28 路 upon some original experiments that were done 0:31 路 by a gentleman named John Bell, 0:34 路 who tragically passed away 0:35 路 before he was able to see a Nobel Prize 0:38 路 or something of that magnitude. 0:40 路 But we are going to discuss it here today 0:41 路 and show why the experiments that were built 0:44 路 off of John Bell's original theorem are so important. 0:47 路 So we have to go back a little bit 0:49 路 in history in order to set the stage 0:51 路 and the context of why this is so important. 0:53 路 So, in the sixties, 0:55 路 John Stewart Bell was reading the EPR paper 0:59 路 which was a paper written by Einstein 1:02 路 and some of his colleagues explaining how they believed 1:05 路 that quantum mechanics was an incomplete theory. 1:08 路 Now, in quantum mechanics, 1:09 路 we say there exists this thing called the "wave function." 1:14 路 Which describes all of the properties 1:16 路 of your quantum system. 1:17 路 And upon measurement, it collapses into a single quantity. 1:22 路 That was only described probabilistically 1:24 路 before you measured it. 1:26 路 Anyway, in the paper, 1:27 路 Einstein said that quantum mechanics 1:30 路 must be an incomplete theory 1:31 路 because this could not be possible. 1:33 路 This would necessitate things that he could not 1:35 路 believe to be true. 1:37 路 And so we were either missing something in the theory, 1:41 路 somehow these particles were interacting 1:43 路 in a way that we didn't actually understand 1:45 路 or didn't have a description for yet. 1:47 路 But basically it was not finished. 1:49 路 And sometime later, 1:51 路 John Stewart Bell was reading this paper, 1:53 路 and he sat down and he wrote what is come to be known 1:57 路 as "Bell's Theorem." 1:58 路 In just a few lines of algebra, 2:00 路 he showed that if you only assume two things. 2:04 路 Those things being local realism. 2:07 路 Locality, meaning you can't travel faster 2:09 路 than the speed of light. 2:10 路 And realism, 2:11 路 which means that things have definite values 2:14 路 whether or not you measure them. 2:16 路 So for instance, we always say, 2:17 路 "if a tree falls in the forest 2:19 路 and no one is around to hear it, does it make a noise?" 2:21 路 If the answer is yes, 2:23 路 this would be an example of definite realism. 2:26 路 So he assumed only those two things 2:29 路 in his mathematical derivation. 2:32 路 And he was able to show that there are certain qualities, 2:35 路 quantities that you can measure that are bounded 2:39 路 by classical physics if you assume only local realism. 2:43 路 And essentially he was able to show, 2:46 路 on paper at least, 2:47 路 that quantum mechanics was incompatible 2:50 路 with any classical theory. 2:52 路 So anything that was basically including local realism 2:57 路 could not possibly work with quantum mechanics. 3:01 路 So now a few years later, 3:04 路 John Clauser came along and he was reading Bell's Theorem 3:10 路 and he thought that this should be something 3:12 路 that was able to be done experimentally. 3:15 路 So he was able to actually perform an example 3:19 路 in the laboratory for the first time, 3:21 路 a violation of this equality and show 3:25 路 that indeed, nature behaves as weirdly as predicted. 3:30 路 And so in essence, 3:32 路 Einstein was wrong in his EPR paper. 3:35 路 And this led to groundbreaking work later on 3:38 路 from Alaine Aspect who was able to perform 3:41 路 even more tests of Bell's inequality 3:43 路 and close some of the loopholes, so to speak. 3:46 路 And then this led to Anton Zeilinger 3:48 路 who was able to show the demonstration 3:51 路 for the first time of quantum teleportation. 3:53 路 Which is not what you might think. 3:55 路 it's not at all like Star Trek. 3:56 路 People are not teleporting across the room, but instead, 3:59 路 quantum teleportation is a way to entangle 4:02 路 or correlate quantum particles 4:04 路 in such a way that you can transfer quantum information 4:07 路 from one to another. 4:10 路 So in order to really understand why this is so important 4:13 路 and why this is so groundbreaking, 4:15 路 I want to go back and look 4:16 路 at a very specific demonstration of Bell's tests for you. 4:20 路 There are in fact many different Bell type theorems 4:23 路 that can be shown but we're gonna look at 4:25 路 really one specific one today 4:27 路 which is called the CHSH test 4:30 路 or the CHSH inequality. 