An answer to the Fermi's question, `Where are they?', is
presented. 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. 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.'

Astronomical and Astrophysical Transactions 22 (2003) 847-850

Radi Khrapko

(Radi Khrapko) wrote in message . com...
An answer to the Fermi's question, `Where are they?', is
presented. 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. 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.'

Astronomical and Astrophysical Transactions 22 (2003) 847-850

Radi Khrapko


What on Earth makes you suspect that Earth is the only world with life
in the universe?

"Radi Khrapko" wrote in message
om...

An answer to the Fermi's question, `Where are they?', is
presented. 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. 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.'

Your alternative principle is the result of a completely superfluous
polishing of the anthropic principle - IMHO!

P

(Radi Khrapko) wrote in
om:


An answer to the Fermi's question, `Where are they?', is
presented. 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. 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.'

Astronomical and Astrophysical Transactions 22 (2003) 847-850

This is an interesting idea, but the answer is far from obvious. Assume
that there are 100 universes where intelligent life is so unlikely to occur
that it only happens on one place and 1 universe where it is a bit more
likely so it exist on 900 planets. Then there is 90% probability that we
live in the last one, even if most of the universes where life can occur
are more hostile.

By observing how common life is we may then draw some conclusion about
exactly how sensitive the parameters are that control the likelyhood of
life in the universe, although obviously statistics based on a single
sample is chancy.

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 answers to Borcis
From : Borcis
Sent : Wednesday, December 24, 2003 7:17 PM
To : Radi Khrapko
Subject : A New Anthropic Principle
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.

My answer is: "They are nowhere"

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.

Sorry, I don’t understand your thought. Please, say it in other
words.

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 ?

No, it isn't painful: the probability of my occurrence in the universe
is zero. However I observe myself

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.

Sorry, what is the principle of parsimony?
I think that among anthropic universes there are universes that are
more or less favorable for civilizations, and, if the probability of
an anthropic universes is very small against the background of all
universes, it is natural to expect that the probability of a universe
especially favorable for civilizations will be very small against the
background of universes that admit only one civilization and, in
particular, that are rather adverse marginal universes adjoining
non-anthropic universes.

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

Radi Khrapko

This is an interesting idea, but the answer is far from obvious. Assume
that there are 100 universes where intelligent life is so unlikely to occur
that it only happens on one place and 1 universe where it is a bit more
likely so it exist on 900 planets. Then there is 90% probability that we
live in the last one, even if most of the universes where life can occur
are more hostile.

I cannot assume this. I can assume that there is 1 universe where it
is a bit more likely so intelligent life exists on 2 planets.

By observing how common life is we may then draw some conclusion about
exactly how sensitive the parameters are that control the likelyhood of
life in the universe, although obviously statistics based on a single
sample is chancy.

Life is common on the Earth only

Radi Khrapko

Radi Khrapko wrote:


Life is common on the Earth only

You ought to say we have the only live planet in the neighborhood. If
there were a planet one million light years away just teeming with
intelligent (and non-intelligent) life, it would be of no consequence to
us.

There could be a thousand planets in the Milky Way with highly
intelligent life, but so far seperated as to make interaction a
practical impossibility.

Bob Kolker

What on Earth makes you suspect that Earth is the only world with life
in the universe?

My thoughts on Earth make me suspect that Earth is the only world with
life in the universe.
You can see the full text: http://arxiv.org/abs/physics/0105031

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.

An interesting er, counterweight variant, is the belief that in a small
billion years, dozens of the closest galaxies of the Universe will be ablaze
with signs of life from end to end, but just right now or about, billions upon
billions of intelligent planetary civilisations reach the step of willfully
conquering the scales upward to make that happen, while being yet at 99.99%
outside of each other's cosmological horizon.

This is a radical but beautifully simple hypothesis, the "Universal Biological
Clock Diagonal Hypothesis". Jingle : "God grows SIGNIFICANT Mathematicians
Everywhere in the Universe in an Amount of Locally Elapsed Time since the Big
Bang that's Unexpectedly Uniform and Precise"

.... and presumably (slightly ?) above our own universal age

Cheers, B.