Anders Sandberg wrote:
>
> Hmm...? I don't have the time right now, but there is an argument
> *against* the steady-state theory based on the paucity of aliens in
> Tipler & Barrow's _The Anthropic Cosmological Principle_. They seem to
> reach the exact opposite conclusion than you.
Actually, I reach the same conclusion. Apply YMAOR; if we're early enough, relative to the Big Bang, that we could plausibly be the first intelligent species in the Universe, or at least the lightspeed horizon, then this theory uniquely predicts the Great Silence experience with one reference to the Anthropic Principle.
The steady-state theory predicts steadily shrinking volumes of free space, contactee civilizations, and thus requires continuous references to the Anthropic Principle to establish us as both in free space yesterday and free space today - it predicts the present, but not as a unique result of the past. By YMAOR, this is the less preferable explanation.
The Tiplerian version probably argued that the elder races would be expansionist and Universe-filling, regardless of improbability, if past time extended into infinity; or even a substantially long time compared to the age of the Earth.
"Explain" is not the same thing as "predict". Wheeler's QM interpretation predicts the existence of our world - in fact, it predicts it as a certainty, not just a remote probability. It eliminates the ugly blemish of state-vector reduction, which is incompatible with both relativity and Schrodinger unitary evolution. By Occam's Razor, it is correct. You have to use YMAOR in order to observe that modern QM more "uniquely" predicts our world, as opposed to all the other Wheelerian branches.
Infinite space predicts everything as effectively as Wheeler, which makes it a semi-palatable alternative to a Great Filter Paradox with *no* apparent resolution. It is still unpalatable compared to the idea that Earth lies on the earliest possible edge of the stage where intelligence is possible. The problem is that we can see ancient galaxies with much higher fractions of heavy elements.
--
sentience@pobox.com Eliezer S. Yudkowsky
http://pobox.com/~sentience/AI_design.temp.html
http://pobox.com/~sentience/singul_arity.html
Disclaimer: Unless otherwise specified, I'm not telling you
everything I think I know.