74 Matching Annotations
  1. Oct 2023
    1. If you look at George Ellis’s Google Scholar, it’s clear that he has gone down the deep end a while ago. What is it with these cosmologists? (Ahem, Penrose). Suddenly they discover quantum physics and it’s the solution to consciousness. Or gravity makes wavefunctions collapse.

      quote from Christoph Adami at https://twitter.com/ChristophAdami/status/1711583362647814485

      Re: George Ellis https://www.nature.com/articles/d41586-023-03061-y

      Physicists and quantum mechanics as solution to consciousness.

      See also: Physics in Mind: A Quantum View of the Brain by Werner R. Loewenstein

  2. Aug 2023
  3. Feb 2023
    1. | physics/mathematics | Classical Physics | Quantum Mechanics |<br /> |---|---|---|<br /> | State Space | fields satisfying equations of laws<br>- the state is given by a point in the space | vector in a complex vector space with a Hermitian inner product (wavefunctions) |<br /> | Observables | functions of fields<br>- usually differential equations with real-valued solutions | self-adjoint linear operators on the state space<br>- some confusion may result when operators don't commute; there are usually no simple (real-valued) numerical solutions |

    2. https://www.youtube.com/watch?v=5qGRPOzMWnA

      Watched the first 46:39 on 2023-02-02. His personal communication style is a bit off-putting, but remedied slightly by watching at 1.25 or 1.5x speed. He's broadly covering pieces directly from his text which seems much more compact and elegant. Questions from the viewers in real time is a bit muddy with respect to understanding what they're saying.

      I gave up on the video due to streaming issues.

    3. One of the problems in approaching quantum gravity is the choice for how to best represent it mathematically. Most of quantum mechanics is algebraic in nature but gravity has a geometry component which is important. (restatement)

      This is similar to the early 20th century problem of how to best represent quantum mechanics: as differential equations or using group theory/Lie algebras?

      This prompts the question: what other potential representations might also work?

      Could it be better understood/represented using Algebraic geometry or algebraic topology as perspectives?

      [handwritten notes from 2023-02-02]

    1. Bell’s theorem is aboutcorrelations (joint probabilities) of stochastic real variables and therefore doesnot apply to quantum theory, which neither describes stochastic motion nor usesreal-valued observables

      strong statement, what do people think about this? is it accepted by anyone or dismissed?

    1. Instead of trying to resolve in general this problem of how macroscopic clas-sical physics behavior emerges in a measurement process, one can adopt thefollowing two principles as providing a phenomenological description of whatwill happen, and these allow one to make precise statistical predictions usingquantum theory

      To resolve the measurement problem from quantum mechanics into the classical realm, one can use the observables principle and the Born rule.

    2. Principle (The Born rule). Given an observable O and two unit-norm states|ψ1〉 and |ψ2〉 that are eigenvectors of O with distinct eigenvalues λ1 and λ2O|ψ1〉 = λ1|ψ1〉, O|ψ2〉 = λ2|ψ2〉the complex linear combination statec1|ψ1〉 + c2|ψ2〉will not have a well-defined value for the observable O. If one attempts tomeasure this observable, one will get either λ1 or λ2, with probabilities|c21||c21| + |c22|and |c22||c21| + |c22|respectively.
    3. Principle (Observables). States for which the value of an observable can becharacterized by a well-defined number are the states that are eigenvectors forthe corresponding self-adjoint operator. The value of the observable in such astate will be a real number, the eigenvalue of the operator.

      What does he mean precisely by "principle"?

    4. Axiom (Dynamics). There is a distinguished quantum observable, the Hamil-tonian H. Time evolution of states |ψ(t)〉 ∈ H is given by the Schr ̈odingerequationi~ ddt |ψ(t)〉 = H|ψ(t)〉 (1.1)
    5. Axiom (States). The state of a quantum mechanical system is given by a non-zero vector in a complex vector space H with Hermitian inner product 〈·, ·〉.
    6. Axiom (Quantum observables). The observables of a quantum mechanical sys-tem are given by self-adjoint linear operators on H.
    7. Weyl’s insight that quantization of a classical system crucially involves un-derstanding the Lie groups that act on the classical phase space and the uni-tary representations of these groups
  4. Jan 2023
  5. Dec 2022
  6. Nov 2022
    1. Diseases don’t have to follow rules.

