The Quantum Mechanics (QM) is established branch of physics with about 100 years of history behind it and countless technological implementations. I want to state clearly at the beginning of this post that I am aware and appreciate enormous contribution of QM as well as Solid State Physics to development of truly innovative discrete (digital) technologies in optics (laser, LED, photo voltaic cells, etc.) and electronics (superconductivity, semiconductor components etc.).
I do not intend here to question efficacy of the theory of Quanta but rather aim to question narratives disseminated widely in media, academia, and in many scientific circuits, supposedly explaining foundations of the Quantum theory as closely related to reality of universe. I will attempt to address some more controversial, often characterized as surreal, aspects of theory of QM in context of intelligibility debate continuing on this blog.
The aim of the post is specifically to dispel some of more bizarre, metaphysical claims about supposed nature of reality, claims, some good willed, seemingly learned individuals with advanced degrees, make and promote (mostly) in the media apparently to educate and attract new generations to careers in scientific fields. I am afraid that the result, of such noble but misguided efforts of stretching (or breaking) the truth about science and replacing it by phantom mirages of cinematic shock and awe enhanced by ecstatic narratives, will likely be opposite than intended. Especially bothersome is persistent interpretation of Quantum theory as directly describing true existing reality of microcosm and from that inference of peculiar pseudo-scientific quasi-religious conclusions resembling revelations of some outcrop of Hindu philosophy.
No proof of reality of Quantum theory exists to date. Perhaps because QM theory was conceived by human mind relying on extremely scarce and hard to interpret data, often obtained through purely abstract conceptualization of events defying sense-perception, in contrast to other classical theories of physics that were much more data driven. Quantum theory is strict mathematical theory applying certain unusual concepts that challenge common comprehension only because they are purely mathematical and not adopted from our common sense perceptions.
One of those purely mathematical concepts, that may sound familiar but in fact is extremely exotic, is a concept of (elementary or not) particle. The single micro-particle, a mathematical object, according to QM suppose to have bizarre basic properties, like mass, charge, energy, translational momentum and angular momentum, spin etc., and other magnetic properties. All those may be sounding deceivably familiar but are far from it. In this context no wonder why even after many decades of theoretical development, QM theory is unsure about mathematical objects corresponding to physical observables that could be tested against experiment. In other words quantum scientists are unsure what physical quantities they actually measure in experiment.
In fact none of micro-particles such as electron, proton, photon, neutron not to mention zoo of more exotic animals (quarks, neutrinos, tau, muon etc.) were ever directly observed and all are more or less products of unintelligible narratives, figments of scientific imagination. Their mass, charge and size are all inferred supposedly from experiments dealing with trillions of such “particles” measured not as individual particles but as mass densities, charge densities, energy densities, mass fluxes (fluid flows), charge fluxes (currents), energy fluxes* (heat flows) etc., all creations of mathematical field theory which QM adopted.
Another curious assumption, borrowed from classical statistical mechanics, is that all particles are indistinguishable from each other. This assumption has important consequences. First, since individual particle is undistinguishable from one another, we cannot say anything about individual particle. We cannot observe it nor even conclude about its existence because we cannot distinguish for example this electron from that electron. There is no continuity of identity since there is no identity. Second, dealing with trillions of such particles at a time, we cannot uniquely distinguish single particle by its characteristics such as energy, momentum, charge, etc. since their characteristics are distributed according to specific distribution functions postulated in theory of Quanta.
Hence, we cannot say anything about single particle belonging to a set of particles but only about large sub-sets of particles. The fact is that only large subsets of particles (actually fluxes) can be measured with adequate reliability and accuracy and in the process, only properties of sets of particles, and not properties of individual particle, can be derived. This alone renders all so-called experimental proofs of existence of individual micro particles moot point since no proof has never been provided nor could ever be provided due to fundamental assumptions of QM itself that precludes such possibility.
Some Q&A may be helpful in grasping more unusual concepts of QM in context of its intelligibility.
- You say micro-particles do not exist. What about some who say they saw electrons or protons or molecules!
