Unusual types of gramophone records Sievey. Chocolate records about three inches in diameter, and small players made for them, were marketed as a novelty in Europe in 1903–1904. After a record wore out or ceased to amuse, it could be eaten. In 1973, the Kingdom of Bhutan issued several unusual postage stamps that are playable miniature phonograph records. These thin plastic single-sided adhesive-backed 33 RPM discs feature folk music and tourism information. Not very practical for actual postal use and rarely seen canceled, they were designed as revenue-generating novelties and were initially scorned as such by most stamp collectors. Their small diameters (approximately 7 and
Kinetic diameter (data) points are moving linearly. This data structure is not local because one point may be in many antipodal pairs, and thus appear many times in the kinetic tournament. The existence of a local kinetic data structure for diameter is open. Efficiently maintaining the kinetic diameter of a point set in dimensions higher than 2 is an open problem. Efficient kinetic convex hull in dimensions higher than 2 is also an open problem. P. K. Agarwal, L. J. Guibas, J. Hershberger, and E. Verach. Maintaining the extent of a moving set of points. Kinetic diameter (data) A kinetic diameter data structure