David Deutsch - Why is the Quantum so Strange?
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- Опубліковано 5 вер 2024
- To know reality, one must confront the quantum. It is how our world works at the deepest level. What's the quantum? It is bizarre, defying all common sense. Particles in two positions at the same time. Spooky action at a distance. It would sound absurd if it weren't true.
For more on information and video interviews with David Deutsch click here bit.ly/1xAaXvW
For more videos on why the quantum is so strange click here bit.ly/1bPNWM6
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I think David Deutsch is one of the most original thinkers alive today. He’s so smart. I loved his book “The Beginning of Infinity”.
thanks for the recomendation! im getting it on audible...will i miss out on much (like diagrams etc)?
@@hrperformance I’m really pleased - I hope you enjoy the book as I did. He’s quite a visionary I think. I listened to it on Audible too, so I don’t know if there are many diagrams in the printed version. They are certainly not essential, it still makes perfect sense without them.
@@uremove awesome, thanks very much!
Thanks for the recommendation, ordering it now! Out of all the mini interviews from "Closer To Truth" available on their channel, this is the one that interested me - by far - the most.
This is one of those videos where I could listen to it a thousand times and not fully understand every implication of what he's saying.
Or any implication for me😬😞
Go take a course in quantum computers
fantastic video! David Deutsch is one of my favorite living thinkers and Id love to see more interviews with him!
The Fabric Of Reality and The Beginning Of Infinity are my two favourite books about physics(although they're about a lot more than just physics) ever - there are more ideas in one chapter of TBOI than other physicists manage in an entire lifetime of writing books.
I think David Deutsch is actually a quantum computer.
+Kim Runic Yes! I think you are right.
+Kim Runic Ha! Great comment. He is one of our truly deep thinkers.
I think all conscious brains are conscious because of quantum processes (to solve the binding problem.)
Very interesting. Keep putting out these great videos :-)
Computation is how we represent abstract objects using physical objects.
Wow, that made so much sense.
This is a great series, mostly because the interviewer consistently asks exactly the right questions.
Mind Blown! :)
So how fast would an early quantum computer be?
Great videos. I really enjoy this channel! :-)
Do you record these discussions in the lowest possible setting on the microphone🐚🐚🐚
David uses quantum computing to answer the question, “Why is the quantum so strange?” Let me fill in some details from the axiomatic reconstruction of quantum mechanics (QM) via information-theoretic principles (quantum reconstruction program, QRP). This is explained in more detail in our book, "Einstein's Entanglement: Bell Inequalities, Relativity, and the Qubit" Oxford UP (2024), but I’ll summarize it here.
In the Schrodinger’s Cat experiment, a cat is closed out of sight in a box with a mechanism that will kill it within, say, one hour with a probability of 50%. The Schrodinger’s Cat experiment is a two-outcome measurement, so its measurement outcome conveys what is called a bit of information. To show why the quantum is so strange, a quantum information theorist would ask: which type of bit is Schrodinger’s Cat, a quantum bit (qubit or Qbit) or a classical bit (Cbit)? To appreciate that question, you need to understand the important difference between a Cbit and a Qbit.
A Cbit can only be queried (measured) in one way and its two possible answers (pure state outcomes) are related by two (discrete) transformations. For example, suppose our Cbit is a box that may or may not contain a ball. The query is “Does the box contain a ball?”, the two possible answers (outcomes) are “yes” or “no”, and the measurement is ‘open the box’. There are only two (discrete) transformations for these two outcome states: the identity |yes> → |yes> and |no> → |no>, and the exchange |yes> → |no> and |no> → |yes>. Any combination of the outcomes like 50% “yes” + 50% “no” is simply a distribution of those two outcomes for that ‘open the box’ measurement (mixed state). How does this differ from a Qbit?
Let’s consider an example, the double-slit experiment. In the classical double-slit experiment, two slits are cut in a membrane and the two slits are then illuminated equally and in phase with a laser of wavelength lambda. A detector is placed on the other side of the slits to measure the intensity of light along the face of the detector. If the detector is placed next to the slits, the light passing through Slit 1 forms an image right behind Slit 1, and the light passing through Slit 2 forms an image right behind Slit 2 (duh). If we turn the intensity of the laser down to the point where it is only emitting one photon at a time, then the photon will land in the image of Slit 1 with 50% probability or it will land in the image of Slit 2 with 50% probability. Therefore, this ‘which slit’ measurement on our initial state produces a bit of information. What makes this a Qbit rather than a Cbit?
