simsim314 wrote:I still don't see the point of imagining and hoping for some miracle, instead of investing effort to build something which is known to be possible to build and will certainly work.
I lean toward that point of view also -- but I think I understand muzik's point of view pretty well also. No matter how impressive an engineered universal spaceship gets built, it won't change the annoying fact that there are gaps in the Elementary Spaceships
It wouldn't be so bad if we could be sure that no spaceships exist at those speeds... but I think we can guess fairly confidently that c/8 and c/9 elementary spaceships _do_ exist, at some size. But the search haystack is so large that we can't find the needle...
It's interesting that what our search tools are good at finding is long thin / short wide / diagonally narrow spaceships, but for most periods those probably aren't the smallest population ships that are out there. If we could inspect all the record-breaking smallest period-N ships stored in Plato's Cave, from N=2 to N=very large, it seems to me they'd probably mostly be fairly thin fairly short asymmetical blobs -- getting bigger on average as the period goes up, but not getting up as far as Spaghetti Monster length for quite a while.
Has anybody tried a lifesrc-like search that's not exhaustive, but instead makes arbitrary decisions every now and then and skips large parts of the search space? Maybe a workable way to find a blob-shaped higher-period spaceship would be to set a randomized lifesrc running for a few months. Every time it gets to the end of a search cycle in less than an hour, it should cut its probability of making an arbitrary choice by say 10% -- and every time a search cycle takes more than an hour it should increase that probability by 10%.
That would at least search different corners of the search space on every cycle. If there are a lot of spaceships out there in the search space, it might be more likely to happen on one, than an exhaustive lifesrc algorithm that keeps getting stuck trying every possibility in some useless corner of the space.
-- Probably not, though. The great advantage of exhaustive searches is that if you can get all the way through one, you've actually learned something. Running a randomized searcher would probably get discouraging fairly quickly.