Essay About Matter Of Common Experience And Ordered System

Life In The Universe
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Life in the Universe
In this talk, I would like to speculate a little, on the development of life in
the universe, and in particular, the development of intelligent life. I shall
take this to include the human race, even though much of its behaviour
through out history, has been pretty stupid, and not calculated to aid the
survival of the species. Two questions I shall discuss are, What is the
probability of life existing else where in the universe? and, How may life
develop in the future?
It is a matter of common experience, that things get more disordered and chaotic with time.
This observation can be elevated to the status of a law, the so-called Second Law of
Thermodynamics. This says that the total amount of disorder, or entropy, in the universe,
always increases with time. However, the Law refers only to the total amount of disorder. The
order in one body can increase, provided that the amount of disorder in its surroundings
increases by a greater amount. This is what happens in a living being. One can define Life to
be an ordered system that can sustain itself against the tendency to disorder, and can
reproduce itself. That is, it can make similar, but independent, ordered systems. To do these
things, the system must convert energy in some ordered form, like food, sunlight, or electric
power, into disordered energy, in the form of heat. In this way, the system can satisfy the
requirement that the total amount of disorder increases, while, at the
same time, increasing the order in itself and its offspring. A living being
usually has two elements: a set of instructions that tell the system how
to sustain and reproduce itself, and a mechanism to carry out the
instructions. In biology, these two parts are called genes and
metabolism. But it is worth emphasising that there need be nothing
biological about them. For example, a computer virus is a program that
will make copies of itself in the memory of a computer, and will transfer
itself to other computers. Thus it fits the definition of a living system,
that I have given. Like a biological virus, it is a rather degenerate form,
because it contains only instructions or genes, and doesnt have any
metabolism of its own. Instead, it reprograms the metabolism of the
host computer, or cell. Some people have questioned whether viruses
should count as life, because they are parasites, and can not exist
independently of their hosts. But then most forms of life, ourselves included, are parasites, in
that they feed off and depend for their survival on other forms of life. I think computer viruses
should count as life. Maybe it says something about human nature, that the only form of life we
have created so far is purely destructive. Talk about creating life in our own image. I shall
return to electronic forms of life later on.
What we normally think of as life is based on chains of carbon atoms, with a few other atoms,
such as nitrogen or phosphorous. One can speculate that one might have life with some other
chemical basis, such as silicon, but carbon seems the most favourable case, because it has the
richest chemistry. That carbon atoms should exist at all, with the properties that they have,
requires a fine adjustment of physical constants, such as the QCD scale, the electric charge,
and even the dimension of space-time. If these constants had significantly different values,
either the nucleus of the carbon atom would not be stable, or the
electrons would collapse in on the nucleus. At first sight, it seems
remarkable that the universe is so finely tuned. Maybe this is
evidence, that the universe was specially designed to produce the
human race. However, one has to be careful about such
arguments, because of what is known as the Anthropic Principle.
This is based on the self-evident truth, that if the universe had not
been suitable for life, we wouldnt be asking why it is so finely
adjusted. One can apply the Anthropic Principle, in either its
Strong, or Weak, versions. For the Strong Anthropic Principle, one supposes that there are
many different universes, each with different values of the
physical constants. In a small number, the values will allow the
existence of objects like carbon atoms, which can act as the
building blocks of living systems. Since we must live in one of
these universes, we should not be surprised that the physical
constants are finely tuned. If they werent, we wouldnt be
here. The strong form of the Anthropic Principle is not very satisfactory. What operational
meaning