12-03, 16:40–17:00 (Europe/Luxembourg), Banquet Room
Background
Self-replicating starships are an inevitable evolution from interstellar starships that can self-repair in-transit. They offer the most economic means through which to explore our Galaxy at a capital cost of launching a single or a few starships. Tipler suggested that any technologically-competent extraterrestrial intelligence (ETI) would inevitable adopt this strategy. We further suggest that this strategy is logical for global defence – it provides both intelligence about potential threats in our Galactic environment and security regarding the location of our home world. Sagan suggested that no responsible ETI will adopt self-replicating starships as they are potentially uncontrollable because of their evolvability.
Objective
We propose that prevention of evolutionary change in the self-replicating starship’s genetic information is feasible.
Methods
We review error detection and correction coding (EDAC) methods utilised extensively in spacecraft onboard memories to combat incident radiation. Evolutionary mutation can be prevented to any arbitrary degree through channel coding which ensures the fidelity of information through a communications channel – in this case, a vertical evolutionary channel. Biological genetic fidelity is limited by the energy cost of physical repair mechanisms but spacecraft memory-encoded binary information repair involves only bit flipping. There are two major types of EDAC and variations thereof - block coding and convolutional coding – which add redundant information. Interleaved Reed-Solomon block coding with convolutional coding is commonly implemented for reliable interplanetary data transmission, e.g. Voyager. Turbo coding approaches the maximum encoding efficiency dictated by Shannon’s theorem. For a self-replicating probe to spread through the Galaxy requires copying fidelity over only 24 vertical generations. We might employ deeper encoding depth at critical genetic instructions such as number of offspring and telomeric counters.
Results
Efficient channel coding can prevent mutations generated by copying errors in the genetic code of the self-replicating starship thereby preventing it from evolving.
Conclusions
The Sagan-Tipler debate regarding the existence or non-existence of ETI revolved around their deployment of self-replicating probes to permeate the Galaxy within astronomically short timescales. Sagan’s retort is unfounded. Fearfulness of technology has never been much of a deterrent for humans so its application to ETI contravenes the Copernican principle.
