Amazing teacher. He's really taking his time to slowly introduce the meaning of "quantum " as it relates. He wisely decides not to explain all the other important aspects of quantum computing.
Plain (non-math) person here, who loves the promise of physics. Your historical review and your comparison of classical to quantum behaviors helped me to almost completely understand your talk. I'm sure we all are not your target audience, but I surely appreciate it.
Thank you for an interesting and enlightening lecture delivered perfectly. All the very best of luck with your continued work in this field. We will all look forward to seeing this progress
This is the OLD perspective. It's misleading to say "two places at the same time" and "both in the same place at the same time" we know this is not actually true The concept of "virtual particles" is ideal, they aren't anywhere and are just a waste of computation until some observer needs the data. The ideal example is the delayed eraser variants of the double slit and half mirror experiments - they work that way not because there is reverse causality, but because it is the most efficient way to configure this computed reality; someone MIGHT look at the data before it is erased.
The explanation of the nature of the duality of photons is quite remarkable and straightforward. It made me visualise the wave function collapse phenomenon like this: a widespread cloud makes a bolt of lightning hitting a single point randomly on the face of the earth. Still, when we use a lightning rod to detect it, the lightning bolt will be attracted to the very specified target. (here, it is downpouring heavy this week 😄). I am still pondering this idea.
A matter of fact, photons are the only things that humans can directly see. A photon is a bit of light. Human eyes are specifically designed to detect light.
I habitually hit Like even before properly listening to a Royal Institution lecture. It's only been up for 16 seconds now so I was lightning, or better yet, quantum fast to the whiteboard. Thank you for these wonderful classes. Will return to attend later this evening.
Ok, this language - "In several places at the same time" - just drives me crazy. It's severely misleading. Here is the thing. You have never, *ever* actually observed a particle to be in multiple places at the same time. Once you actually observe, you will find it in exactly *one* place. When you make a measurement, you will then find the system to be in an eigenstate of that observable. And those eigenstates form a basis, so yes, you can write down any state you wish - including the pre-measurement state - as a linear combination of those eigenstates. But *before* you make the measurement, the system isn't *in* any of those states. The system doesn't know what you're about to measure, so those states cannot possibly be of any particular importance in the description of the particle. It's the *measurement apparatus* that brings those states to significance. Before you apply the apparatus to the system those states are not "special" in any way whatsoever. Declaring them relevant to the system prior to the measurement is just a completely misleading way to describe things. What you should say is that, prior to the measurement, the system is not in a state that *has* a well-defined position (or whatever) value. When we make the measurement, the instrument *forces it* into a state that does. There is absolutely nothing mysterious about this - the quantum system is small and delicate, and the instrument is big and high energy by comparison (in order to be able to produce a result we can consume with our senses). Making it sound like some kind of black magic is a disservice to the audience.
Where does the Silq programming language come into this? I've read that it can be used in quantum computing, but I'm not clear on how - is it for modelling things like spin in experiments?
örnekte göstermiş olduğunuz elektronların kuantum yönünün sadece aşağı ve yukarı olması içinde bulunduğumuz galaksinin toplam çekimiyle ilgilidir. Bu durum yer çekimi denilen durumla da ilgilidir. Bizim galaksimiz referans alırsak diğer galaksilerde yön farklı olabilir.
Great talk, always wanted to catch up on this stuff & he explained it really well! I am interested as to why the best supercomputers can't calculate more than 30 spin cycle interactions in a molecule... Did he mean in real-time as surly it would be able to be calculated over a longer time at least, or is it one of those things where so much storage (RAM) is needed it gets out of hand?
Enjoyed this with a glass of wine, great "lecture", made me understand many concepts of quantum phisics that i cudn't grasp before. And of course, was a beautiful introduction onto how quantum computers are made, genious! Keep it up cuz!
If you found this interesting go watch the EEVdiscover interview with Prof. Andrea Morello from UNSW where he shows an antimony atom acting as a 3 qubit embedded in Silicon-28 wafer
once i started listening i had to start managing my tolerance to a little "tsssa" sound after 90% of every sentence David makes .. as most of them are facts.. "tssssa" .. urrrg such an interesting lecture.... maybe ill see if GTP3 can process the audio to remove the "tsaa". Maybe i could get AI to generate a learning process in which i could subject my self to fix my current state of mind... or maybe that sound "tsssa" is not really there.. and the current state of my cellular quantum processors are causing a protons uncertainty in a small molecule somewhere to appear in a new and unwanted place - producing a cascading effect emerging to the cellular level resulting in unwanted depolarisation of clusters of neurons to burst into existence. result: i'm hearing things. ( But i don't think i am....."tsaa") sorry David.
