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Optimal Golomb Rulers

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Before diving into this article on the OGR project, we recommend that you gain some background knowledge of Golomb Rulers. Click on the graphic above to begin. Flash plug-in is required.

Golomb rulers were discovered by Solomon W. Golomb, a mathematics professor with an interest in coding, combinational analysis, and mathematical puzzles. In fact, his interest and contributions to the Scientific American "Mathematical Games" led to the existence of Golomb Rulers. ("distributed.net: Project OGR) Golomb rulers are numbers in such an order that each pair of numbers has a unique difference from all other pairs. A Golomb ruler with only three marks would be 0-1-4. The distances between each of the numbers are 1, 3, and 4. An optimal Golomb ruler with four marks is 0-1-4-6. The distances between each of those numbers are 1, 2, 3, 4, 5, 6. Thus, the marks have the most unique differences but the ruler is short in length. The length is six, since six is the total distance from 0-6. However, Golomb rulers are usually characterized by their differences; the above ruler would be 0-1-3-2. When the rulers are written this way, the lengths can be found by adding all of the differences.

Optimal Golomb rulers may appear to be simple number patterns, but they are incredibly useful. Optimal Golomb rulers — also referred to as OGR — are used in numerous fields of study, such as laser technology, crystallography, and radio astronomy. They can even be used in cryptography. The Internet hadn't been exposed to a Golomb ruler distributed computing project until a now-defunct group created programs called GARSP and GVANT. (Garry) Although this OGR groupšs efforts were somewhat in vain- they didn't find any new optimal rulers; they only proved that the current 21, 22, and 23 mark optimal Golomb rulers were, in fact, optimal- they opened the possibility for distributed computing techniques to search for a larger optimal ruler.

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