Perfect Ruler

A type of Ruler considered by Guy (1994) which has distinct marks spaced such that the distances between markscan be used to measure all the distances 1, 2, 3, 4, ... up to some maximum distance . Such a ruler can beconstructed from a Perfect Difference Set by subtracting one from each element. For example, the PerfectDifference Set gives 0, 1, 4, 6, which can be used to measure , , , ,, (so we get 6 distances with only four marks).

References

Guy, R. K. ``Modular Difference Sets and Error Correcting Codes.'' §C10 in Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, pp. 118-121, 1994.

• Cluster Perimeter
• C-Matrix
• Coanalytic Set
• Coastline Paradox
• Coates-Wiles Theorem
• Coaxal Circles
• Coaxaloid System
• Coaxal System
• Cobordant Manifold
• Cobordism
• Cobordism Group
• Cobordism Ring
• Cochleoid
• Cochleoid Inverse Curve
• Cochloid
• Cochran's Theorem
• Cocked Hat Curve
• Cocktail Party Graph
• Coconut
• Codazzi Equations
• Code
• Codimension
• Coding Theory
• Coefficient
• Coefficient Field