A mathematical term referring to a set of non-negative integers such that no two distinct pairs of numbers from the set have the same difference. In real world terms, its a ruler with no pair of marks measuring the same distance. Useful in fields such as X-ray crystallography and radio astronomy.
The current best known Golomb ruler is:
0-2-22-32-21-5-1-12-34-15-35-7-9-60-10-20-8-3-14-19-4. Testing for new rulers becomes exponentially difficult, and has become the task of distributed.net's OGR competition. | 
