<br><div><span class="gmail_quote">On 6/22/06, <b class="gmail_sendername">George Dvorsky</b> <<a href="mailto:email@example.com">firstname.lastname@example.org</a>> wrote:</span><br><br>> "Where is everybody?"
<br><br>The short answer probably is "in front of our faces".<br></div><br>I've dealt with this question previously in several forums including the ExI list years ago. I haven't read the chapter in the SIN where "We are the first" is discussed but I'm reasonably certain Ray's assumptions are faulty (I doubt he read the Matrioshka Brain papers completely and neither he nor Amara Angelica actively participated in the ExI list discussions).
<br><br>There is abundant evidence if you take an unbiased look at the astromical data that the universe is not "pre-development" or "post-development" but is instead in the "mid-development" stage. As a simple example from a recent astronomical report -- what explains the "radio bright" but "visible dark" galaxies? Or what explains all of the "dark energy" or missing "dark matter"? I point some of these and others in my original Matrioshka Brain paper. As a prominent example the "exoplanet" count is now up to about 170 now -- but there is *zero* evidence that they are classical "planets" (instead of say Jupiter Brains).
<br><br>You cannot grasp this problem by thinking about it as a human with a typical human "reproduction" mindset. Human reproduction (and/or colonization) involves a significant loss of information resources when a copy is produced or one colonizes a distant location. We accept that because we haven't had the means to engineer the reproduction (copying) system from scratch. Shift intead to a cellular (duplication) reproduction mindset where you split all of the resources on a relatively equal basis. For JBrains and MBrains you have, relatively speaking, instanteous copying of huge amounts of information (entire human populations worth) in very short periods of time *if* you have very close proximity between the original and the copy. You cannot copy even a femto-subset amount of that information across interstellar distances. So colonization involves information loss costs that we cannot even imagine now. Probes are a relatively useless investment because it is extremely difficult to get back information of any value from a colony. The only colonization and/or copying that occurs that makes sense (to me) takes place during close proximity near-stellar collisions (KT-II copying) and/or galactic collisions (KT-III copying). You *can* do MBrain duplication between a developed and non-developed solar systems at sub-parsec distances without it costing excessive amounts of energy or matter or sacrificing too much information). So the spread rate isn't limited by c or
0.1c as many colonization scenarios postulate but is instead limited by the frequency of high complexity information substrate encountering extremely low complexity information substrate. Such encounters are very infrequent except in dense stellar environments such as globular clusters. If MBrains migrate to outer galactic environments as I have postulated and Milan and I touch upon in the recent New Astronomy paper (this is based on Minsky's observation to Dyson regarding thermodynamic efficiency at the first Byurakan CETI conference in 1971) then the frequency of stellar close encounters is even lower than it is for emerging pre-singularity civilizations in locations similar to those our solar system is currently in.
<br><br>You can't look at the Fermi Paradox and get sensible answers from where we are now with implicit human assumptions. You have to assume full nanotech and singularity development at the limits imposed by a solar system (
i.e. MBrains). Then it starts to make some sense.<br><br>Robert<br><br>Side note: I spent a significant fraction of 1998-2000 reading almost all of the existing SETI literature (including F.P. discussions) and converting it into a hypertext database. I also saw one of Lineweaver's early presentations on his research and cite his work as pointing out how the SETI community collectively isn't thinking about the problem properly. There are probably less than 200 people alive familiar with a reasonable subset of that literature and only a dozen or so who have been given access to the database. If you are asking the question in a blog simply trying to get people to think about it that is fine -- but *unless* you want to educate them with a large body of knowledge I very much doubt you will generate useful insights from the process.