The Quantum Puzzle

CAN PHYSICS COMPUTE?

Is Quantum Computing Beyond Physics?

More exactly, do we know, can we know, enough physics for (full) quantum computing?

I have long suggested that the answer to this question was negative, and smirked at physicists sitting billions of universes on a pinhead, as if they had nothing better to do, the children they are. (Just as their Christian predecessors in the Middle Ages, their motives are not pure.)

Now an article in the American Mathematical Society Journal of May 2016 repeats (some) of the arguments I had in mind: The Quantum Computer Puzzle. Here are some of the arguments. One often hears that Quantum Computers are a done deal. Here is the explanation from Justin Trudeau, Canada’s Prime Minister, which reflects perfectly the official scientific conventional wisdom on the subject:  https://youtu.be/rRmv4uD2RQ4

(One wishes all our great leaders would be as knowledgeable… And I am not joking as I write this! Trudeau did engineering and ecological studies.)

... Supposing, Of Course, That One Can Isolate And Manipulate Qubits As One Does Normal Bits...

… Supposing, Of Course, That One Can Isolate And Manipulate Qubits As One Does Normal Bits…

Before some object that physicists are better qualified than mathematicians to talk about the Quantum, let me point towards someone who is perhaps the most qualified experimentalist in the world on the foundations of Quantum Physics. Serge Haroche is a French physicist who got the Nobel Prize for figuring out how to count photons without seeing them. It’s the most delicate Quantum Non-Demolition (QND) method I have heard of. It involved making the world’s most perfect mirrors. The punch line? Serge Haroche does not believe Quantum Computers are feasible. However Haroche does not suggest how he got there. The article in the AMS does make plenty of suggestions to that effect.

Let me hasten to add some form of Quantum Computing (or Quantum Simulation) called “annealing” is obviously feasible. D Wave, a Canadian company is selling such devices. In my view, Quantum Annealing is just the two slit experiment written large. Thus the counter-argument can be made that conventional computers can simulate annealing (and that has been the argument against D Wave’s machines).

Full Quantum Computing (also called  “Quantum Supremacy”) would be something completely different. Gil Kalai, a famous mathematician, and a specialist of Quantum Computing, is skeptical:

“Quantum computers are hypothetical devices, based on quantum physics, which would enable us to perform certain computations hundreds of orders of magnitude faster than digital computers. This feature is coined “quantum supremacy”, and one aspect or another of such quantum computational supremacy might be seen by experiments in the near future: by implementing quantum error-correction or by systems of noninteracting bosons or by exotic new phases of matter called anyons or by quantum annealing, or in various other ways…

A main reason for concern regarding the feasibility of quantum computers is that quantum systems are inherently noisy. We will describe an optimistic hypothesis regarding quantum noise that will allow quantum computing and a pessimistic hypothesis that won’t.”

Gil Katai rolls out a couple of theorems which suggest that Quantum Computing is very sensitive to noise (those are similar to finding out which slit a photon went through). Moreover, he uses a philosophical argument against Quantum Computing:

It is often claimed that quantum computers can perform certain computations that even a classical computer of the size of the entire universe cannot perform! Indeed it is useful to examine not only things that were previously impossible and that are now made possible by a new technology but also the improvement in terms of orders of magnitude for tasks that could have been achieved by the old technology.

Quantum computers represent enormous, unprecedented order-of-magnitude improvement of controlled physical phenomena as well as of algorithms. Nuclear weapons represent an improvement of 6–7 orders of magnitude over conventional ordnance: the first atomic bomb was a million times stronger than the most powerful (single) conventional bomb at the time. The telegraph could deliver a transatlantic message in a few seconds compared to the previous three-month period. This represents an (immense) improvement of 4–5 orders of magnitude. Memory and speed of computers were improved by 10–12 orders of magnitude over several decades. Breakthrough algorithms at the time of their discovery also represented practical improvements of no more than a few orders of magnitude. Yet implementing Boson Sampling with a hundred bosons represents more than a hundred orders of magnitude improvement compared to digital computers.