We could not “see” micro-particles even if they existed. Do the math. We humans, see only in narrow optical spectrum, and as deep as we can theoretically see into microcosm, with assistance, is to about 100,000 angstrom (A) resolution, an order of 0.01 mm (1A =10-10m) and somewhat better with best optical microscopes while supposed “size” of typical molecule is of order of fraction of A and supposed “size” of electron is orders of magnitude smaller than that. The absolute theoretical limit for “vision” of anything is about 20,000 A due to human eye’s visible spectrum wavelength limitation.
Note that, what we could supposedly “see” with electron devices (wrongly called microscopes) and x-ray devices (spectroscopes), which have much better resolutions, is synthetic image created via specific programmatic interpretation of the non-visual signal data converted into human interpretable image, not a picture of reality but pure conjecture of it. At microcosm scales we cannot see anything.
- What about wave-particle dualism. Is it real?
The wave-particle dualism is erroneously interpreted in popular scientific media presentations, and in surprisingly large number of academic courses, as mysterious transformation of individual particle into a wave and back depending what we do with it or how we look at it. None of this is true. This is just mathematical trick of using wave-type of mathematical description when it fits experimental data or particle-type mathematical description when it fits experimental data. When data does not fit theory, data is disregarded, theory persists, similarly to religious dogmas facing medieval inquiries into nature of universe. None of those descriptions (wave vs. particle) relate to individual particle anyway but rather to so-called “particle/momentum” fluxes.
But what this trick hides is dilution of concept of existence of the particle within Quanta framework. In addition to scraping identity of individual particle, concept of existence of particle is being obfuscated. One may think that existing object such a particle should take some limited, well-defined volume of space/time. Not exactly. The quanta theory plays with this common sense notion when convenient. No wonder that such theory is mostly unintelligible to us.
As a sort of replacement of notion of existence of individual particle, Erwin Schrödinger introduced strange wave-function which if squared would provide peculiar distribution function of possible locations of particle, and ways to calculate chances of being found there, instead of definitive location if particle “existed” in common sense meaning. This, wrongly fraised, “ potential existence” concept could be summarized as a case of missing particle which location can only be guessed with certain probability of success. Nothing’s mysterious, just a case of fundamental law of missing sneakers in messy room, we often experience, except sneakers are always located in lowest probability places and always in last place we look. I submit that, there is no split identity or potentiality or actuality of a particle (or a sneaker for that matter) since QM has already abandoned the basic notion of identity and notion of existence has been diluted for mathematical convenience. But even that is not correct interpretation of wavefunction and “probability wave “.
The wave function (square of it or modulus) of individual particle does not actually describe probable locations of individual particle within “cloud” of probability wave but rather probability of locating certain fraction of particles at given location cell out of a cloud of trillions of particles in continuous distributed motion within entire system at certain quantum energy levels.
Unfortunately, based on misunderstood probability wave concept, some proliferate bogus interpretations of reality of universe as being built on possibilities of existence that are being actualized into existence, supposedly when we focus, think or measure them. Again we do not measure individual particle but fluxes (of whatever) by methods of massive integration processes and by applying large perception pyramid and “commonly” accepted rules as I wrote in previous posts. That’s why physicist have to be trained young so they adopt, without questions, arbitrary concepts, interpretations and perceptions as rock solid foundations of knowledge while most of the concepts and scientific conclusions were product of agonizing tradeoffs and uneasy consensus in scientific community often against any sense of intelligibility.
There is no dualism of reality as far as we can tell, no proof either, but instead reality of dual description of processes we could not theorize about in consistent unified way. There is no potentiality of existence claims stemming from QM. We are dealing with mathematical concepts of fields and not material particles or elements of sense-perceived reality.
- What about uncertainty principle, how it relates to reality?
Quantum uncertainty principle, derived by Werner Heisenberg, is not a mystery of nature at all. It is stemming, not from experiment or nature but directly from assumption about mathematical functional space that have been chosen for development of QM. Namely Square Integrable Lebesgue-Hilbert (Unitary) Functional Space (SILHFS) w/ orthonormal base. In QM orthonormal base of Hermite polynomials was chosen.
Any mathematical functional space with characteristics of SILHFS would produce analog of “uncertainty principle” which simply declares that properties of elements in the functional space cannot be determined to arbitrary accuracy. The limit of accuracy is statistically determined as an asymptotic limit at arbitrarily high confidence level.
