On Sunday, January 12, 2003, at 05:38 PM, Russell Standish wrote:
The key assumption here is whether advanced technological civilisationI cannot understand why you would say "contra to your comments below" when in several places I discussed this issue of how common life is:
(such as ourselves) is easy or difficult on the timescale of the age
of the universe (10^10 years).
Assuming that this is difficult (contra to your comments below),
solves the standard Fermi paradox (namely other advanced civilisation
are too far away to have reached us yet, and probably too far away to ever
reach us, unless the universe starts contracting again.
So your Throgians are as good as mythical.
"... estimates of likelihood of advanced civilizations elsewhere. If we are the only form of life in our timelike region of the universe, i.e., within a few billion light-years, then of course this makes the odds of another receiver-builder nil."
"My hunch is that alien civilizations may well exist, but are not abundant "
I made no assumptions of nondifficulty (to use your phrasing).
This is in fact why I picked the Thogians a few hundred million light-years from us. Now perhaps you think advanced civilizations are even rarer than in this example, there have not yet been any civilizations reaching our level, except ourselves, anywhere within a billion light-years or so of us. Arguing this one way or another was not my point.
Rather, it is that the effects of MWI communication (or time travel) would likely be enormous and that such a civilization would be expected to expand and show themselves in the (likely) billion or more years they would have had to expand, build Dyson spheres and other cosmic artifacts, send signals, etc.
I'm not following this at all. Why do you think that communication with (or actual travel to) worlds is dependent on our ability to _predict_ things about them?This also implies that such technological civilisations are also rather diffuse within the Multiverse, _excepting_ of course those which share part of their history with ours (eg the Nazis which won WWII). We have some predictive power as to what those people would be like, since they will be similar to us.
I can see an argument to be made that only close worlds can be communicated with, and some folks have argued this, but this argument was not made by you here.
What I said was that the point that we have not yet built a receiver or portal says nothing about what others have done. And if there are other civilizations out there and building such receivers or portals is possible, one would expect a fair number of them to have done so. Since the implications of building such portals are, I think, enormous, I would expect a civilization which has built such things to have expanded even more rapidly through their part of the universe than without such things.So, I for one, would not discount Hal Finney's point.