In other words, it unrealistic to expect such a, well, quantum jump…

“Boson Sampling” is a hypothetical, and simplest way, proposed to implement a Quantum Computer. (It is neither known if it could be made nor if it would be good enough for Quantum Computing[ yet it’s intensely studied nevertheless.)

***

Quantum Physics Is The Non-Local Engine Of Space, and Time Itself:

Here is Gil Kalai again:

“Locality, Space and Time

The decision between the optimistic and pessimistic hypotheses is, to a large extent, a question about modeling locality in quantum physics. Modeling natural quantum evolutions by quantum computers represents the important physical principle of “locality”: quantum interactions are limited to a few particles. The quantum circuit model enforces local rules on quantum evolutions and still allows the creation of very nonlocal quantum states.

This remains true for noisy quantum circuits under the optimistic hypothesis. The pessimistic hypothesis suggests that quantum supremacy is an artifact of incorrect modeling of locality. We expect modeling based on the pessimistic hypothesis, which relates the laws of the “noise” to the laws of the “signal”, to imply a strong form of locality for both. We can even propose that spacetime itself emerges from the absence of quantum fault tolerance. It is a familiar idea that since (noiseless) quantum systems are time reversible, time emerges from quantum noise (decoherence). However, also in the presence of noise, with quantum fault tolerance, every quantum evolution that can experimentally be created can be time-reversed, and, in fact, we can time-permute the sequence of unitary operators describing the evolution in an arbitrary way. It is therefore both quantum noise and the absence of quantum fault tolerance that enable an arrow of time.”

Just for future reference, let’s “note that with quantum computers one can emulate a quantum evolution on an arbitrary geometry. For example, a complicated quantum evolution representing the dynamics of a four-dimensional lattice model could be emulated on a one-dimensional chain of qubits.

This would be vastly different from today’s experimental quantum physics, and it is also in tension with insights from physics, where witnessing different geometries supporting the same physics is rare and important. Since a universal quantum computer allows the breaking of the connection between physics and geometry, it is noise and the absence of quantum fault tolerance that distinguish physical processes based on different geometries and enable geometry to emerge from the physics.”

***

I have proposed a theory which explains the preceding features, including the emergence of space. Let’s call it Sub Quantum Physics (SQP). The theory breaks a lot of sacred cows. Besides, it brings an obvious explanation for Dark Matter. If I am correct the Dark matter Puzzle is directly tied in with the Quantum Puzzle.

In any case, it is a delight to see in print part of what I have been severely criticized for saying for all too many decades… The gist of it all is that present day physics would be completely incomplete.

Patrice Ayme’

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20 Responses to “The Quantum Puzzle”

  1. Gmax Says:

    Awesome. Just awesome. So you are not the solitary weirdo out there anymore? What is this Massimo punk gonna say? You know the big time philosopher guy in New York who banished you for telling the truth about English philosophy?

    Let’s cut the chase. Could you give another overall description of your sub quantum mechanics?

    • Patrice Ayme Says:

      Thanks. Philosophers are paid for offering the blue, and red pills, as Brodix said.

      OK, I will give a synopsis of (some of) my theory… Have to find time, though…

  2. 1truegarcol Says:

    As progressive and informed as the pm of Canada is, he is not a physicist. Progress in QC is occurring; You seem to be emptying the baby with the bathwater.

    Research | 03 March 2005
    Quantum computing with realistically noisy devices

    In theory, quantum computers offer a means of… …conventional computers. Assuming that a quantum computer could be constructed,… …practice be required to function with noisy devices called ‘gates’. These… …cause decoherence of the fragile quantum states that are central to… …quantum…

    E. Knill

    Nature 434, 39–44

    Research | 21 April 2016 | Open
    Realistic noise-tolerant randomness amplification using finite number of devices

    …Randomness is a fundamental concept, with implications from security of modern… …to nearly ideal randomness using quantum-mechanical systems. However, so… …an unbounded number of different devices. Here we provide an… …a finite number of devices for amplifying arbitrary weak… …with…

    Fernando G. S. L. Brandão, Ravishankar Ramanathan[…]Hanna Wojewódka

    Nature Communications 7, 11345

    Research | 23 April 2013 | Open
    Topological quantum computing with a very noisy network and local error rates approaching one percent