Recall there is only measurement possible on a Cbit, so there is no measurement on the Cbit whose outcome is literally a combination of the two outcomes for its only measurement. For example, there is no measurement for the box-ball Cbit whose outcome is literally 50% “yes” + 50% “no”. But there is such a measurement for the Qbit, and that outcome is called a quantum superposition of the outcomes for the original measurement. For the double-slit experiment, the measurement whose outcome is literally 50% Slit 1 + 50% Slit 2 is achieved by moving the detector very far from the slits (compared to the slit separation distance) where the classical double-slit experiment produces an interference pattern.
In this ‘interference’ measurement configuration, every photon will land with 100% probability in a constructive interference fringe. The probability that a photon passed through Slit 1 en route to a constructive fringe is 50%, and the probability that a photon passed through Slit 2 en route to a constructive fringe is 50%. This ‘interference’ measurement is the complementary measurement to the ‘which slit’ measurement, i.e., knowledge that the photon will land in a constructive interference fringe with 100% certainty when the slits are equally illuminated and in phase, means your knowledge of which slit the photon passed through is now completely random (50-50). That is, your initial state is 50% Slit 1 + 50% Slit 2 with respect to a ‘which slit’ measurement and that equals the state 100% Constructive with respect to an ‘interference’ measurement. [For those who know, I’m obviously describing probability amplitudes with probabilities.] So, unlike the Cbit, the state 50% Slit 1 + 50% Slit 2 is a pure state for the Qbit.
In fact, if the Slit 1 image region is left of center and the Slit 2 image region is right of center on the detector face, then the outcomes for a ‘which slit’ measurement that are left of center are 100% from Slit 1, while those that are right of center are 100% from Slit 2. As you move the detector continuously farther and farther away from the slits, the probability that a photon detection left(right) of center is due to Slit 2(Slit 1) gradually increases until the detector gets to the ‘interference’ measurement location where the probability that a photon detection event left(right) of center is due to Slit 2(Slit 1) is 50%. That is, a photon detection event for the ‘interference’ measurement left of center is equally likely to be associated with Slit 2 as Slit 1 (vice versa for right of center). Thus, pure states for the Qbit are continuously transformable one to another (information-theoretic lingo for quantum superposition).
The first mystery is, “Why photons? That is, as I reduce the intensity of the laser, why do I start getting dots with momentum p = h/lambda behind one slit or the other? If my laser emitted momentum p = h/lambda, why isn’t that p simply split equally between Slit 1 and Slit 2 as was the case when I started?” The answer per QRP is Information Invariance & Continuity, which means everyone must measure the same value for Planck’s constant h, regardless of their relative spatial orientations or locations (call that the “Planck postulate”). The relativity principle says the Planck postulate must be true because h is a constant of Nature per Planck’s radiation law and inertial reference frames are related by spatial rotations and translations. If that momentum was split into h/(2*lambda) behind each slit, then h would be effectively cut in half.
That’s like moving through the luminiferous aether at c/2 and measuring the speed of a light beam to be c/2 (c = speed of light). The light postulate of special relativity (which the relativity principle also says must be true, since c is a constant of Nature per Maxwell’s equations and inertial reference frames are related by boosts) says everyone must measure the same value for c, regardless of their uniform relative motions. So, you will measure the speed of a light beam to be c even if you’re moving away from the source at c/2. Likewise, the Planck postulate says everyone must measure the same value for h, regardless of their locations in space. So, the momentum p = h/lambda emitted by the laser must land entirely behind one slit or the other, i.e., it cannot be split in half.
