|
89 (number)
89 (eighty-nine) is the natural number following 88 and preceding 90. In mathematics 89 is: * the 24th prime number, following 83 and preceding 97. * a Chen prime. * a Pythagorean prime. * the smallest Sophie Germain prime to start a Cunningham chain of the first kind of six terms, . * an Eisenstein prime with no imaginary part and real part of the form . * a Fibonacci number and thus a Fibonacci prime as well. The first few digits of its reciprocal coincide with the Fibonacci sequence due to the identity ::\frac=\sum_^\infty=0.011235955\dots\ . * a Markov number, appearing in solutions to the Markov Diophantine equation with other odd-indexed Fibonacci numbers. ''M''89 is the 10th Mersenne prime. Although 89 is not a Lychrel number in base 10, it is unusual that it takes 24 iterations of the reverse and add process to reach a palindrome. Among the known non-Lychrel numbers in the first 10000 integers, no other number requires that many or more iterations. The palindrome r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinium
Actinium is a chemical element with the symbol Ac and atomic number 89. It was first isolated by Friedrich Oskar Giesel in 1902, who gave it the name ''emanium''; the element got its name by being wrongly identified with a substance André-Louis Debierne found in 1899 and called actinium. Actinium gave the name to the actinide series, a group of 15 similar elements between actinium and lawrencium in the periodic table. Together with polonium, radium, and radon, actinium was one of the first non-primordial radioactive elements to be isolated. A soft, silvery-white radioactive metal, actinium reacts rapidly with oxygen and moisture in air forming a white coating of actinium oxide that prevents further oxidation. As with most lanthanides and many actinides, actinium assumes oxidation state +3 in nearly all its chemical compounds. Actinium is found only in traces in uranium and thorium ores as the isotope 227Ac, which decays with a half-life of 21.772 years, predominantly e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
89 BC
__NOTOC__ Year 89 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Strabo and Cato (or, less frequently, year 665 ''Ab urbe condita'') and the Fourth Year of Zhenghe. The denomination 89 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Republic * Consuls: Gnaeus Pompeius Strabo and Lucius Porcius Cato. * Social War: ** Roman forces under Lucius Porcius Cato are defeated by the Italian rebels in the Battle of Fucine Lake, Cato is killed. ** The Roman army of Gnaeus Pompeius Strabo decisively defeats the rebels in the Battle of Asculum. * ''Lex Plautia Papiria'' extends citizenship to all Italians who applied for it within 60 days. The new citizens are enrolled in eight designated tribes, to prevent domination of the assemblies. * ''Lex Pompeia'' grants Latin rights to cities in Cisalpine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AD 89
AD 89 (LXXXIX) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Fulvus and Atratinus (or, less frequently, year 842 ''Ab urbe condita''). The denomination AD 89 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Europe * January 1 – Lucius Antonius Saturninus incites a revolt against Emperor Domitian (it is suppressed by January 24). * Legio XIII ''Gemina'' is transferred to Dacia, to help in the war against King Decebalus. * Aquincum (old Budapest, Óbuda) is founded (approximate date). Asia * First year of ''Yongyuan'' era of the Chinese Han Dynasty. * June – Battle of Ikh Bayan: The Han Chinese army under Dou Xian, allied with the southern Xiongnu, is victorious over the Northern Xiongnu. By topic Religion * Polycarpus I, G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1989
File:1989 Events Collage.png, From left, clockwise: The Cypress Street Viaduct, Cypress structure collapses as a result of the 1989 Loma Prieta earthquake, killing motorists below; The proposal document for the World Wide Web is submitted; The Exxon Valdez oil tanker runs aground in Prince William Sound, Alaska, causing a large Exxon Valdez oil spill, oil spill; The Fall of the Berlin Wall begins the downfall of Communism in Eastern Europe, and heralds German reunification; The United States United States invasion of Panama, invades Panama to depose Manuel Noriega; The Singing Revolution led to the independence of the Baltic states of Estonia, Latvia, and Lithuania from the Soviet Union; The stands of Hillsborough Stadium in Sheffield, Yorkshire, where the Hillsborough disaster occurred; 1989 Tiananmen Square protests and massacre, Students demonstrate in Tiananmen Square, Beijing; many are killed by forces of the Chinese Communist Party., 300x300px, thumb rect 0 0 200 200 1989 Loma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2089
In contemporary history, the third millennium of the anno Domini or Common Era in the Gregorian calendar is the current millennium spanning the years 2001 to 3000 ( 21st to 30th centuries). Ongoing futures studies seek to understand what is likely to continue and what could plausibly change in the course of this period and beyond. Predictions and forecasts not included on this timeline * List of future astronomical events ** List of lunar eclipses in the 21st century ** List of solar eclipses in the 21st century * Projections of population growth * Climate change ** Representative Concentration Pathway ** Shared Socioeconomic Pathways * Extinction * List of dates predicted for apocalyptic events * Predictions and claims for the Second Coming * Near future in fiction * Works falling into the public domain in the United States 21st century 2000s * See: 2001 * 2002 * 2003 * 2004 * 2005 * 2006 * 2007 * 2008 * 2009 2010s * See: 2010 * 2011 * 2012 * 2013 * 2014 * 2015 * 201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