    A scalable quantum computer could be built by… …The difficulty is that realistic quantum links are very error prone… …for cells to repeatedly communicate with each other and so purify… …topologically encoded data. Given a realistically noisy network (≥10% error…

    Naomi H. Nickerson, Ying Li & Simon C. Benjamin

    Nature Communications 4, 1756

    Reviews | 04 March 2010
    Quantum computers

    Quantum computing kit

    T. D. Ladd, F. Jelezko[…]J. L. O’Brien

    Nature 464, 45–53

    Research | 26 July 2013
    Complete tomography of a high-fidelity solid-state entangled spin–photon qubit pair

    Entanglement between stationary quantum memories and photonic qubits is… crucial for future quantum communication networks. Although high-… …parallel, scalable networks are most realistically conceivable, entanglement fidelities are… …scales unfavourably with the initial… …. With spin–…

    Kristiaan De Greve, Peter L. McMahon[…]Yoshihisa Yamamoto

    Nature Communications 4, 2228

    Research | 25 April 2010
    Quantum entanglement in photosynthetic light-harvesting complexes

    …complex, coupled, many-body quantum systems, in which electronic…

    Mohan Sarovar, Akihito Ishizaki[…]K. Birgitta Whaley

    Nature Physics 6, 462–467

    Research | 01 December 2005
    Creation of a six-atom ‘Schrödinger cat’ state

    …thanks to a paradox of quantum mechanics, in which a… …of many particles, as interactions with the environment destroy superposition in… …have extended the limits of quantum state engineering by creating the… …atomic systems to date. Working with atoms held in an ion… …quantum…

    D. Leibfried, E. Knill[…]D. J. Wineland

    Nature 438, 639–642

    • Gmax Says:

      The point Patrice made, I think, is that what Trudeau was saying, the credo of quantum computer folks, that one can compute with qubits like normal bits, is not proven. The guy in the Notices of the American MATHEMATICAL Society, MAY 2016 issue, is saying that theorems seem to stand in the way. He has a theorem saying errors scale linearly with size qubit pool

    • Patrice Ayme Says:

      Hi 1truegarcol. Thanks for the quotes, very nice. Wineland got the Nobel with Haroche, but Haroche’s work was more sci-fi… Entanglement/Nonlocality are the core of the Quantum.

      Trudeau told, very well, the basic idea.
      I also know that computations with a few qubits have been made with a variety of devices. I don’t thing they can compute 4 + 4 yet.

      And I know that D wave sells a (controversial) 12 million dollars “quantum computer”. This article to be published for the next issue of the AMS espouses, nevertheless, what has been (much of) my position for well over a decade or two. This is why I believe progress in physics will come from the quantum computer. It already does, from astronomy (as usual).

      I also believe that quantum simulating devices (basically interference devices) should be very useful. All I say is that a full mastery of a full quantum computer would require SUB QUANTUM PHYSICS. This essay in the AMS is the first article supporting that viewpoint I am aware of.

  3. brodix Says:

    Patrice,

    Yet what problem would you put this computer to solving?
    It is not as though nature isn’t its own computer and humanity along with it. Is there some question which will take raw computing power to solve?
    The fact is that the answer is whatever survives the process and human civilization seems to be on a path to self destruction. As Russell said of war, it doesn’t decide who is right, only who is left.
    Does it take a computer to figure this out and how to solve it, or is there some other problem?
    As I see it, the focus on computers is another process of deification. If you see it as an end in itself and not a tool to a further goal, then you make it a god.

    • Gmax Says:

      An example given in article is to compute much more of the Feynman expansion in QED. There is a whole science of what sort of problems a quantum computer would solve. Zillions of problems otherwise unsolvable

      • brodix Says:

        Gmax,

        It is not as though there are not a universe worth of complexities we could model and understand better.
        The question is whether this helps humanity to survive and thrive, or is it just more toys in the toy box.
        There is a bit of a Tower of Babel syndrome with all our advancing knowledge, in that as we all press forward with our particular goals and ambitions, what is there that holds us together? In earlier times people had a better understanding of how much they needed each other and they were likely far more self sufficient than most people today, but we, in our protected spaces, are fed this idea of the individual as master.
        Which is very useful for those in charge, as it validates their individual power, while keeping the larger society atomized.
        So are ever more powerful computers going to solve some of these elemental issues, or be used to enforce them.
        Say the NSA gets a quantum computer. What do you think it will be used for?