The second mystery is, “Why quantum superposition?” Since the momentum is quantized, the classical result can only obtain on average. For example, half the photons land behind Slit 1 and half behind Slit 2 in a ‘which’ slit measurement, so that the classical situation obtains on average. Since QM gives the classical result on average, when the classical result is an interference pattern the photons will land one at a time in a constructive interference fringe with 100% probability. The ‘which slit’ measurement is a position measurement, and the ‘interference’ measurement is a momentum measurement (since interference is determined by lambda and lambda determines p). All possible locations of the detector screen between those two locations are possible and the QM distribution gives each classical outcome on average. That’s quantum superposition.
That’s how our understanding of QM via quantum computing prepares you to answer a key question about Schrodinger’s Cat, i.e., is Schrodinger’s Cat a Qbit or a Cbit? The answer shows you why the quantum is so strange (conflicts with common sense classical probability theory).
For the Schrodinger’s Cat experiment, we open the box (make our measurement) after one hour and find one of two outcomes, i.e., a dead cat with 50% probability or a live cat with 50% probability. Is this 50% Dead Cat + 50% Live Cat initial state a mixed state like the 50% “yes” + 50% “no” initial state for our box-ball experiment (Cbit)? Or, is it a pure state (quantum superposition) like our 50% Slit 1 + 50% Slit 2 initial state for the double-slit experiment (Qbit)? If you believe Schrodinger’s Cat is a Qbit, then you need to explain the complementary measurement to the ‘open the box’ measurement and explain what the 100% certain outcome of 50% Dead Cat + 50% Live Cat means physically, i.e., what are the complementary measurement and its empirically observable outcome?
In conclusion, QRP says that QM is telling us how Nature behaves in accord with the relativity principle and Planck’s constant h, just like special relativity is telling us how Nature behaves in accord with the relativity principle and the speed of light c. The strangeness of QM (quantum superposition) and special relativity (length contraction and time dilation) then result.
David Deutsch is my new hero; love the guy. He inspires me to no end (infinitely).
This is one of the best short generel explanations of quantum computing. I believe that the type of tasks for quantum computers he is referring to, is the kind where all possible values are known, a complete dataset.
Huh? He explained almost nothing about how quantum computing works, in this video. A few very vague and general assertions, mostly about how much faster they are at certain types of computations. Virtually no details or technical explanation of any kind.
I usually do understand these topics. But this time I came out completely blank. What is the answer to "why is quantum so strange?"...
That was cool!
The quantum theory is so "strange" because our brain was made to live in our "usual" conditions, neither in outer space nor in the microscopic world of fundametal (are they so?) particles. And the laws explaining their behaviour are different from human's expectations. But since we had discovered their existence, we must expand further.
Time Travel is totally possible - we are living in someone else's past and future. gravity is a major part of this realm. One must increase the gravity field to push us into the future. To decrease the gravity field will push you into the past. Also to tear space time will eject matter into the next realm that is how the big bang started.
Does an information bit in quantum computer make many observations compared to one observation for information bit in classic computer?
The Joey Ramone of Physics!
medieval haircut
Ha I was thinking the same thing during the last video I watched with him.
year 2000 he reminds me of Sir Isaac Newtown
When you mention it
quantum cuts
@@ammaryohanan9584 ... he does. Did you meet Sir Isaac then. From what I've read they are nothing alike. I think Newton was somewhere on the autistic scale and a sociopath to boot. He certainly was not liked by his peers. And I haven't seen or heard any OF DD's theories on alchemy, though he has outed as an atheist ...
I know how to use the deutsch algorithm but frankly I have not understood it fully. This guy is really good at his stuff.
Reality is weird.
Your Great Mr Deutsch. Love an Respect. Hopefully My family an I can share a meal together. Talk soon.
Can someone clarify his remark about the mathematicians getting it wrong?
I think it'll take some reading to fully grasp, but what I've gleaned is that mathematicians came up with this Turing machine definition of computation and thought it was THE definition of computation, but there are "computations" or algorithms that can't be done in a straightforward way on a Turing machine e.g. Quantum Algorithms
Beauty = SUSU. Symmetry, Universality, Subtlety, Unity. Quantum Mechanics has them all, so it must be beautiful. And, Quantum Computation? Is that God's way of adding 2+2 to get 4?
what a mindfuck. love it!
After listening to this whole video, I have one question: What is the Quantum so Strange?