In case of quantum theory “uncertainty principle” says that event time and energy (momentum and location) of a particle cannot be determined to arbitrary accuracy since their product has limited value of h/2pi where h happens to be Planck’s constant. However, Heisenberg interpretation supposing change of state of particle by sole fact of its measurement as it is disseminated even in some Ivy League schools is simply baseless.
Again what we are dealing with large fluxes of particles not individual particles and problem of unwanted influence of act of measurement on outcome of experiment is not quantum problem or effect but it is centuries old issue, well described in manuals of experimentalists and in books on error analysis, as it was elegantly put by Richard von Mises in his famous book, “Probability, Statistics and Truth” 1957, particularly in his critique of Heisenberg uncertainty principle.
The uncertainty principle was never directly proved experimentally but it is readily used in QM calculations for convenience. As I mentioned before, inability to precisely determine location or property of the particle is not coming from Heisenberg uncertainty “principle “ but from fact that concept of identity has been abandoned and concept of existence has been diluted in QM.
- What is quanta and how it relates to reality?
In microcosm of QM, energy and momentum (translational and angular, and spin) can only assume discrete values. The theoretical necessity of quantization of energy levels (and momentum states) comes from fact that quantum wavefunction equation of Schrödinger and Dirac (wave equation) are of periodic (wavy) nature, imposing discrete, allowable values on Energy as a condition for existence of nontrivial solution.
The quanta is defined as amount of energy (momentum) that particle must acquire (or lose) in order to jump (or drop) onto next allowed energy level (momentum) in equilibrium state. For simplified example: State 0; E0=E1-Q; State 1; E1, State 2; E2=E1+Q; etc., where Q is quanta of energy E. The concept of quanta is purely mathematical and quantum, absent from classical mechanics, and seems to be supported by spectral analysis when applying quantum interpretive framework.
- What is mysterious quantum tunneling effect and how it relates to reality?
The proliferated tales about quantum tunneling effect tell us that a particle can mysteriously pass through a barrier like a ghost through a wall. None of it is obviously true. The confusion stems from inappropriate reading of specific solution to wave equation, which is incorrectly interpreted as allowing for finite probability of an event that micro particle may pass through the barrier. In fact we are not dealing here with common sense physical barrier but with electrostatic potential barrier an abstract concept.
The correctly stated problem involves large flux of particles, majority having similar, close to mean (average) energies, lower than barrier potential energy which most of the particles cannot overcome and as a result “bounce back”. However, some small fraction of particles has enough energy to overcome the barrier because particle energy is distributed according to Bose-Einstein distribution (for boson type of particle) or Fermi-Dirac distribution (for fermion type of particle) in equilibrium state and hence there are particles with energies far exceeding average energy of particles in the flux. That’s why in experiments, some fraction of particle flux “appear” on other side of the barrier only because they were able to “jump” over it. Nothing’s mysterious, no passing through barrier here, in this flagship quantum effect.
5a. What’s mystery of quantum entanglement? Or is there any?
Erwin Schrödinger, responding to Einstein claim that QM is incomplete, first introduced quantum entanglement concept while discussing famous Einstein-Podolski-Rosen (EPR) paradox. Quantum entanglement, according to academic textbooks, is an outcome of the quantum process where two micro particles at coherent quantum states are represented by one wavefunction, which cannot be decomposed or disentangled into two separate wavefunctions corresponding to individual particle quantum states.
Since entangled pair of particles is described by one wavefunction it exhibits certain common characteristic called “strong correlation of quantum states”, which roughly means that quantum state of one particle determines quantum state of the other particle when measured. The controversial EPR paradox relates to such a case when two particles entangled into coherent quantum states are separated by arbitrary distance and when particle quantum state is measured, the other one quantum state is somehow instantly determined by results of measurement of the first one.
This EPR theoretical result is all too often incorrectly interpreted and proliferated as a proof of possibility of transmission of information between two points in space instantaneously at speeds exceeding speed of light in apparent violation of special relativity theory. This myth even entered quasi-technological realm through unfounded assertions about its applicability to so-called quantum computers, hyper fast systems not restrained by computing speed limitations. These misguided projects embarrassingly involve respectable investors and established scientific institutions.