        • Patrice Ayme Says:

          NSA has probably a D Wave machine… Churchill ordered the British electronic computers destroyed in 1945: he did not want to let the secret out (Churchill also toyed with keeping in prison all French nuclear physicists who had launched the nuclear bomb program in 1938…). One electronic computer survived… And the French physicists did not rat out to Stalin (although some Americans did…)

        • Gmax Says:

          Fear knowledge not.

    • Patrice Ayme Says:

      War: we are left, so we were right.
      God: so we are.
      Quantum Computer: what we need for Artificial Soul.
      … And also a few other computations such as controlled H fusion… Making science into art…

      • Gmax Says:

        Artificial Soul? AS? Beyond AI?

      • brodix Says:

        Patrice,

        isn’t the real soul what pulses through the body and intelligence is the effect of it processing feedback?
        So we assume that if we process information, it will become conscious?
        Rivers and stream process information, as feedback from everything from gravity to obstacles. Wouldn’t that give them consciousness? No? That would be anthropomorphizing and deification. So why would a machine designed to read quantum state be conscious? Is it a tool, or a God?
        If I use a hammer to strike a nail, I am imbuing it with my own consciousness, as it becomes an extension of my hand, but truly manufacturing sentience and not just extending it, seems well beyond our current abilities.

        http://www.abc.net.au/news/2016-04-19/insects-may-have-evolved-consciousness-during-cambrian-period/7338032?site=science/news

        “Recent neuroimaging suggests insects are fully hardwired for both consciousness and egocentric behaviour, providing strong evidence that organisms from flies to fleas exhibit both.”

        It does seem to be something giving rise to intellectual complexity, not a product it.

        • brodix Says:

          http://gizmodo.com/how-do-plants-remember-things-from-one-year-to-the-next-1773090581

          “Misfolded proteins called prions—which lead to personality changes, dementia, and death in humans—may serve as a type of long-term memory in plants. That’s the fascinating possibility raised by a new study in the Proceedings of the National Academies of Sciences, which shows that a plant protein involved in responding to light and temperature may have shapeshifting, prion-like powers, allowing it to form environmental memories that can distinguish a single cold night from a shift in seasons.”

          Possibly we will start constructing computers out of biological material. Then we might have reason to worry about sentience and tools with attitude.

          • Patrice Ayme Says:

            Good find! I long argued that it is GEOMETRY which is inherited, and DNA is just one example (Prions, another). Prions are involved in the brain…
            The Quantum Computer is an approach to sentience (Artificial Sentience!). Going directly biological, another (say gluing neurons inside electronics). A variant is synthetic biology…

        • brodix Says:

          http://www.abc.net.au/news/2016-04-27/slime-mould-can-learn-even-without-brain/7363176?site=science/news

          “Key points:

          Slime mould is a single-celled organism
          The mould learnt to cross a bridge that contained unpleasant substances to obtain food
          The findings could provide clues as to when and where in the tree of life learning evolved”

          • Patrice Ayme Says:

            However modestly, the Quantum is intrinsically intelligent. That’s probably the most shocking part.

            • brodix Says:

              “Intelligent,” or “aware?”

              Consciousness effectively functions as energy, always seeking to expand, grow, escape, push the boundaries, seek out the most efficient route. Intelligence is the accumulation and storing the memory of this process.

  4. PM Trudeau’ s Satanic Philosophy | Patrice Ayme's Thoughts Says:

    […] no mistake: i would like to like Trudeau 100%, and I have spoken highly of him in the past (because Trudeau knows enough about the Quantum puzzle to sound intelligent on the subject). However Trudeau preaches to tolerate the intolerable, and that is […]

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