      Reminds me of something Carl Sagen said - I think it was Sagen though might have been Feynman - in the context of quantum physics, that the universe is under no obligation to observe our rules, or something like that.

  7. Oct 2022
  8. Sep 2022
    1. TLDR Hyperion is a moon orbiting Saturn and has chaotic motion about its CoM. This chaos is modeled correctly with classical mechanics but incorrectly with quantum mechanics. The catch being that if the average of all wavefunction collapses due to decoherence with interactions particles+photons is included then the prediction is correct. However, averaging is a non-physical process and, furthermore, collapsing a wavefunction requires instantaneous transfer of information which is nonphysical.

      • Saturn's moon, Hyperion, has chaotic motion due to the orientation of the moon about the orbit. Due to chaos, we can't predict orientation due to chaotic tumbling.
      • This can be described classicly with relativity.
      • Quantum Mechancis has been falsified because it fails to recreate or predict chaotic behaviors of the moon after 20 years.
      • Due to the linear nature of the eigenvector in Schrodinger's equation, it can not contain chaos.
      • By applying the correspondence principle, we only see chaos for up to the Ehrenfest time upon having the time function applied.
      • Physicists explain this incongruence in theories because the Schrodinger equation isn't including the entangled interactions of light/dust. These effects result in decoherence.
      • By averaging over the predictions we achieve the same solution as classical mechanics. Howevering averaging isn't a physical process. (e.g. rolling a 6 sided dice many times gives an average of 3.5 which is nonphysical)

      For a model to be real, we require that each individual prediction is true not the average. One solution is that Hyperion interacts and is having it's wavefunction updated nonlinearly resulting in decoherence. * Collapse of a wavefunction is said to not be physical due to instantaneous transfer of information being impossible. However, this wavefunction collapse due to interactions is required for the chaos of Hyperion to be modeled correctly. This is the issue.

  9. Aug 2022
    1. We finish with a com-parative analysis of these blockchain technologies,in terms of their relative vulnerability to quantumattacks.

      We expect a comparative analysis of various BCh technologies, in terms of their relative vulnerability to quantum attacks.

    2. he US National Institute of Standards andTechnology (NIST) has begun the process of stan-dardizing and deploying quantum-safe public-keycryptography

      This is an example of politics being biased by technology.

    3. Doing this, we can confidentlyconclude that by the year 2035 it is more likelythan not that quantum technology will have ad-vanced sufficiently to be able to break RSA2048efficiently. This conclusion is shared by well es-tablished researchers (see, e.g.[2, 3])

      Here, author uses other researcher's conclusions and states that by the year 2035 it is a fact that quantum technology will have advance sufficiently to be able to break RSA2048 efficiently.

    4. vulnerable toadvances in quantum technology

      the major threat: quantum technology

    1. Such optical modulation of atomic motion is an alternative path towards realizing 2D electronic states and will be a useful platform upon which novel phases in quantum materials may be discovered.
  10. Jul 2022
    1. i just wanted to interject that uh could i come at this point carlo i would like to insist a bit on this because i'm i'm not quite clear 01:07:22 on whether you are agreeing or not on the question of the mind um thank you this is also i wanted to ask him the same question mario uh so by just raise the question 01:07:40 specifically all right so let me okay since we're talking about nagarjuna now i would also like to uh read some simple verses that he has and get from both from barry and you what do you 01:07:53 think so this is from chapter three examination of the sentences seeing hearing smelling tasting touching and mind are the six sense faculties their 01:08:04 spheres are the visible objects etc like the scene the herd the smell that tasted and the touched the hair sound etc and consciousness should be understood so actually i'm confused from both of 01:08:18 you first of all barry is the mind anything special in buddhist philosophy or is it just like seeing and hearing and carlo are you saying there is anything 01:08:31 special about them right

      Mario interjects in the conversation to clarify Barry's question to Carlo, which is concerning the subjective aspect of experience and how it fits into science as the observer. It comes down the the question of existence of reality and the obrserver's role in that, epitomized in the question: If a tree falls in the forest, does anybody hear?

  11. Jun 2022
  12. Nov 2021
    1. Before we prove this lemma, we explain why such a lemma is useful for proofs in the quantumrandom oracle model.

      one-way-to-hiding lemma

    1. “Because physicists started out with the imaginary, unstable cube as their model instead of the real-world stable tetrahedron, they got into all these imaginary numbers and other complicated and completely unnecessary mathematics. It would be so much simpler if they started out with the tetrahedron, which is nature’s best structure, the simplest structural system in Universe.