Is it right to say that observation is a quantum force? If you consider Shrodinger’s paradox it requires the observed and the interpretation of the observed or value. If there is no observation there is no interpretation or value. Subjectivity is an unknown and unique reference. The value of observation is subjective in both observed and observer’s reference which is unique in time and space. Is the observed subjective at the same time as the observer’s interpretation? Is this the root of chance or alignment?
We have 2 eyes yet we see one picture. Both eyes are capable of performing said task individually as well but function naturally in unison. This is like having your eyes closed but because the objects you could see are technically still there you can still see them. We endure quantum all the time every day we wake up. Our memories linked to nature we could reimagine a tree that was chopped down and because the tree was at some point in time witnessed by an observer another one will take its place as long as no one is around to observe it until it is in the exact same state as previously witnessed in real time in the past. That's borderline power of creation through manifesting thought. OK I'm legit sounding like a lunatic
He's neglected to mention at least two critical points. Quantum spin is not actually like a spinning top, and the reason schroedingers equation is so difficult to solve is because it is actually impossible to solve for more than 3 electrons because the many body problem is still unsolved
i absolutely hate when theorists try to explain the wavefunction collapse as if its a real thing. The wavefunction collapse is a manifestation of our knowledge, not the other way around.
Ibm has taken video of live atoms and is there in youtube and humanity has managed to slow down photo frames to femto range to take pic of moving light. So why not see the double slit experiment with using those tech ?
I was really wanting to watch this but every time he stopped to take a breath he was slapping his lips together/clicking his tongue or whatever and the noise was irritating me within 5 mins XD
i want to try to make a micro magnetic focused plasma toroid and calculate the mass of a electron and try to speed up the electrons up and make a gravitational wave im doing it at home but i could use some funding or tools
Dirac: When a state is formed by the superposition of two other states, it will have properties that are in some vague way intermediate between those of the original states and that approach more or less closely to those of either of them according to the greater or less 'weight' attached to this state in the superposition process. The new state is completely defined by the two original states when their relative weights in the superposition process are known, together with a certain phase difference, the exact meaning of weights and phases being provided in the general case by the mathematical theory. When a state is formed by the superposition of two other states, it will have properties that are in some vague way intermediate between those of the original states and that approach more or less closely to those of either of them according to the greater or less 'weight' attached to this state in the superposition process. The new state is completely defined by the two original states when their relative weights in the superposition process are known, together with a certain phase difference, the exact meaning of weights and phases being provided in the general case by the mathematical theory.
Feynman: It is just like the mathematics of the addition of vectors, where (a, b, c) are the components of one vector, and (a', b', c' ) are those of another vector, and the new light Z is then the "sum" of the vectors. This subject has always appealed to physicists and mathematicians. In fact, Schrödinger wrote a wonderful paper on color vision in which he developed this theory of vector analysis as applied to the mixing of colors.
So a 72 Qubit computer will only have 72 transistors attached to it, one transistor per qubit? And, we will not need billions of transistors any more like in a classical processor?
"The easiest person to fool is yourself", so the best and only available person to un-fool is your own self, embedded in Eternity-now Actuality Interval Totality of Self. I am you and you are me and we are all together in unity of QM-TIME Completeness Actuality.
I don't know anything about science and quantum mechanics, but can it be that dark matter actually is the state of the atom the moment it is flipping around? (kind of like when it's not in a "set"state). I mean... it probably could be, but idk if atoms have mass; but if they do it could be that all the mass of the "dark matter" is actually the mass of the atoms when they are flipping. And idk if that's how they did it but, if they measured the universe's mass with calculations and parameters, the "unknown" mass could be us not knowing that in reality a LOT of atoms were just flipping during the moment we were taking parameters for the math, in other words; if we can calculate the universe's mass with parameters, the final result would always be different, "proving" so that dark matter is "simply" the mass of an undefined state of an atom (that we can't individually/generally observe, so we also can't define its singular/general mass). But that is just a theory that I came up with and thus can (probably) never be accepted or denied until we can't observe the undefined state of an atom (including the mass).
The quantum state can last for 30 seconds?! Put enough of such quantum assemblies together in a computer using modern ultra-fast logic and you can calculate the history of the universe in 30 seconds. A hand calculator equivalent to every computer on Earth now working as one machine...