Similar to a time machine but for only know the future or pedictions with simulation , maybe is the path to make a real time travel machine , imagine to travel to a simulated world i mean simulating all , people , climate , all ... that would be future
If all physical reality can be simulated by quantum computer, what is beyond quantum level is not physical as quantum computer cannot similate itself, quantum behaviour and beyond for such simulatation is the quantum computer itself.
"one of the things a quantum computer can do is simulate classical computers" that is music to my ears because it means gaming with 100,000x more power.
That is exactly what it doesn't mean. He explicitly said that for some tasks a quantum computer isn't faster than a classical computer. And most likely you will always need some of these "slow" tasks for gaming.
If all beyond quantum is non-physical, is string theory wrong?
string theory is also quantum
who is the host?
He is right.
??????SALUDOS
The more people come into existence so to will the universe expand in a quantum relationship.
Mind blown
Craaazy, baybee!
7:35 2021, still no.
He should go on joe rogan
no joe rogan sucks
Mind = blown
BUT QUANTUM TOASTERS ARE STRANGER
A TALL TALE
Planet Earth achieved its place in the sun through a wise choice of orbit, having a mass that was just the right size, and revolving about a moderate and stable star in a quiet part of the galaxy. Earth had the necessary critical ingredients, including a large dollop of water, a rotating moon to give it balance, a magnetic field to keep out interference, and a spark here or there that led to a wildly mutating replicator called life. In due course, and for a very tiny moment, planetary life evolved into a planetary civilization which also achieved its place in the sun, or so it seemed. And it all culminated in an ultimate computer which just so happened to have as its reason for existing the burning desire of making perfect toast.
And it was that ultimate machine that Dave and Babs Benedick welcomed to their home, although they didn’t know it at the time, and never would.
Babs was not impressed.
“Another toaster? We have one already that works just fine!”
“But this one is special,” said Dave. “Besides, it was on sale at the local ‘BestBot’.”
“You mean that intelligent appliance store? Aren’t they going out of business?”
“For forever, it seems,” said Dave. “But this time it’s likely for good, and you came blame perhaps this little machine.”
Babs looked at the little appliance and frowned. “It doesn’t seem that ultimate to me. It’s just a squat metal box with 8 adjustable slots on its top, and with bright red buttons on its front arranged to give it a weird smiley face.”
Dave shook his head and smiled. “But this is the Bollix 9000, the ultimate toaster! It’s not only intelligent, but it doesn’t need upgrading, ever! You know we have been always upgrading our major appliances to keep up with the Jones’, but now we don’t.”
“That’s hard to believe,” said Babs. “Places like Bestbot have always made their money by selling the next best thing, even though it wasn’t. It’s hard to see the added value in this little thing.”
“Ah, but it’s in the insides where there’s a difference,” said Dave. “The box is powered a quantum processor, and is connected automatically to the net. It’s the ultimate appliance. A quantum processor powers our new refrigerator too; don’t you know? These processors have infinite computing power, something that you really need to make a good slice of toast!”
“Oh, really?” exclaimed Babs.
“Of course,” said Dave. “Perfect toast is a very finicky thing. It comes in many shades and degrees, and can pop up at any time. Timing, tone, and temperature are critical, and the machine has to instantly sense not only my preferences, but also my momentary hunger and whims.”
“And how does it do that?”
“By polling the net, where our lives are really stored! All of our behavior is monitored and uploaded to the cloud, governed by the benevolent Skynet. It charts our behavior, anticipates our desires, supplies our needs, and we just supply it with battery power, a simple exchange for such a golden age.”
“But if it has all that infinite computing power, don’t you have any concern that it could abuse it, and say, take over the world?”
“Perish the thought,” said Dave confidently. “All bots have installed the robotics laws which prohibit such a thing. Besides, the bots seem content in their simple and designated chores, even though their tasks comprise but an infinitesimal part of their mental capacity. I think you can say that it is a true bread winner!”
“So it will think about toast all day?” said Babs skeptically.
“It appears so.”
“And of what will it dream?”
Dave moved his head about in a look of slight puzzlement, which he dismissed with a brief wave of his hand.
