[word=□]
[word=rings]
However , we do n't have to have secret decoder rings since we can use clock arithmetic to do the same thing that the decoder rings did . Check out the Resource Guide for Teaching Astronomy through Science Fiction , an annotated index to science fiction stories and novels that use good astronomy , available on the education web pages of the nonprofit Astronomical Society of the Pacific , with categories from anti-matter to Venus , plus exploding stars , the future exploration of Mars , falling into a black hole , the search for intelligent life in the universe ( and what forms it might take ) , and what it would be like to live among the rings and moons of the outer solar system . NetMod includes models for network technologies such as token rings , Ethernet , metropolitan , and wide-area networks ; individual or groups of computers and engineering workstations ; and special network interface components such as routers , bridges , and point-to - point links . The Cassini spacecraft gazes down through the dark side of Saturn ’ s rings toward the softly glowing planet . ) Nonsingular points on the variety correspond to regular local rings , which obviously can be expected to be better behaved ( for example , Serre proved these are the local rings of finite global dimension ; Auslander-Buchsbaum showed all are unique factorization domains ) and which are of wide applicability in commutative algebra .