Dear All,
Recently, my manuscript “Quantum register cannot be real” was rejected
in the third journal. But this time the editors made the decision not
just on the basis of their belief in what the majority believes, but
on the basis of the Reviewer's comments, see below. Comments written
by a professional allow us to understand the reason for the mass
delusion about quantum mechanics, and in particular Bell's
inequalities. The Reviewer understand that a quantum computer can be
possible only according to a purely instrumentalist view, but he, in
contrast David Deutsch, “The Father of Quantum Computing” (see
https://www.wired.com/2007/02/the-father-of-quantum-computing/?currentPage=all
), does not understand that a real device, for example an interstellar
spaceship, can be made on a theory explaining experimental results
rather than a theory which only predicts the outcomes of experiments,
see below my reply to Reviewers' comments.
Most scientists, as naive realists, never understood that Heisenberg,
Bohr and other creators of quantum mechanics followed an
instrumentalist point of view. Karl Popper wrote more than sixty years
ago: “Very few physicists who now recognize the instrumentalist point
of view of Cardinal Bellarmino and Bishop Berkeley realize that they
accept some philosophical theory. They also do not realize that they
are breaking with the Galilean tradition”.
The Reviewer realizes that he follows the instrumentalist view. But he
does not understand that the instrumentalist view is misleading. This
point of view has misled in particular Richard Feynman, Yuri Manin and
all authors of publications about quantum computing who have not
understood that the exponential increasing of the complexity of
computing with the number of elements of quantum systems takes place
not because the system is quantum, but because the probability of
observation is calculated, see Conclusion of my manuscript. It is
impossible to distinguish the mathematical description of the results
of observing spin projections from the results of observing
Schrodinger's cats, according to a purely instrumentalist view. I
should also note that debate about Bell's inequalities do not make
sense according to this point of view.
With best wishes,
Alexey
Reviewers' comments:
Reviewer #1: The author of this paper claims that a quantum register,
or a qubit, cannot be real and so cannot exist. If I understand
correctly the author's final arguments, this also means that quantum
computing will never work. WIth the words of the author, it will
actually be one of the biggest mass delusions of modern science. In
practical terms I assume therefore that the author believes that
so-called quantum supremacy will never be reached.
I personally agree on several points discussed in this paper, in
particular on the historical discussion on the various points of view
about the fundamentals of quantum mechanics. I agree with the author
that the point of view of Bell has often been misled. I can even agree
on some sociological considerations in Section 8, although I believe
these should not be part of an article to be published on a physics
journal. In general, I agree with the authors that quantum mechanics
is not a fully satisfactory theory (in particular I think that the
problem of measurement is not fully solved, as the majority believes)
However, I'm failing to see any new insight or solution proposed by
the author in this paper. The main "claim" of the paper is actually
that a qubit cannot be "real", based on the assumption that to be real
it must exist in real space. I cannot get this point, to me it looks
quite a captious argument. Everyone using quantum mechanics does
calculations in the Hilbert space, and apparently it works. I don't
see why this is a problem. It seems also that in quantum mechanics you
really need complex numbers: are complex numbers real? Should we care
about the reality of complex numbers? So, is Hilbert space real or
not? This is not relevant as long as calculations work. This is the
essence of instrumentalism, you don't ask questions like "what is
real" but you simply stick to the predictions you can do. The majority
of physicists working in quantum mechanics are instrumentalists, which
doesn't mean being unable to see that, at a deeper level, there are
still fundamental issues in quantum mechanics that we may hope to
solve in future.
In a purely instrumentalist view (limited to mere experimental facts),
existing experiments are apparently supporting the view that quantum
computers not only can be built, but actually work as they are
supposed to work. One has to accept this as a fact, or demonstrate
that these works are flawed. But one cannot refute these claims on the
basis of purely philosophical arguments such as "a qubit cannot exist
because its existence is based on the refutation of realism".
In other words, I ask the author to discuss the several claims of
experimental demontrations of quantum advantage/supremacy, i.e. the
simple experimental fact that some tasks can be performed on a quantum
computer with an efficiency not reachable by classical computers. For
instance the google claim:
https://www.nature.com/articles/s41586-019-1666-5 and the most recent
claims by Chinese groups. How do these claims fit with the author's
view?
