A verst (Russian: верста, versta) is an obsolete Russian unit of length defined as 500 sazhen. This makes a verst equal to 1.0668 kilometres (0.6629 miles; 3,500 feet). == Plurals and variants == In the English language, verst is singular with the normal plural versts. In Russian, the nominative singular is versta, but the form usually used with numbers is genitive plural verst – 10 verst, 25 verst, etc. – whence the English form. "Verst" is sometimes used in Russian colloquial speech as a synonym for a kilometer. A mezhevaya versta (Russian: межевая верста, literally border verst) is twice as...

A native system of weights and measures was used in Imperial Russia and after the Russian Revolution, but it was abandoned after 21 July 1925, when the Soviet Union adopted the metric system, per the order of the Council of People's Commissars. The Tatar system is very similar to the Russian one, but some names are different. The Polish system is also very close to the Russian. The system existed since ancient Rus', but under Peter the Great, the Russian units were redefined relative to the English system. Until Peter the Great the system also used Cyrillic numerals, and only in the 18th century...

In political science and popular discourse, the horseshoe theory asserts that the far-left and the far-right, rather than being at opposite and opposing ends of a linear political continuum, closely resemble one another, analogous to the way that the opposite ends of a horseshoe are close together. The theory is attributed to French philosopher and writer Jean-Pierre Faye. Proponents of the theory point to a number of similarities between the far-left and the far-right, including their supposed propensity to gravitate to authoritarianism or totalitarianism. However, the horseshoe theory has also...

Ringwoodite is a high-pressure phase of Mg2SiO4 (magnesium silicate) formed at high temperatures and pressures of the Earth's mantle between 525 and 660 km (326 and 410 mi) depth. It may also contain iron and hydrogen. It is polymorphous with the olivine phase forsterite (a magnesium iron silicate). Ringwoodite is notable for being able to contain hydroxide ions (oxygen and hydrogen atoms bound together) within its structure. In this case two hydroxide ions usually take the place of a magnesium ion and two oxide ions.Combined with evidence of its occurrence deep in the Earth's mantle, this suggests...

Journey to the Center of the Earth (French: Voyage au centre de la Terre), also translated with the variant titles A Journey to the Centre of the Earth and A Journey into the Interior of the Earth), is a classic science fiction novel by Jules Verne. It was first published in French in 1864, then reissued in 1867 in a revised and expanded edition. Professor Otto Lidenbrock is the tale's central figure, an eccentric German scientist who believes there are volcanic tubes that reach to the very center of the earth. He, his nephew Axel, and their Icelandic guide Hans rappel into Iceland's celebrated...