Redefining Reality - The Intellectual Implications of Modern Science

Probability has long been a part of our descriptions of the physical
world. In statistical mechanics, it is the result of having a large number
of particles. In quantum mechanics, the equations tell us how likely it
is that a system in a combination of possible observable states will be found
in any particular state if we observe it. In chaos theory, the probabilistic
element is different still. In these systems, the behavior is completely
determined by the laws of physics, but the system is so sensitive to initial
conditions that the tiniest change will lead to wildly different results. The
equations that lead to this kind of behavior have unique properties that make
them fascinating to study.
In 1654, a French nobleman, the Chevalier de Méré contacted
the French philosopher and mathematician Blaise Pascal
about a gambling question. Pascal, in turn, contacted the great
mathematician Pierre de Fermat, who answered by creating the
mathematical theory of probability.
A century and a half later, Pierre-Simon Laplace, one of the
greatest geniuses of the 19 th century, became interested in extending
Fermat’s notion of probability beyond games of chance to show
how it functions in science.
An Analytical Theory of
Probability, showed how to use statistical methods to solve
problems in science. His second book, A Philosophical
Essay on Probabilities, argued that the use of probabilities in
science is the result of our own lack of knowledge, not the
result of a world that is in any way random. In this book,
Laplace posited an intellect that has since become known as
Laplace’s demon.
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