KritonK writes:
"On February 19, distributed.net began project OGR-28, the challenge to discover the Optimal Golomb Ruler with 28 marks. The previous challenge, OGR-27, is almost complete, with only 9 stubs remaining to be processed, as of February 19. People participating in that challenge do not need to update their client, as it can also process stubs for the new challenge."
(Score: 1) by naubol on Friday February 21 2014, @04:02AM
How do they know, they tried every permutation of numbers up to the current shortest?
(Score: 1) by KritonK on Friday February 21 2014, @08:40AM
If you are asking how they know that rulers with length up to 26 are optimal, yes, they tried every possible permutation!
If you are asking how they know that the optimal ruler with length 27 is shorter than they shortest currently known, without having performed the brute force calculation, well, they don't. It's just a sense that they have. Those who understand the math might be able to explain why there is a high probability that the heuristically found ruler is not optimal. As for me, I'll stick to my pessimism.