FInally, but this is a minor point, the sociological (and somewhat
conspirationist) arguments in section 8 can be safely left aside. This
is a journal of physics, not of sociology.
In conclusions, I cannot recommend publication in EPJplus. As a
minimal requirement, the author should at least discuss the points
above.
My reply to Reviewers' comments:
This work “Quantum register cannot be real” was rejected by the Editor
of The European Physical Journal Plus on the basis of the comments of
one Reviewer. The comments were written by a professional who knows
the problems not only of quantum computing, but also of the basics of
quantum mechanics. The Reviewer understands that a quantum computer
can be possible only according to a purely instrumentalist view. He
did not recommend publication of my manuscript in EPJplus because of
two main reasons:
1) The Reviewer follows an instrumentalist view while I do not follow
this point of view.
2) The Reviewer is sure that in a purely instrumentalist view (limited
to mere experimental facts), existing experiments are apparently
supporting the view that quantum computers not only can be built, but
actually work as they are supposed to work. Moreover the Reviewer
assumes that quantum advantage/supremacy was already demonstrated
experimentally. This confidence and this assumption are incompatible
with my point of view, which I prove in the manuscript that a quantum
register is impossible.
I not only do not follow the instrumentalist view I think that this
point of view is misleading. I agree with the criticism of the
instrumentalist view in Chapter 1 “The Theory of Everything” of the
book “The Fabric of Reality” written by David Deutsch, The Father of
Quantum Computing, see
https://www.wired.com/2007/02/the-father-of-quantum-computing/?currentPage=all
. David Deutsch argued in the Chapter "Quantum computers" of the book
[1] that a quantum computer is possible only in the reality of Many
Universes. I quote the Deutsch arguments in my manuscript. But the
Reviewer ignored these arguments, as they contradict his
instrumentalist view.
The Reviewer wrote that “The majority of physicists working in quantum
mechanics are instrumentalists”. It is partly correct, although I am
not sure that all these physicists understand they are
instrumentalists. Almost all authors of publications on quantum
computing certainly follow instrumentalist view, since they ignore the
Deutsch arguments about the possibility of a quantum computer only in
the reality of Many Universes and the Deutsch criticism of the
instrumentalist view in the book [1]. Even if almost all modern
scientists were supporters of the instrumentalist view, this would not
mean that Deutsch's criticism was unfounded. The history of science
shows that the majority are often mistaken. Truth in science is not
determined by voting. Therefore, a point of view that contradicts the
point of view of the majority should not be ignored, much less
prohibited.
Deutsch stated that “For even in purely practical applications, the
explanatory power of a theory is paramount and its predictive power
only supplementary” [1]. He argued that a real device, for example an
interstellar spaceship, can be made on a theory explaining
experimental results rather than a theory which only predicts the
outcomes of experiments. I agree with Deutsch and I have proved in my
manuscript that Deutsch rather than the majority of physicists, who
are instrumentalists, is right. Of course, philosophical arguments
such as "a qubit cannot exist because its existence is based on the
refutation of realism" are not arguments for instrumentalists such as
the Reviewer. But the Reviewer also ignored logical and mathematical
arguments against his belief which are also in my manuscript.
My logical argument reveals that the instrumentalist view is
misleading. The idea of a quantum computer is connected with the
remark made by Richard Feynman and Yuri Manin forty years ago that the
complexity of computing quantum systems increases exponentially with
the number of elements. Feynman and Manin have not understood that the
exponential increase of the complexity takes place not because the
system is quantum, but because the probability of observation is
calculated.
The mathematical expression for a quantum register (the expression (8)
in my manuscript) cannot depend on what is observed: the projections
of spin 1/2, balls of two colors, or Schrodinger’s cats. The results
of the observation of both the projections of spin 1/2 and
Schrodinger’s cats have two possibilities: spin up or spin down; a
live cat or a dead cat. A purely instrumentalist view cannot say what
the quantum register describes: the probabilities of one of the two
possible results of observing the projections of spin 1/2 or
Schrodinger’s cats. Therefore, if a quantum register can be made from
particles with spin 1/2, then it can also be made from Schrodinger’s
cats, according to the instrumentalist view.
