Megascopic Quantum Phenomena
295
be either alive or dead yet before the box was opened. Carpenter and Anderson
further analysed the laboratory thought experiment with the following conclusion
[20]: “The implications arising from the “Schrödinger’s cat” thought experiment have
led some authors to argue that observation of a measurement by a conscious observer
is required to collapse quantum wave-functions. Here we combine Schrödinger’s
experimental paradigm with a system for splitting the information about the quantum
state between two observers, thereby allowing distinct outcomes to be recorded
without either observer knowing the state of the measured quantum event. Our results
imply that to collapse a quantum wave-function, measurement alone, rather than
conscious observation of a measurement, is sufficient.”
The last objection made by Einstein against the Copenhagen interpretation was
published in his Reply to Criticisms in 1949 [19], which runs in analogy with
Schrödinger’s cat argument: “As far as I know, it was E. Schrödinger who first called
attention to a modification of this consideration, which shows an interpretation of
this type to be impracticable. Rather than considering a system which comprises only
a radioactive atom (and its process of transformation), one considers a system which
includes also the means for ascertaining the radioactive transformation—for example, a Geiger-counter with automatic registration-mechanism. Let this latter include
a registration-strip, moved by a clockwork, upon which a mark is made by tripping
the counter. True, from the point of view of quantum mechanics this total system is
very complex and its configuration space is of very high dimension. But there is in
principle no objection to treating this entire system from the standpoint of quantum
mechanics. Here too the theory determines the probability of each configuration of
all its co-ordinates for every time instant. If one considers all configurations of the
coordinates, for a time large compared with the average decay time of the radioactive
atom, there will be (at most) one such registration-mark on the paper strip. To each
coordinate configuration corresponds a definite position of the mark on the paper
strip. But, inasmuch as the theory yields only the relative probability of the thinkable
co-ordinate-configurations, it also offers only relative probabilities for the positions
of the mark on the paper strip, but no definite location for this mark.”
Yet again, cf. the case of gunpowder pile, Einstein’s critique was justifiable, and
hence there exists until now no resolution to this paradox. Nevertheless, for Einstein
the only way out was the acceptance of the statistical interpretation of quantum
mechanics, which today is not the accepted majority standpoint. “One arrives at very
implausible theoretical conceptions, if one attempts to maintain the thesis that the
statistical quantum theory is in principle capable of producing a complete description
of an individual physical system. On the other hand, those difficulties of theoretical
interpretation disappear, if one views the quantum-mechanical description as the
description of ensembles of systems” [19].
As the Schrödinger’s cat has inspired many new interpretations of quantum theory,
Schreiber in his Master of Science thesis, made an extensive comparison of them
and wrote a very nice parody “The Nine Lives of Schrödinger’s Cat” [21] where he
describes the fate of the poor cat in the nine most popular alternative interpretations.
In his conclusion, he says: “Discussion: The orthodox interpretation works well in
practice but is ambiguous and therefore unacceptable. Bohr’s epistemological views
295
be either alive or dead yet before the box was opened. Carpenter and Anderson
further analysed the laboratory thought experiment with the following conclusion
[20]: “The implications arising from the “Schrödinger’s cat” thought experiment have
led some authors to argue that observation of a measurement by a conscious observer
is required to collapse quantum wave-functions. Here we combine Schrödinger’s
experimental paradigm with a system for splitting the information about the quantum
state between two observers, thereby allowing distinct outcomes to be recorded
without either observer knowing the state of the measured quantum event. Our results
imply that to collapse a quantum wave-function, measurement alone, rather than
conscious observation of a measurement, is sufficient.”
The last objection made by Einstein against the Copenhagen interpretation was
published in his Reply to Criticisms in 1949 [19], which runs in analogy with
Schrödinger’s cat argument: “As far as I know, it was E. Schrödinger who first called
attention to a modification of this consideration, which shows an interpretation of
this type to be impracticable. Rather than considering a system which comprises only
a radioactive atom (and its process of transformation), one considers a system which
includes also the means for ascertaining the radioactive transformation—for example, a Geiger-counter with automatic registration-mechanism. Let this latter include
a registration-strip, moved by a clockwork, upon which a mark is made by tripping
the counter. True, from the point of view of quantum mechanics this total system is
very complex and its configuration space is of very high dimension. But there is in
principle no objection to treating this entire system from the standpoint of quantum
mechanics. Here too the theory determines the probability of each configuration of
all its co-ordinates for every time instant. If one considers all configurations of the
coordinates, for a time large compared with the average decay time of the radioactive
atom, there will be (at most) one such registration-mark on the paper strip. To each
coordinate configuration corresponds a definite position of the mark on the paper
strip. But, inasmuch as the theory yields only the relative probability of the thinkable
co-ordinate-configurations, it also offers only relative probabilities for the positions
of the mark on the paper strip, but no definite location for this mark.”
Yet again, cf. the case of gunpowder pile, Einstein’s critique was justifiable, and
hence there exists until now no resolution to this paradox. Nevertheless, for Einstein
the only way out was the acceptance of the statistical interpretation of quantum
mechanics, which today is not the accepted majority standpoint. “One arrives at very
implausible theoretical conceptions, if one attempts to maintain the thesis that the
statistical quantum theory is in principle capable of producing a complete description
of an individual physical system. On the other hand, those difficulties of theoretical
interpretation disappear, if one views the quantum-mechanical description as the
description of ensembles of systems” [19].
As the Schrödinger’s cat has inspired many new interpretations of quantum theory,
Schreiber in his Master of Science thesis, made an extensive comparison of them
and wrote a very nice parody “The Nine Lives of Schrödinger’s Cat” [21] where he
describes the fate of the poor cat in the nine most popular alternative interpretations.
In his conclusion, he says: “Discussion: The orthodox interpretation works well in
practice but is ambiguous and therefore unacceptable. Bohr’s epistemological views