4:32 路 And so what you need to do 4:34 路 for this thought experiment is first imagine 4:37 路 a person named Alice 4:40 路 and a gentleman named Bob 4:44 路 and they are standing some distance far away 4:46 路 from one another. 4:48 路 And then there's another guy in the middle, 4:50 路 let's just call him Victor. 4:52 路 And he's going to send a particle 4:56 路 to Alice and to Bob at the same time. 5:01 路 And Alice and Bob are going to perform, 5:03 路 every single time this happens, one of two measurements. 5:06 路 They're going to either measure the X projection 5:11 路 or the Y projection of this particle. 5:15 路 And so you can only measure one at a time. 5:17 路 So in order to have a good understanding 5:20 路 of the measurements of both, 5:21 路 they have to perform this experiment multiple times. 5:25 路 And it's important to note that every time Alice 5:26 路 receives a particle, Bob also receives a particle. 5:29 路 And again, the only thing really assuming here, 5:32 路 is local realism. 5:33 路 So these particles are not moving faster 5:35 路 than the speed of light. 5:36 路 Bob and Alice can't call each other faster 5:38 路 than the speed of light and communicate information, 5:40 路 nothing like that. 5:41 路 And these particles also have these definite values 5:44 路 that are either going to be one or minus one 5:47 路 because, let's just say they are, they're normalized. 5:50 路 So the values for X and Y for Alice 5:53 路 and X and Y for Bob, 5:54 路 can only be one or minus one. 5:57 路 They are binary. 5:58 路 So now at this point, 6:00 路 we need to write down what is known as the CHSH value. 6:05 路 So, this is like so, 6:07 路 Alice's measurement of X times 6:10 路 Bob's measurement of x 6:12 路 plus Alice's measurement of X, 6:15 路 Bob's measurement of Y, 6:18 路 Alice's measurement of Y, 6:20 路 Bob's measurement of X. 6:22 路 And then you subtract from that sum 6:24 路 Alice's measurement Of Y 6:27 路 and Bob's measurement of Y. 6:28 路 And it really doesn't matter where this quantity comes from. 6:33 路 The fact is, if we look at it a little bit closer, 6:36 路 we can factor out 6:40 路 the Alice quantities 6:44 路 from the Bob quantities. 6:46 路 And you see, we would get something like this. 6:53 路 And I drew this for you here, 6:56 路 a little equal sign there at the end, 6:57 路 so you can see that either this value 7:00 路 every time the experiment is performed 7:02 路 or this value is going to be equal to zero. 7:05 路 Because either you are measuring one minus one 7:09 路 or you're gonna have minus one plus one. 7:12 路 The values again, can only be one or minus one. 7:14 路 So the maximum value this quantity could take on 7:18 路 is equal to two, 7:20 路 at most. 7:21 路 But remember, 7:22 路 we're running this experiment many, many times. 7:24 路 So say we ran this experiment, you know, 7:27 路 hundreds of times and we're measuring 7:28 路 a few different values every time Alice is measuring X and Y 7:32 路 and a few different values 7:32 路 every time Bob is measuring X and Y. 7:35 路 That means that this is actually bounded by two again 7:39 路 but it can be equal to 7:42 路 two or less than two. 7:44 路 Once we take the averages, 7:45 路 and that's what these little brackets mean here. 7:48 路 We're gonna take the average of all of these measurements. 7:52 路 All right. 7:53 路 So this value has to be less than two. 7:56 路 If the only assumptions we are making are locality 8:02 路 and realism. 8:05 路 However, let's think about this experiment again. 8:08 路 Slightly differently. 8:11 路 Let's now assume that instead of a particle, 8:15 路 just a random object Alice and Bob are receiving, 8:18 路 they are going to be receiving entangled qubits. 8:24 路 These are qubits. 8:27 路 It doesn't matter how they were entangled originally 8:29 路 at the beginning, let's just say that they are. 8:33 路 What you're actually going to measure, 8:35 路 once you perform this experiment hundreds of times, 8:40 路 is that this quantity is going to be approximately 8:42 路 2.8. Not two, not less than two. 8:46 路 We know for sure that 2.8 is greater than two. 8:51 路 Which means that if these qubits obey the laws 8:54 路 of quantum mechanics, which we know they do, 8:57 路 quantum mechanics violates Bell's inequality. 9:00 路 It is incompatible with local realism. 9:05 路 So either something is moving faster 9:07 路 than the speed of light or, 9:10 路 these particles do not have definite values 9:13 路 before they are measured. 9:15 路 And now a lot of people, I think, 9:17 路 misconstrue what this actually means. 