dvgrn wrote:That kind of hand-waves past the problem of dealing with the messy junction between leading and trailing GPSEs. Still, someone could maybe try designing an appropriate Corderrake fleet, and see where the problems turn up.
There's an 'instance of junk' at the 'messy junction', so we survive.
In the spirit of trying to avoid Computational Masochism, might it not be a good idea to build everything that it's possible to build -- directly, by taking bits from the Cordership to run the construction arm -- before doing the cleanup?
It seems as if any final target object will have to be constructed by triggering a huge one-glider seed
in any case (because said object can only be safely built after the UCC self-destructs -- it might be a spacefilling breeder or some such).
That being true, isn't it possible to leave completely empty the quadrant of the Life universe where the construction arm is aimed? If so, we might as well build the seed constellation there sooner rather than later.
If we can send slow salvos out to build Corderrakes, aimed at "instances of junk", we can do that right away -- they certainly won't catch up with the GPSEs.
However, I suspect that in some cases, a Corderrake will have to run to completion before the next Corderrake-making slow salvo can be sent out aimed at the next "instance of junk". In that case, that second slow salvo will have to be freeze-dried into a seed constellation -- which can also be built in advance and assigned a location in the Empty Quadrant.
My question is, for just a regular construction -- building a weekender with 59 gliders instead of 79, let's say -- are there any bits coming in from the Cordership that really have to be stored in a memory structure by the UCC? Or can the construction arm just directly build everything that needs to be built?
As soon as we start considering patterns that build copies of themselves, like the 295-cell Yottabyte Universal Constructor Knightship, we're out of luck -- some huge amount of data or other will have to be used after the GPSE cleanup is complete, so that data will have to be stored somewhere. But I'm not clear yet on whether that's true for "simple" constructions like a weekender, or only for truly ridiculous thought experiments like a YUCK.