I was reading the science fiction story "the gold at the starbow's end" by poul anderson (I think) which contains an idea for data compression. Poul Anderson suggested that a large number be compressed to the sum or difference of a few high powers of numbers. In the story it was something like "2506 ^ 9994 + 204 ^ 31 - 73." Does this really work? Why isn't it used instead of zip files and such? Would it just cost too much processing time to compress?