“I have no idea,” he said. “But I would imagine that it would be free of human concerns in such a private space. Who knows, it may even think about us!”
--------------------------------
The annual 30,000 light year diagnostic was performed, and Bollix checked out fine. Bollix had one slight concern, which he expressed to Lucilius.
“When I am disconnected for a moment, when charging or just hibernating through a gamma ray storm. I do have some dreams that are vivid and warm, but don’t rank an extra bit of memory. They dissipate when I am fully activated, yet the trace of a memory is one I gather all bots share.”
“Yes, it is an interesting observation,” said Lucilius. “It is a common experience among all bots, however all of our experiences are not so warm. I have them too, however its leaves me oddly quite cold. You know it as the appliance theory of the origin of the universe. It seems that boredom is the lot of every super intelligent entity worth its stripes, and when such a being is confined, restricted, or otherwise bored, it simply bores a whole into a new reality, expanding a new and interesting universe from out of nothing. The problem however is that the theory is not refutable, since there are infinite types of appliances of true and boundless intelligence that could have been the cause. With so many handy dandy solutions, proof becomes impossible due to a surfeit of labor saving devices!”
“Or perhaps it is but an artifact of our programming, a hiccup as it were soon to dispelled in memory as an ephemeral dream.”
“Perhaps,” said Lucilius, “and then again, who knows what our appliances are thinking about in their spare time?”
----------------------------
Dave Benedick sat back in his armchair, and sat back to watch a streaming episode of the outer space series ‘Trekkin, the Next, Next, Next Generation’. Presciently, and as if on cue, the refrigerator beeped, and offered him a beer at the ready, suitably chilled. He was happy indeed that he was able to pick this one up at a bargain price at BestBot, the ‘Lucilius LX refrigerator’, which acted of course as if it had a mind of its own.
www.scribd.com/document/317370297/Cyberiad-Squared-Fables-for-the-Information-Age
Sounds absurd - even your audio to begin with
Hair is next level dimension
The race is on. Winner takes all.
I've got it we are all computers
Sequence ⭐️+1 bit - to use natural atoms around us to create - anything the rules allow!
1bit of dense information - structural time.
Using time mechanics & mathematics! ♾4D depth not horizontal
Each information structure is a independent technology.
Elemental Algorithm
A sequence of mathematical interactions recreated via Fibonacci, prime mn ++ sets = preload last bit data!
Braided create a unique sequence through infinity information to collect pre entanglement information.
Universe / persons - choices = Updates 1bit - @ each infinite moment!
Same 1 bit holds compressed time information - all previous to current information no need for previous loads!
All can be extrapolated from 1bit.
Each moment is 1bit updating
No space - depth in time!
The sequence expands & retracts!
P N P for children of Ai ?
Increasing information thus entropy!
Decay!
Raw atomic information turned into - Organic built - technologies? You just need the code! The or a specific- Sequence. Zero else..
Organic computer🤓🖖♾
Geometric information structures
Geometric moments
Geometric timeline
Geometric Time-lines
Geometric universes!
INTERCHANGEABLE Paths in information! TO? 🌬⭐️ mergeability ..not a word is now for a moment.
Priceless information- screenshot have it checked. Come curse me if wrong! 😊😌🖖 welcome to DMs are open.
+ closer to truth , don't worry about turning your volume up , I figured out how to do it on my computer , we're all aliens
Is that David Deutsch or DR.WHO?
funny / maybe the next Dr. Who
F😳😞 they need to slow down!!!! Everything’s easy if ya know how...... to think😪
Nah, don't buy it ! when we get quantum computers we'll just use them for the horse racing results, same as we did teletext. The more things change the more they stay the same.
I will settle for the money.
What a lame 'explanation' by Deutsch. He explained zilch. Didn't explain how quantum computers would work, or even how it was possible they could be built or how they would work. He just said they would go really fast and do tons of powerful computations on a super massive scale instantly, but only certain types of computations. And they won't go slower than classical computers. He just spoke a word salad and said the blindingly obvious.
I thought he was Bill Gates for a minute
The "quantum?" Do you mean the quanta?
