«Einstein once asked
his young friend Abraham Pais
if the Moon existed only
when someone was looking at it».
Esta fue la misma pregunta
que una mañana
del primer semestre del año 1970,
dejó flotando en el aire
el Father Provenzano,
cuando todavía el colegio
Saint George tenía su sede
en la avenida Pedro de Valdivia 1423.
Mi banco
estaba pegado a la ventana,
detrás del de Radovic,
quien se caraterizaba
por su simpatía e inteligencia
(sin mencionar el espectacular
Mustang Mach 1 de color verde)
y por el tamborileo de su lápiz
a mina, mientras pensaba...
Algunos hicieron rápidamente
diversas conjeturas,
u opinaron a favor y en contra.
El sabio Provenka,
que sabía que esa
inocente pregunta
sería objeto de debate
más allá de su estadía
en este mundo,
siguió con su clase,
con sus quizes,
y las materias
y experimentos
que se proponían
en el par de volúmenes
del PSSC: Physical Science
Study Committee, que todavía
tengo en un estante contiguo,
como para recordarme
cada vez que contemplo
la luna suspendida sobre
el cerro Manquehue,
la pregunta que dejó
flotando en el aire
el riguroso, íntegro
y a la vez bondadoso
curita de la Holy Cross.
------
Einstein’s Moon
D. Song
School of Liberal Arts,
Korea University of Technology & Education,
Chungnam 330-708, Korea
An account of the subjective elements
of quantum mechanics or of whether,
as Einstein famously asked,
the Moon exists when nobody is looking at it.
Einstein was not very happy
with quantum theory,
for a very good reason.
Quantum theory is probabilistic
at the fundamental level.
Well, you may ask,
what can be so wrong
about the theory being probabilistic?
Science is based on causality;
that is, for every result, there is a cause.
If the theory is probabilistic,
it means the result appears
to happen without a definite cause.
This seems to be problematic
as far as causality is concerned
(see [1, 2] for a review).
Moreover, this probabilistic
nature of quantum theory
happens when there is
a measurement or observation.
Again,
what is the big deal
with the theory
involving the observation?
Is science not all about
experiments and observations?
In case of quantum theory,
the problem is that
the observation often changes
the status of the observed physical system.
In other words,
subjectivity is an essential
element of quantum theory.
This was something Einstein,
and many other people, could not take.
They thought that science
should provide a consistent truth
about an objective reality
rather than something that varies
depending on a subjective perspective.
This sounds very reasonable.
Or does it not?
Experiments or observations
form the basis of science.
Although we often think
science provides an objective law
about physical systems, in fact,
it yields a rule about the way
we observe physical systems.
This was true
even before
quantum theory,
when distinction
was not necessary
to improve predictability;
it only added extra burden.
However,
with the development
of quantum theory
at the beginning
of the 20th century,
the subjective
aspect of science
finally began to emerge
and it started to matter,
even in terms
of actual predictability.
In other words,
quantum theory started
to reach the ultimate
limit of science, subjectivity.
The idea of subjectivity is nothing new.
Philosophers have been
talking about it for centuries.
Descartes argued that at least
the subjective thought itself
was certain to exist,
which he expressed
in the well-known statement
“I think, therefore I am.”
Even in the 20th century,
many philosophers discussed
the subjective nature
of existence itself.
However,
is it possible to argue
this scientifically
rather than philosophically?
Is it possible
to write down
a precise and exact
mathematical equation
and show that existence
is indeed subjective?
In [3], it was shown
that it is not possible
to separate the observer
from the observed
using quantum theory.
That is, physical systems,
including atoms, the Moon,
or the whole universe,
do not exist in separate
from my own existence.
However, was the argument scientific?
Was it mathematically precise and exact?
The great power of quantum theory
lies in its preciseness and exactness.
That is, a state vector,
a mathematical representation
of the physical system,
is a full and exact description.
What comes next is even better.
When observing the state vector,
one needs to be in a certain reference frame,
called an observable in quantum theory.
An amazing part
is that this reference frame
is also full and exact,
just like the state vector.
Okay, one may argue,
you can represent the physical system
and the reference frame of the observer exactly,
but this does not mean the universe is subjective.
When you have this exact representation
for the physical system and the observer,
there is symmetry between
the observer and the observed.
Consider a rotational symmetry.
That is,
if the system were rotated clockwise
or if you were rotated counterclockwise,
you would observe exactly
the same thing on both occasions.
The symmetry between
the object and the observer
explains the phenomenon;
it is called the Schrödinger
and the Heisenberg picture
in quantum theory.
Why does this prove
the universe is subjective?
We experience
some very strange phenomenon
where this symmetry
between the object
and the observer breaks down.
This phenomenon is consciousness!
In consciousness,
one experiences the observation
of one’s own mental state,
sometimes called self-awareness
or reflexive self-consciousness.
This is unique.
The person is both
the observer
and the very object
that is being observed.
Because of consciousness,
the symmetry, established
on exact and precise
mathematical representation
of the object and the observer,
is no longer valid.
That is, one cannot separate
the object from the observer.
If the universe is the object
that is being observed,
then the universe has
to be subjective as well.
Einstein once asked
his young friend Abraham Pais
if the Moon existed only
when someone was looking at it [4].
Does the Moon, indeed,
exist only when I observe it?
If we assume that the Moon
obeys quantum theory
and the unique property
of consciousness,
as strange and counter-intuitive
as it may seem, the Moon
may not exist in separate
from my own existence.
References
[1] A. Peres,
Quantum theory: Concepts and Methods,
Kluwer Academic publishers (1995)
[2] M.A. Nielsen and I. L. Chuang,
Quantum Computation and Quantum Information,
Cambridge University Press (2000).
[3] D. Song,
Unsolvability of the halting problem in quantum dynamics,
Int. J. Theor. Phys. 47, 1785 (2008)
[4] A. Pais,
Einstein and Quantum theory,
Rev. Mod. Phys. 51, 863 (1979).
__________________________________________
arXiv:1008.2892v2 [physics.gen-ph] 16 Apr 2013
__________________________________________
Philosophical roots
of the "eternal" questions
in the XX-century theoretical physics
V. Ihnatovych
Department of Philosophy,
National Technical University of Ukraine
“Kyiv Polytechnic Institute”, Kyiv, Ukraine
e-mail: V.Ihnatovych@kpi.ua
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