"Borcis" wrote in message
...
Radi Khrapko wrote:
An answer to the Fermi's question, `Where are they?', is
presented.

Strictly speaking, it is answering a different question,
eg "why don't we observe them", implying the original one is rhetorical. I
don't agree that "Where are they?" is rhetorical. It's really not like
there
wasn't a lot of places where we could imagine "them" to be.

The answer is: we are alone because our Universe
is bad for a civilization. The combination of physical constants
does not need to be more fine tuned than is necessary to permit
one civilization and, since extreme fine tuning of the constants
is a very unlikely event, it is most likely that our Universe is
just good enough to permit development of only one
civilization.

Curiously enough, the assumption that we are alone would seem to
allow viewing as "significant fine-tuning" what we would otherwise
have to dismiss as probably irrelevant. Like the size of Moon, or its
apparent
diameter being the same as that of the Sun, say, or a lot of similar
coincidences that characterize our particular environment. I believe it
follows from your assumption that the more direct environment of the
unique
civilization that develops, must be regarded as very special.

The alternative anthropic principle can be
formulated as follows: `It is most likely to observe a universe
in which civilized life is an extremely rare phenomenon.'

Well, the last extremity of rarity is total absence... isn't it painful
that
the truth of your principle is discontinuous as frequency - 0 ?

How do you get at the notion that fine-tuning the universe for an unique
civilization should be less "extreme" than fine-tuning it for many
civilizations ? It seems you imply an appeal to an interestingly
pathological
version of the principle of parsimony.

Regards, Boris Borcic
--
L'anthropie met un terme aux dynamiques


My college astronomy textbook discusses this topic. They point out
that our civilization in a 1,000 years or less could send out seed ships
which would be able to launch another batch of seed ships within
10,000 years, leapfrogging across the galaxy. This process would
cover most of the Milky Way galaxy within a few million years.

Our system came into existence about 5 billion years ago. Using
an estimate of one civilization to every million stars that means
about 100,000 civilizations should have appeared in the preceeding
5 billion years of our galaxy before we came along. Each of these
100,000 civilizations had plenty of time (a few million years to
spread across the galaxy). But there is no evidence.

What could be the reason?

There is no evidence for such a prior civilization because for
some reason they all decide to stay at home. Or they all have
wars which end the civilization before they colonize. What
are the odds of all civilizations suffering this fate or choice?

There could be a civilization but it chooses not to reveal itself.

The reasons above seem pretty unlikely to me. That leaves
some unknown reason or, that civilizations are actually
extremely rare, far fewer than one in a million. Then the
most like cause for such scarcity is physical environment
and the unique series of events which created life on this planet.

"The Teleological Argument explains nothing and is fundamentally flawed
in its logic. In order for life to exist, the universe must have certain
necessary properties, but it does not follow that the universe has those
properties for the purpose of creating life. Likewise, since we exist, it
must be true that the universe has certain properties but it is incorrect to
say that since the universe has certain properties, we must exist."

Excluding creation by a deity, if we turned back the clock on this
planet to 5 billion years ago it would be very, very, very unlikely
that life would re-evolve. There is a huge string of random events
which would need to repeat to build life again and lead to civilization.

How do you get at the notion that fine-tuning the universe for an unique
civilization should be less "extreme" than fine-tuning it for many
civilizations ? It seems you imply an appeal to an interestingly
pathological
version of the principle of parsimony

There is no _purpose_ involved in what you call fine-tuning or evolution.
It is more accurate to call it a comparison of random events repeating
themselves in similar environments. Suppose there are only a trillion
random events which have to repeat identically to evolve life and lead
to a civilization. The odds of that sting of events repeating in this or
a billion universes like this one is vanishingly remote. There are a lot
of unknown variables in the Drake equation. You would have to
assume that only like 50 random events had to repeat in a suitable
environment in the universe to roughly duplicate our history.

Minsky ruled out computer simulations that might evolve life as
we know it for purposes of building consciousness precisely
because of the huge number of random variables involved in
the history of evolution--mind of mankind. I don't like the
term fine-tuning because it suggests an intentional manipulation
of an anthropic nature to a culminating event composed actually
of random happenings along the way which produced the
potential for an observing civilization of a pre-existing process.

Intractably,
Stephen