QUANTUM METAPHYSICS - E-thesis

In the EPR state, the wave function is formed out of the non-separable superposition of both
particles. According to the formalism, the parts of the system are correlated and observing one
particle has an instantaneous effect on the other particle, regardless of the distance that separates
them. Objects which have once been interacted with are no longer completely isolated, they are
internally connected with each other in a manner incomprehensible to classical physics. This new
feature of quantum mechanics allows new options for example for the storage, transfer and
handling of information. It is believed that superposition phenomena and entanglement can be
exploited in quantum computers by coding information to two states quantum-mechanics
systems, i.e. as quantum bits. In this conditional logic, a change in state of one bit is dependent
on the state of the other and as a result of the operations the states of the quantum-bits become
entangled. In quantum calculations, on the other hand, entanglement is also a severe problem,
since if the quantum computer is not located in a totally isolated situation, a quantum computer
and the state of its environment will be entangled by virtue of their interaction. In such a case,
the quantum system would move from being a pure state to a mixed state and part of the
information it contained would be lost. 536
The Copenhagen group clearly recognized and drew serious attention to this novel holistic
feature inherent in the world described by quantum mechanics. Bohr debated it for decades with
Einstein, who did not accept Bohr’s thinking that quantum mechanics required a radical renewal
of the framework of description employed by classical physics and wanted to hold on the
traditional objective, deterministic and localised
concept of reality. The result was a decades-long debate conducted at scientific conferences and
in private correspondence. 537 Although the controversy concerned the consistency and
completeness of quantum mechanics, its foundation was a difference in conceptions of reality. 538
During the dispute, a majority of physicists considered Bohr’s position to be the more durable
one, even though in Einstein’s own time, his stubbornness had some justification. In the light of
subsequent experimental work, the holistic features of quantum mechanics and their ontological
implications are much harder to deny. Even today, opinion is however not unanimous about
whose arguments won the day. 539
536 The impediment resulting from decoherence typically grows in an exponential manner related to the size of the
quantum system. For this reason, it is difficult to observe or build macroscopic quantum systems.
537
The debate is discussed in more details in Section 4.1.1.
538
Hooker 1972, 77-78.
539
Beller and Fine 1994, 29.
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