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The Worlds Smallest Fish is described in magazine PNAS

It is called Paedocypris progenetica and belongs to the Cyprinidae family. It is endemic to the Indonesian islands of Sumatra and Bintan where it is found in peat swamps and blackwater streams. Females reach maximum of 10.3 mm, males 9.8 mm. It held the record for the smallest known vertebrate until the frog Paedophryne amauensis was described.

Opportunity rover lands on surface of Mars

It landed three weeks after its twin Spirit. The landing site was in Meridiani Planum. It is a plain which hosts a crystalline hematite. On Earth, hematite is often formed in hot springs or in standing pools of water. Some people therefore believe that there was liquid water on Meridiani Planum in the past.

German-American seismologist Beno Gutenberg dies

He was interested in earthquakes. He was a collaborator Charles Richter in developing the Richter magnitude scale. Gutenberg invented the relationship between seismic magnitude and energy. He also co-discovered the Gutenberg–Richter law, which provides probability distribution of earthquakes for a given energy.

Japanese physician and bacteriologist Kiyoshi Shiga dies

He became famous for the discovery of Shigella dysenteriae, the bacillus causing dysentery. He identified it in 1897, during a severe epidemic in which more than 90,000 cases were reported, with a mortality rate approaching 30%. The bacterium Shigella was thus named after him, as well as the Shiga toxin, which is produced by the bacterium.

1st US city to fluoridate its water

It was Grand Rapids in Michigan. Main purpose of controlled addition of fluoride to a public water supply is to reduce tooth decay. The efficacy in children is proved, while in adults is less clear. Water fluoridation In the United states were proposed by a group of scientist led by H. Trendley Dean. They claimed that fluoride concentration of about 1 mg/L was associated with substantially fewer tooth cavities.

1st nuclear fission experiment in US

The experiment took place at the Columbia University, New York. Some of the investigators were Enrico Fermi, John Dunning or Francis G. Slack. Their work later led to the construction of Chicago Pile-1, the world's first artificial nuclear reactor. In 1942 it achieved self-sustaining nuclear chain reaction.

Belgian physical chemist Ilja Prigogine is born

He is noted for his work on dissipative structures. Dissipative structure is a thermodynamically open system which is operating out of, and often far from, thermodynamic equilibrium in an environment with which it exchanges energy and matter. The systems studied by Prigogine were somewhat similar to the living cells, although they were inanimate.

Russian-American geneticist Theodosius Dobzhansky is born

He was a central figure in the field of evolutionary biology for his work in shaping the so called modern synthesis. It was the reconciling Charles Darwin's theory of evolution and Gregor Mendel's ideas on heredity in a joint mathematical framework. Dobzhansky was born in Ukraine, then part of the Russian Empire, and became an immigrant to at 27.

British amateur mathematician William Shanks is born

He is famous for his calculation of π to 707 places, accomplished in 1873. His calculation was, however, only correct up to the first 527 places. The error was discovered in 1944 by D. F. Ferguson (using a mechanical desk calculator). Shanks also calculated other constants, like e, and published a table of primes up to 60 000.

Anniversaries of the (in)famous