I can't believe that this computer expert is unaware that the first Apollo Landing had less computer power then today's wristwatch and I'm not talking about a smartwatch. It also landed completely manually it was not a computer Landing. Anyway I agree with his point that computers are completely involved in all of our space exploration today
This is remarkable. Being able to manipulate INDIVIDUAL Electrons and Photons to gain an exact outcome is profound. This steady-state construct is fast approaching the required results needed for Quantum Mechanical Devices. There is more space down the bottom, for Quantum particles exist below this threshold.
Okay so how can I do this? Tell me how to make a quantum computer small enough to fit into my purse. What kinds of things can it answer? Could it tell me when and where I can respawn?
Excellent presentation. Does Plasma have the same quantum property as Electron? If Plasma is another type of PARTICLE from an Atom then it should have the same Quantum property as Electron. ( I hope somebody ans this question).
Great, but during the abacus analogy I was hoping to hear how a (very) simple quantum computation would (in principle) work. There is apparently some confusion over the description of "0 and 1 at the same time" versa more accurate "any 0 and 1 combination which sum to the sphere surface value" that I don't pretend to follow.
A quantum of energy, such as in a particular Photon, Electron, Neutrino, and the like: is one thing; it's a string/amount/corpus/micro-totality, etc. You could conceive of these things as being wholes of constituent parts (even if for now it is easiest for you to conceptualize them as being theoretically divisible into parts, by a process like quantum cutting, like if you had a Neutrino Knife or something like it and you simply took a photon or an electron and you shaved it into slices (presumably after freezing it into a cuttable phase of its being. But, we don't possess the ability to do that, yet. Anyway, in the absence of cutting these things up their totality is stuck together such that as a 5% amount goes, so similarly does the remainder follow. Think of a gooey glob of something like jello. If one part of it starts to spill out of a crack in the bowl the rest must follow. Not the best metaphor but it beats spending years trying to perfect some equally conjectural set of an applied in an effort to conceptualize difficult propositions (that is likely to be proven incomplete in the future.) At least, in my opinion.
Excellent talk. However in showing the schrodiger equation he should have used the K=p^2/2m expression for kinetic energy. It would have much more strongly shown relation with classical expression.
Interesting lecture on Quantum computer but in 21st century before inventing Quantum computer we need to discover the behaviour of nucleus and electron Atoms and molecular. Atoms are more complicated and elegance than we ever imagine
If quantum and classical states were so easily demonstrated Schrodinger could have been proud instead of rejecting his equation, so even now the unitary evolution of the wave function fails to demonstrate how all the process in the universe permit Maldacena to conjecture that the whole universe is a quantum computing function, deterministic and error correcting.
It's entirely possible he actually has interesting things to say about quantum computing, but I'm not going to suffer through all the whining about young people to find out.
Excellent lecture. However, I think the explanation of double slit experiment using electrons is misleading. A classical wave passing through two slits forms the interference pattern instantaneously on the detector screen at a single moment, a single instant vs. a single electron produces a single spot on the detector screen at one instant. It takes many many electrons, possible spaced days apart, to produce interference bands of spots on the detector screens. This is not a single instant phenomenon. Therefore, IMHO, the analogy breaks. Not sure why the professor says that a single electron goes thru both slits. If a single electron had produced a interference pattern on the screen, I would buy the analogy to classical wave and accepted it went through both slits. It is possible I am missing something.
No you're not missing something and from a conceptual POV the lecture is terrible - containing elementary errors and misconceptions such as the one you've spotted - but it's no worse than is typical of physicists. It's a sad fact that, for historical and social reasons, the elements of mathematical physics and quantum foundations* necessary for a proper understanding of the theory just haven't been widely and fully absorbed by the physics community. No-one should be talking about wave-particle duality ("werewaves") or particles being in multiple places at once [/ going through both slits] or spooky action / nonlocality etc. in 2022 but here we are. * We now understand that quantum theory (as distinct from quantum mechanics) is an algebraic reformulation and generalisation of classical (Kolmogorovian) probability theory. There are many consequences of this for QM from a conceptual and interpretational POV but one fundamental one is that those 'mysterious' quantum "waves" clearly belong to the probability part rather than the mechanics part. Classical probability, and consequently classical mechanics, written in the same formalism has these "waves" (and superpositions) too!
@@Verlamian Thanks for the clarification, Paul. I am an Engineer by profession and science literate. I am a physics enthusiast but not a physicist myself. Some of these analogies that scientists use always bother me :) I hope they clarify how far to take those analogies.
@@Verlamian The "shut up and calculate" dogma, even though it produced a lot of technological commercial success from Applied QM, did a lot of disservice to the understanding of fundamentals of Quantum theories. Also the PR battle won by the Copenhagen interpretation of QM also blocked the progress. Luckily this is now chaging.