Unfortunately, proliferated in media and academia common interpretation of the EPR paradox is simply groundless. First, since the effect is claimed to be resulting from supposed preservation of correlation between two entangled quantum states (particles) separated by a distance, the assertion that event of measuring one particle cause change in other particle quantum state instantly via mysterious act of communication or how Einstein put it through “spooky action at a distance” is simply illogical. The problem is that correlation of quantum states does not imply causality especially when something’s suppose to happen instantly and therefore would be impossible to distinguish between cause and effect, ruling out possibility of serializing information and consequently preventing any type of communications.
There are many more problems with quantum entanglement in QM. As I mentioned before in this post, micro-particles are indistinguishable and they have no identity, which precludes even consideration of two different particles in quantum entanglement in QM since we would not know which is which and in which quantum state is which of two without measurement that supposedly destroys quantum state. In simple words there could be no entanglement defined in a way as described in QM.
Moreover, we are dealing not with individual particles but with large particle fluxes and fields, which would mean that we are dealing with billions of entangled particle pairs instead of well-determined single pair of quantum states. The reality of multitude of pairs of distributed quantum states is rendering application of simple quantum entanglement model moot.
Another issue is proliferated in academia assertion that entangled particles are uniquely represented by single (entangled) wavefunction. Such assertion is unfounded. The SILHFS on which QM is defined requires that every wavefunction is decomposable into some sets of wavefunction components, orthonormal base. defined within it. So wavefunction of the pair particles is not really entangled and could be represented as product of superimposition of two individual wavefunctions.
The fact is that quantum particle entanglement has not been directly proven experimentally at all. Moreover, experimental results, which observables relate to magnetic momentum fields (spin), rather than to particles, are heavily inferred from assumptions of QM rather from the data and therefore have been largely misinterpreted.
The most common example cited is a boson particle with spin 1 (photon) split into two particles (fermions) with spin oriented 180 degrees opposite to each other +½ , -½ . They supposedly are separated, say one sent to Moon, while preserving entangled quantum state. At this stage we obviously do not know which particle is which because they do not posses identity. The probability of earth located particle to have spin +½ is 50% and -½ is 50%. In order to learn which one of two particles is located on Earth we measure the one we have with us and when result is +½ the other located on the Moon supposedly instantly sets to -½. But if result on Earth is -½ the other particle on the Moon supposedly instantly sets +½.
How this could happen? How an act of measurement of one particle sets up quantum state of other particle in entanglement? How to truly understand Quantum entanglement?
No mystery here as well, it is very simple and obvious. Simply nothing happens, no setting up of no quantum state.
Let’ use again analogy of missing sneakers. If you are missing pair of sneakers, you do not know where they are, where is left one and where is right one. When or rather if you ever find right one in your messy room then in that instant remaining sneaker, maybe thousands of miles away at your ex place’s garbage dump, must be the left one. That’s all. That’s a pair of sneakers entanglement miracle. It is just logical exercise in binary setup based on assumption about logical complementarity. Moreover, even if so called “indeterminate” state of entangled particle existed, it cannot be distinguished from determined but “unknown” state since no measurement is possible to establish that, therefore sneakers analogy is appropriate.
Quantum entanglement is purely mathematical, unintelligible creation, and so far with no proven connection to reality.
- Is quanta and ocean of associated unusual concepts intelligible?
Definitely is not in its entirety as I tried to show with alternative narratives about more exotic claims. May be due to this ambiguity of interpretation, slew of complete misrepresentation of QM and free literary artisanship with its epic narratives, proliferated in media and some academic settings, seems to feed religious or neo-scholastic persuasions and in insidious way undermine true advances in human thought and perception of reality, that pushed technological civilization ahead.
The modern science, a revolutionary idea of intelligibility and cohesive, repeatable experimental methods, with all its shortcomings should be passed to new generations aware of its potential and limitations. Proliferating outrageous myths of science ultimately will not succeed in steering creative minds of young people toward pursuing scientific methods of learning about reality around us and in process, will fail in ultimate goal i.e. improving quality of human life here on earth. But instead would produce army of compliant, close minded, learned elite incapable of creative thought.
- Does Quantum theory describe reality of microcosm? May be but there is no proof of it. In fact there is no ultimate proof for most existing scientific theories, as I write on this blog, since humanity is still in developmental stage where grasp of objective reality is itself illusory.
*flux is a stream of particles or fields.