      (Just as an aside, to remember later when you’re studying physics in school, I want to point out that the tetrahedron is also equivalent to the quantum unit of physics, and to the electron.)”

  13. Oct 2021
  14. Sep 2021
    1. His questioning of the scientific orthodoxy was the expression of a rare and maverick intelligence. He shows us that the nature of reality is infinite and believed in a “hidden” regime of reality – the Quantum Potential – that underlies all of creation and which will remain beyond scientific endeavor, an idea echoed by many mystical traditions.

      “We are all participants and observers in the emergence of a reality…the Observer is the Observed. Bohm shows us that we are all co-producers of a possible future in which personal and global transformation is possible.”

  15. Jul 2021
  16. arxiv.org arxiv.org
    1. a basic ingredient of quantum theory: the category Hilb whose objects are Hilbert spaces, usedto describe physicalsystems, and whose morphisms are linear operators, used to describephysicalprocesses

      [[hilb]] == [[hilbert spaces]] + [[linear operators]]

  17. May 2021
    1. Estimate of the equivalent classical computation time assuming 1M CPU cores for quantum supremacy circuits as a function of the number of qubits and number of cycles for the Schrödinger-Feynman algorithm. The star shows the estimated computation time for the largest experimental circuits.

      Informative diagram of Quantum Supremacy

    1. 2019                   Google claims to have reached quantum supremacy by performing a series of operations in 200 seconds that would take a supercomputer about 10,000 years to complete; IBM responds by suggesting it could take 2.5 days instead of 10,000 years, highlighting techniques a supercomputer may use to maximize computing speed

      1st quantum supremacy claim by Google, challenged by BM though.

    2. Lov Grover of Bell Laboratories invents the quantum database search algorithm

      Another useful quantum algorithm.

  18. Apr 2021
    1. After keeping brain organoids alive for several months, we finally observed the spontaneous emergence of brain oscillatory waves, similar to those detected by electroencephalograms (EEG).

      Is it related to Integrated Information Theory?

  19. Feb 2021
  20. Jan 2021
    1. New Quantum Algorithms Finally Crack Nonlinear Equations
      • We can’t predict the weather, among many other complex issues, because computers still can’t solve nonlinear equations.
      • But this might change soon, as two different research teams created algorithms that can be used for nonlinear modelling on quantum computers.
      • Their techniques still need refining, and won’t be real-world ready for years, but these studies are another stepping stone towards truly useful quantum algorithms.
  21. Oct 2020
    1. The graphs of ground state confinement energy againstsize (radius) for zinc sulfide nanoparticles in Figure 14 showthe dependence of confinement on the size of quantum dots.The result shows that ground state confinement energy is

      Las graficas de la energía de confinamiento en su estado fundamental en contra del tamaño (radio) por nanopartículas de sulfato de zinc en la Figura 14 muestran la dependencia de confinamiento en el tamaño de los puntos quánticos. El resultado muestra que el estado fundamental de energía en confinamiento es inversamente proporciona al tamaño (radio). Por lo tanto, cuando uno incrementa su radio (tamaño) la energía de confinamiento decrece pero nunca llega a cero. Eso es, el energía mas baja posible para el punto quántica de muestra no es cero. El confinamiento comienza cuando el radio del punto cuántico de muestra es comparable o del orden del radio exciton de Bohr.

    1. The notion that counting more shapes in the sky will reveal more details of the Big Bang is implied in a central principle of quantum physics known as “unitarity.” Unitarity dictates that the probabilities of all possible quantum states of the universe must add up to one, now and forever; thus, information, which is stored in quantum states, can never be lost — only scrambled. This means that all information about the birth of the cosmos remains encoded in its present state, and the more precisely cosmologists know the latter, the more they can learn about the former.
  22. Jul 2020
  23. Jun 2020
  24. May 2020
    1. quantum blockchain

      Do they really use a quantum blockchain? What exactly do they mean by that? Probably just a buzzword they're using to attract interest but aren't actually meaning literally.