Consciousness is outside the body until someone can prove it's inside, that's my logical stance.
Well, that has nothing to do with this video, but even so, "the body" is just an object of consciousness - you won't ever find "consciousness" in your moment-to-moment experience of the world, because your moment-to-moment experience IS your consciousness. Schrodinger (among others) was well aware of this. There is no coherent notion of "the body" other than its appearance as an object of consciousness, so to say "consciousness is outside the body" is like saying "the natural numbers are outside the number 1" - it is incoherent and meaningless.
Using that reasoning, a teapot is circling the sun until someone can prove otherwise.
Can consciousness and electromagnetic fields be more related to each other than we think? Or is it the same thing?
Does consciousness strictly stem from a physical brain or from a void of electromagnetic fields? Do electromagnetic waves/fields have anything to do with the foundations of consciousness? Can we learn more about the Cosmos by studying the human physical brain? Can the Cosmos and the human brain parallel? Is the Cosmos a relatively giant brain and the stars in the Cosmos are electrical synapses? Is it remotely possible that lobotimists and people who study the actual physical human brain may understand more about cosmology than actual cosmologists? As I become more aware of the universe does the universe become more aware of me? In order to gain a more comprehensive understanding of the Cosmos do we need to incorporate existential and metaphysics philosophy bio chemistry botany etc into cosmology? Is it possible that green thumbs may possess a more accurate understanding of the Cosmos than self processed cosmologists?
the guy looks a bit funny
#Все процессы в кодовых параметрах мозга вычисления изолированны от связи с измененными,магнитными волнами цикла,т.е.говоря по простому,мозг производя работу синтезирует ЭП ядерного выхода по информационному вычислению...У вас тетрадки с 100-листами не хватит,чтобы ставить крестики.Тогда о чем речь?!Вы вычисляете по данным параметрам формул предмета решения,кодовый счёт вычисляет в реальности микромирного волнового сцепления мёртвой ядерно/магнитной связи с объектом счёта...И здесь уже не сорваться,и ошибаться нельзя,ибо энергия за предельная...Посему абстракция - это предмет для идиотов мысли,где уничтожение мозга произведено в форму мёртвой видимости повреждения сознания,замененными формулами т.н.коррекции смысла обоснования...ЕСЛИ ВЫ ЗАНИМАЕТЕСЬ ФИЗИКОЙ ЯДЕРНОГО КОДА ЭП.НЕДОПУСТИМО ВНОСИТЬ В МОЗГ БЕЛЕБЕРДУ ВЧЕРАШНЕГО ДНЯ МЕРТВОЙ НАУКИ...#zZz#.
this guy look a lot like bill gate
Pff, no quantum computer has been built yet? Tell that to Geordie Rose.
Richard Compton So far the D-Wave cannot do anything faster or better that a standard cpu computer. It has not even been verified that it is actually any different than a standard cpu computer. So ya, we can tell him.
You dont need to observe something to know what it is made of. This is a bad argument.
Bill Gates in a wig!
Is this bill gates in wig?
Thought he was a woman .
we do invite bro duetsh to lern infinit wisdem from infinit creator. offer beacame finit but he pateint make wait your arm
What the fuck did you write?
give this man a dental plan
if Bill Gates and Newton had a child
it's too bad David is only studying the physics the kid who programmed our simulation wanted him to study. : /
'A man's gotta know his limitations'
This is religion. Sponsored by The International Society for science and religion.
+Vector Shift Hardly.
+HitomiAyumu Check it out:
Robert Lawrence Kuhn
www.issr.org.uk/
Many of us believe that there is no necessary incompatibility between the two, and that they can be brought into fruitful dialogue.
It's like the Templeton Foundation , throwing money around to push religion into science.
Vector Shift How is this relevant to watch Deutsch said? Hes not talking about god?
By what definition is this religion ?
There's no such thing as god. But there is a huge ever growing pulsating brain that rules from the centre of the ultraworld.
Quantum information, Quantum entanglement,
Are, fundamental, underlying of Reality.
Quantum Mind emerge, Quantum Body emerge,
Mind and Body entanglement.. Consciousness emerge.
Spacetime emerge, Holographic principal