In the following year Emanuel Lasker's patron, Krylenko, was purged by Stalin. Lasker tried to support himself by giving chess and bridge lectures and exhibitions, as he was now too old for serious competition. In 1940 he published his last book, "The community of the future", in which he proposed solutions for serious political problems, including anti-Semitism and unemployment. Lasker died of a kidney infection in New York on 11 January 1941, at the age of 72.
Viral hemorrhagic fever
Viral hemorrhagic fever is the name for a number of diseases. They often include fever and bleeding. They are caused by viruses. These fevers are one of the possible causes of the Black Death (most people think it is the bubonic plague).
Computer Algebra System
A computer algebra system (CAS) is a large computer program that helps people with mathematics and algebra. It changes and moves around (manipulates) mathematical equations and expressions containing numbers and symbols called variables. Variables can stand for known or unknown values that can be solved for, or can be replaced with any value. It always keeps the formula exactly the same mathematically as the original equation or expression, unless it is being transformed, by a transformation algorithm.
A CAS might be used for integration or differentiation (and other calculus transformations), simplification of an expression (making it smaller and/or simpler), optimizing and finding the minimum and maximum values of results or variables, etc. Most have the ability to plot functions and expressions for visualization, which can be helpful and educational too.
Computer algebra systems can be special purpose, focusing on only a few types of symbolic math, to very large, general purpose programs that do almost everything (for example, the free CAS Maxima, which is the oldest CAS that is still under development). The results output by a good computer algebra system are often exact, simple, and generalized to work in all possible cases. Computer programs do have bugs, so important results should always be verified for correctness.
Modern computer algebra systems often include extensive numeric capabilities for convenience and which fit together with its symbolic abilities.
Numeric domains supported often include real, complex, interval, rational, and algebraic numbers.
Usually floating point arithmetic is available to use if desired, because the arithmetic is done by most computer hardware very quickly. The down-side of floating point arithmetic is that it is not always exact, and is mostly useless for rocket science, because of only 14 decimal digits of accuracy (with double precision floats), and because of a growing round-off error with each calculation, sometimes even less digits are accurate. Rational number arithmetic is exact if all numbers are rational. Interval arithmetic can be used to easily calculate the total possible error of an inexact arithmetic system. Complex number arithmetic is generally supported by allowing the imaginary unit (formula_1) in expressions and following all of its algebraic rules.
Pi Day
Pi Day or Pie Approximation Day is a day when people around the world celebrate the number pi. They also eat pie to celebrate the pun as both words sound the same. Pi Day is held on March 14.
On Pi Day 2004, Daniel Tammet 22,514 decimal digits of π.
On March 14, 2010, Google made a sign celebrating Pi Day, with the word "Google" laid over images of circles and nothing else but pi symbols
Rick Hendrick
Joseph Riddick Hendrick III (born July 12, 1949) is the owner of the NASCAR race team Hendrick Motorsports. In the time that he has owned the team, he and his team have won ten Sprint Cup series championships.
A Key to Uncle Tom's Cabin
A Key to Uncle Tom's Cabin is a book written by Harriet Beecher Stowe, the writer of "Uncle Tom's Cabin". She was trying to show that the stories she wrote about slaves in "Uncle Tom's Cabin" were true. However, later studies showed that Stowe had actually read lots of the books she wrote about in "A Key to Uncle Tom's Cabin" after she had published her novel. It was first published in 1853 by Jewett, Proctor & Worthington.
Maru the cat
Maru the cat is a famous cat on the internet. He is from Japan and he is famous for sliding on his belly. A lot of people like to watch videos of Maru and look at pictures of him on his website. Maru also has a friend named Harry, who is a hedgehog.
Epistaxis
Epistaxis is when blood comes out of the nose. It is more commonly known as a nosebleed. Even though nosebleeds can seem scary, they are usually not serious or life threatening. Most nosebleeds happen in the front of the nose, and these are called "anterior nosebleeds". Sometimes, people get nosebleeds in the back of their noses, called "posterior nosebleeds". These are more serious, and somebody who has one may have to go to the hospital.
Nosebleeds are more frequent during the winter months. During this time, more upper respiratory infections occur and changes in temperature and humidity are larger.
Most nosebleeds are caused by one of the following:
They can also be caused by a reaction to something in the environment.
Many people tilt their heads back during a nosebleed, but this is actually not safe because it can make blood go down their throats and make them choke or get sick. Instead, the best way to deal with a nosebleed is to tilt one's head forward and pinch the bottom of their nose between one's nostrils with a wet piece of tissue paper.
Jeong Yak-yong
Jeong Yak-yong, also called Jeong Yag-yong, was a Korean philosopher in the Joseon Dynasty. He was also a thinker in the "Practical Learning", (silhak). Jeong Yak-yong was also one of the earliest Korean Catholic people.
Jeong was born, and died in Namyangju, Gyeonggi province.
Jeong served the government most of his whole life. He watched over the building of "Hwaseong Fortress" in Suwon in the 1790s. In 1794, he was the secret royal inspector (암행어사) of Gyeonggi province, and he checked and looked for the bad behaving officials. This later inspired his writings.
At different times in his life, Jeong had many kinds of "ho", or pen names. The most famous name was Dasan, which meant "tea mountain." Jeong used it while in his exile near a mountain of the same name, in Gangjin County, on the coast of South Jeolla province. Other pen names of his include Sammi (삼미/三眉), Yeoyudang (여유당/與猶堂), Saam (사암/俟菴), Jahadoin (자하도인/紫霞道人), Tagong (탁옹/籜翁), Taesu (태수/苔叟), Munamirin (문암일인/門巖逸人), and Cheolmasancho (철마산초/鐵馬山樵).
At birth, his father gave Jeong the name Gwinong, (귀농/歸農). Gwinong meant "returning to the land." As a Roman Catholic, Jeong had the baptized name John, or 요한 (Yohan), in Korean.
After his death, the King gave Jeong the special name Mundo (문도/文度). "Mun" meant writing or literature, and "do" meant law.
Silhak
Silhak (실학) was a teaching that was once very famous in the Joseun Dynasty, in Korea. "Sil" means "actual" or "practical," and "hak" means "studies" or "learning". It also meant "practical learning", like teaching how to farm and about economy.
Silhak was first made when the Joseon Dynasty was having a hard time, and after Japan had made war with them. The people of Korea were very poor, and their economical situation was not good. Also, all the farmland had grown and it was very hard to farm. To prevent all of this trouble, instead of learning neo-Confucianism, some philosophers decided that a new education should be made to help the poor, and they named it Silhak.
Southern corroboree frog
The southern corroboree frog ("Pseudophryne corroboree") is one of two species of corroboree frog ("Pseudophryne pengilleyi"). The other is the northern corroboree frog. The southern corroboree frog is a very small frog with warning colouration. It has black and yellow stripes, sometimes with a greenish tinge. It is one of the brightest frogs in the world.