9:20 路 Some people think that this opens the gateway 9:22 路 for faster than light communication. 9:24 路 This is not the case. 9:26 路 Let me be very clear about that, 9:27 路 because this is a really easy mistake to make. 9:30 路 Bob and Alice are not communicating 9:33 路 with each other faster than the speed of light. 9:34 路 There's no possible way to do that. 9:37 路 The particles become entangled, 9:39 路 and when you measure them, say Alice measures one, 9:42 路 we know that instantaneously the other particle 9:45 路 is going to choose the opposite 9:47 路 correlated value, negative one. 9:49 路 But that does not mean that Alice and Bob 9:51 路 are able to communicate with each other 9:52 路 faster than the speed of light. 9:53 路 No information is being transferred at that speed. 9:57 路 So that's really important to know. 9:59 路 And since there's no evidence of anything 10:02 路 in the universe traveling faster than the speed of light, 10:05 路 the way that most scientists have interpreted this is 10:08 路 that we have to give up the idea of realism. 10:11 路 These quantum particles actually do not have 10:15 路 values that are specific to them before you measure them. 10:19 路 They are instead described by what Einstein 10:22 路 (chuckles) called and resented the "wave function." 10:25 路 And so it has some probability of being 10:28 路 in either state one or minus one before you measure it. 10:32 路 And you might be wondering, 10:33 路 where does this 2.8 number come from? 10:36 路 Certainly it's greater than two, 10:38 路 and we can understand 10:39 路 that it does indeed violate this inequality. 10:41 路 But where does this 2.8 come from? 10:44 路 And so, if you're interested, 10:45 路 I challenge you to go online to the Qiskit textbook, 10:48 路 and the link is linked below in the bio, 10:51 路 and to try your hand 10:53 路 at this experiment for yourself right now. 10:55 路 There is a tutorial actually already published online 10:58 路 on the Qiskit textbook, on the CHSH inequality. 11:01 路 And you can run the experiment from your couch 11:03 路 or wherever you are right now, 11:05 路 and see indeed that you are going to get a number 11:07 路 that is approximately 2.8. 11:09 路 And while you might not win a Nobel Prize 11:12 路 for doing this because lots of experiments 11:14 路 in this vein have been done at this point, 11:16 路 I still think it's miraculous 11:18 路 that we have gone in a few decades 11:21 路 from an experiment that is Nobel Prize winning 11:25 路 to an experiment that you can do, 11:27 路 that I can do, from anywhere in the world. 11:29 路 So what this showed is that quantum mechanics 11:32 路 is even weirder and even more mysterious 11:37 路 than we initially thought it was. 11:40 路 It's completely incompatible with any classical theory 11:44 路 that we can come up with. 11:46 路 If you assume locality and realism. 11:48 路 And reading this you might think that makes no sense. 11:52 路 That's impossible. I hate it. 11:53 路 But what these gentlemen who just won the Nobel 11:56 路 were able to do is read this, this proof, 11:59 路 this thought experiment, 12:00 路 and then go to the lab and actually demonstrate 12:03 路 it in real life. 12:05 路 So it's not just weird on paper, 12:07 路 it's weird in the real world. 12:10 路 Quantum mechanics brings us to the brink 12:13 路 of the impossible and it brings us to the point 12:16 路 at which we shouldn't be able to 12:19 路 fully comprehend what's going on, but no further than that. 12:23 路 And so that's why it's just a really, 12:25 路 really exciting time for us in the field today. 12:28 路 Because these scientists showed 12:31 路 that not only is quantum mechanics weird and mysterious 12:35 路 and counterintuitive, it is practical. 12:39 路 And everything that we are working on 12:40 路 today at IBM Quantum, 12:42 路 everything that other quantum computing companies 12:44 路 are working on, quantum sensing, quantum cryptography, 12:47 路 are all built upon these experiments 12:50 路 which showed for the first time that entanglement, 12:53 路 quantum entanglement, 12:54 路 really is something that is so fundamentally different 12:58 路 than classical physics can describe. 13:01 路 So I want to wish congratulations 13:04 路 to the Nobel Laureates, again, 13:05 路 from myself and everybody here at IBM 13:08 路 and thank them for their work 13:10 路 and for our jobs as well. 13:13 路 (gentle music)
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