My mathematical argument is based on the mathematical fact that the
operators of finite rotations of the coordinate system can be applied
only to non-entangled spin states. Therefore one can say which
coordinate system refers to the given probability amplitudes of the
quantum register only if quantum bits (qubits) of this quantum
register are not entangled. But quantum computing has no advantage if
only non-entangled qubits are used. The advantage of a quantum
computer is in irreconcilable contradiction with its reality according
to logic and mathematics.
I wrote in the manuscript that if someone believes that the quantum
register can be made from particles with spin 1/2 he will have to
answer the question to which coordinate system can belong the
probability amplitudes of this quantum register. The Reviewer ignored
this question since it cannot be answered when spin states are
entangled. I considered the logical argument and the mathematical
argument in two reports “Funny mistake of Richard Feynman” and
“Quantum register cannot be real” presented last year at the
conference "Quantum Informatics — 2021”. The slides of the reports are
available on ResearchGate
https://www.researchgate.net/profile/Alexey-Nikulov :
https://www.researchgate.net/publication/350761689_Funny_mistake_of_Richard_Feynman
https://www.researchgate.net/publication/350754616_Quantum_register_cannot_be_real
. No one has refuted for the present these arguments calling into
question the possibility of a quantum computer. Quantum computing
experts, like the Reviewer, prefer to ignore these arguments.
David Deutsch was following in his criticism of the instrumentalist
view to the opinion of the famous philosopher of the twentieth century
Karl Raimund Popper. Karl Popper wrote in Chapter 3. “Three Views
Concerning Human Knowledge” of the book [2]: “Very few physicists who
now recognize the instrumentalist point of view of Cardinal Bellarmino
and Bishop Berkeley realize that they accept some philosophical
theory. They also do not realize that they are breaking with the
Galilean tradition”. Most physicists, unlike the Reviewer, do not
understand even that they recognize the instrumentalist view when they
believe in quantum mechanics.
Speaking about breaking with the Galilean tradition, Popper meant that
according to the instrumentalist point of view no difference was
between the Ptolemaic system and the Copernican system in the time of
Galileo, since both systems successfully described the results of
observations known in that time. The reason for the conflict with the
Catholic Church was Galileo's assertion that the Copernican system is
not just a more convenient instrument for describing the results of
observations, but is a description of reality. The Galilean tradition
led to space flights, which would hardly have been possible if the
instrumentalist point of view had won. Deutsch was right when he
stated in [1] that an interstellar spaceship cannot be made on the
basis of a theory which only predicts the outcomes of experiments. I
agree with Deutsch and Popper rather than with the Reviewer and the
majority of modern physicists working in quantum mechanics.
In connection with the Reviewer's confidence that quantum computers
not only can be built, but that they actually work, one should recall
another famous philosopher of the twentieth century, Jose Ortega y
Gasset, the great Spanish philosopher according to Schrodinger’s
opinion. Ortega y Gasset was concerned about the fate of science
because of its increasing mass. He wrote in his famous book "The
Revolt of the Masses", published in 1930: “Has any thought been given
to the number of things that must remain active in men’s souls in
order that there may still continue to be “men of science” in real
truth? Is it seriously thought that as long as there are dollars there
will be science? This notion in which so many find rest is only a
further proof of primitivism” [3]. I agree that only dollars cannot
provide the possibility of the true science. Moreover, I think that a
lot of dollars can provoke degradation of science.
I know from experience how difficult it is for most scientists to
admit that the theory they were developing or following for many years
may be false. This display of honesty becomes especially difficult
when scientists have spent a lot of dollars to implement an idea they
believed in. In this case, scientists can willingly or unwittingly
give wishful thinking. Such self-deception is especially possible in
the case of creating a quantum computer, since the definitions of
quantum supremacy, and the quantum computer itself, are extremely
vague. I should clarify that I am proving the impossibility of a
quantum computer based on the EPR (Einstein - Podolsky – Rosen)
correlation. I am proving that such a quantum computer can be possible
only in defiance of logic and mathematics.
[1] D. Deutsch, The Fabric of Reality. The Penguin Press, 1997.
[2] Karl Raimund Popper, Conjectures and Refutations: The Growth of
Scientific Knowledge. Routledge and Kegan Paul, 1963.
[3] J. Ortega y Gasset, The Revolt of the Masses. W. W. Norton and
Company, 1994.