MI weekly selection #57

Tsinghua multiplication table_bamboo strips2.jpg

Ancient strips of bamboo hold multiplication table

A multiplication table in base 10 has been revealed in ancient strips of bamboo found in China that date back to around 305 B.C. About 2,500 bamboo strips were donated to Tsinghua University in Beijing five years ago, and researchers discovered ancient Chinese calligraphy written on the strips that they pieced together like a puzzle. Of those strips, 21 contained only numbers, which researchers found was a multiplication table.

Nature News

 

Astronomers measure distances between galaxies with 1% accuracy

The Baryon Oscillation Spectroscopic Survey, known as BOSS, has measured the distances between galaxies within 1% accuracy, it was announced at an American Astronomical Society meeting in Washington, D.C. The team used baryon acoustic oscillations as a ruler to measure distances between galaxies.

BBC

 

19th-century cholera strain differs genetically from current forms

Scientists have mapped the genome of a 19th-century strain of cholera that spread through Europe and North America, and have found it distinctly different from the strains of cholera in the world today. The most prevalent strain of cholera today is known as El Tor, which has one less set of genes than the more classical strain.

Nature news

 

Metamaterials used to perform math functions

Metamaterials, which bend light in unusual ways, are being used to create a variation on the analog computer capable of performing mathematical functions. Researchers have simulated a metamaterial that can perform calculus and other fundamental mathematical functions by modifying a light wave’s profile: as the wave goes through the metamaterial, its profile changes such that by the time it comes out, it has the profile expected from the given mathematical operation.

New Scientist

 

Prairie dogs jump to test neighbors’ awareness

Prairie dogs exhibit contagious displays of communication very much like the wave seen at sports stadiums around the world. “This work reveals that black-tailed prairie dogs use contagious ‘jump-yip’ displays to probe the responsiveness of their neighbors, effectively testing their level of vigilance, and adjusting their behavior according to how much they can rely on their neighbor’s awareness of potential risks in their environment,” said James Hare of the University of Manitoba in Canada, a co-author of the study.

National Geographic / Weird & Wild

 

 

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