    1. A quantum blockchain, the pair suggests, would take advantage of entanglement, which in most cases, applies to situations regarding space. But it could also be useful for situations involving time, such as blockchains. In such a blockchain, the pair explains, transaction records could be represented by pairs of entangled photons linked in chronological order. When transfers take place, photons would be created and absorbed by the hubs that comprise a network. But since entangled photons are linked across time, they can be caused to have never existed at the same time.
  25. Feb 2020
  26. Jan 2020
    1. ​=(α∣0⟩+β∣1⟩)(γ∣0⟩+δ∣1⟩)=αγ∣00⟩+αδ∣01⟩+βγ∣10⟩+βδ∣11⟩.​

      Might be the answer to an above inquiry.

    2. we apply a Hadamard gate

      What is the method to evaluate whether the output of a Hadamard gate should invert the bottom qubit or not?

      is (0 + 1) / sqrt 2 high or low?

      I'm missing something fundamental here.

    3. equal

      Frustrating wording here for me... Why is the word "equal" here at all. Doesn't seem to clarify anything.

    4. quantum teleportation

      I was thinking yesterday that "quantum" anything is both much more exciting and much less exciting than we've been led to believe by "Pop Science".

      It seems to boil down so far to some fancy linear algebra. I'm sure time will prove me a fool for thinking this, but just want to jot my thoughts down here.

    5. the

      For Computer Scientists, Microsoft put together a primer to Quantum Computing for us here: https://www.youtube.com/watch?v=F_Riqjdh2oM

      I could understand some of it (through 40m), but think this series of articles will help immensely and I'll return to it after.

    6. What does it mean for a matrix UUU to be unitary? It’s easiest to answer this question algebraically, where it simply means that U†U=IU^\dagger U = IU†U=I, that is, the adjoint of UUU, denoted U†U^\daggerU†, times UUU, is equal to the identity matrix. That adjoint is, recall, the complex transpose of UUU:

      Starting to get a little bit more into linear algebra / complex numbers. I'd like to see this happen more gradually as I haven't used any of this since college.

  27. Jul 2019
    1. unitary operator is a surjective bounded operator

      Why must unitary operator only be surjective? Why not bijective?

  28. Mar 2019
    1. Special Complexity Zoo Exhibit: Classes of Quantum States and Probability Distributions 24 classes and counting! A whole new phylum of the Complexity kingdom has recently been identified. This phylum consists of classes, not of problems or languages, but of quantum states and probability distributions. Well, actually, infinite families of states and distributions, one for each number of bits n. Admittedly, computer scientists have been talking about the complexity of sampling from probability distributions for years, but they haven't tended to organize those distributions into classes designated by inscrutable sequences of capital letters. This needs to change.
  29. Jan 2019
    1. The new experiment shows that, in a quantum world, two people can end up disagreeing about a seemingly irrefutable result, such as the outcome of a coin toss, suggesting something is amiss with the assumptions we make about quantum reality.
    2. Frauchiger and Renner came up with their thought experiment, which is an extension of something the physicist Eugene Wigner first dreamed up in the 1960s.
  30. Nov 2018
  31. Aug 2018
    1. Hegel believed that history culminated in an absolute moment - a moment in which a final, rational form of society and state became victorious.

      and probably not a bad outcome in an earlier era that thought of things in terms of clockwork and lacked the ideas of quantum theory and its attendant uncertainties.

  32. May 2018
  33. Apr 2018
    1. “We often discussed his notions on objective reality. I recall that during one walk Einstein suddenly stopped, turned to me and asked whether I really believed that the moon exists only when I look at it.”
  34. Mar 2018
  35. Feb 2018
  36. Dec 2015
    1. this week’s announcement by Google that a machine made by a Canadian company, D-Wave Systems, which is marketed as “the world’s first commercial quantum computer”, had shown spectacular speed gains over conventional computers. “For a specific, carefully crafted proof-of-concept problem,” Google’s Hartmut Neven reported, “we achieved a 100-million-fold speed-up.”
  37. Oct 2015
    1. the strongest evidence yet to support the most fundamental claims of the theory of quantum mechanics about the existence of an odd world formed by a fabric of subatomic particles, where matter does not take form until it is observed and time runs backward as well as forward.
  38. Feb 2014
    1. The mathematics of almost all eigenvalue problems encountered in wave physics is essentially the same, but the richest source of such problems is quantum mechanics, where the eigenvalues are the energies of stationary states ("levels"), rather than frequencies as in acoustics or optics, and the operator is the hamiltonian.