Kilogram conflict resolved at last

For decades, metrologists have strived to retire ‘Le Grand K’ — the platinum and iridium cylinder that for 126 years has defined the kilogram from a high-security vault outside Paris. Now it looks as if they at last have the data needed to replace the cylinder with a definition based on mathematical constants.

Source: Kilogram conflict resolved at last : Nature News & Comment

If they are proved right, in 2018, Le Grand K will join the metre as a museum piece. “We’ll keep it,” says Davis, “but it won’t be defining anything anymore.”

A Fictional Compression Metric Moves Into the Real World

It seems that someone would have come up with such a metric by now. But, says Weissman, “there are two communities: the practitioners, who care about running time, and the theoreticians, who care about how succinctly you can represent the data and don’t worry about the complexity of the implementation.” As a result of this split, he says, no one had yet combined, in a single number, a means of rating both how fast and how tightly an algorithm compresses.

Misra came up with a formula (photo above), incorporating both. Along with existing benchmarks the formula creates a metric that the show writers tagged the “Weissman Score.” It’s not a fictional metric: although it didn’t exist before Misra created it for the show, it works and may soon find use in the real world.

via A Fictional Compression Metric Moves Into the Real World – IEEE Spectrum.