The Ackermann function is an important example in mathematics of the
theory of computation. It is a recursive function which takes two
natural numbers as arguments and returns a natural number as its
value. In 1928, Wilhelm Ackermann considered a function A (m, n, p)
of three variables, the p-fold iterated exponentiation of m with n or
m → n → p in Conway's notation. He proved that it is a recursive
function which is not primitive recursive. This definition was later
simplified by Rozsa Peter and Raphael Robinson to the two-variable
definition given above. It grows extremely fast – this extreme growth
can be exploited to show that the computable function f (n) = A(n, n)
grows faster than any primitive recursive function and is therefore
not primitive recursive. Due to its definition in terms of extremely
deep recursion, it can be used as a benchmark of a compiler's ability
to optimize recursion.
Read the rest of this article:
http://en.wikipedia.org/wiki/Ackermann_function
Today's selected anniversaries:
1664 In the Second Anglo-Dutch War, the Netherlands surrendered
to England a fortified settlement in the New Netherland
colony known as New Amsterdam, which would eventually
become New York City.
(http://en.wikipedia.org/wiki/New_Amsterdam)
1841 Sultan of Brunei granted Sarawak to British adventurer
James Brooke, who subsequently became the Rajah.
(http://en.wikipedia.org/wiki/Sarawak)
1869 "Black Friday": Gold prices plummeted as a group of
speculators, headed by Jay Gould and James Fisk, plotted
but failed to control the market.
(http://en.wikipedia.org/wiki/Black_Friday_%281869%29)
1948 Soichiro Honda founded the Honda Motor Co., Ltd. and began
manufacturing motorcycles.
(http://en.wikipedia.org/wiki/Honda)
Wikiquote of the day:
"Goodness alone is never enough. A hard cold wisdom is required,
too, for goodness to accomplish good. Goodness without wisdom
invariably accomplishes evil." ~ Robert Heinlein in Stranger in a
Strange Land
(http://en.wikiquote.org/wiki/Stranger_in_a_Strange_Land)
A black hole is a theoretical concentration of mass with a
gravitational field so strong that its escape velocity exceeds the
speed of light. This implies that nothing, not even light, can escape
its gravity, hence the word "black." The term "black hole" is
widespread, even though the theory does not refer to any hole in the
usual sense. According to classical general relativity, no matter or
information can flow from the interior of a black hole to an outside
observer, although quantum mechanics may allow deviations from this
strict rule. The existence of black holes in the universe is well-
supported both theoretically and by astronomical observation;
however, a minority of physicists dissent.
Read the rest of this article:
http://en.wikipedia.org/wiki/Black_hole
Today's selected anniversaries:
1459 - The Battle of Blore Heath, the first major battle of the Wars
of the Roses, was fought at Blore Heath, in Staffordshire,
England. At least 3,000 men died.
(http://en.wikipedia.org/wiki/Battle_of_Blore_Heath)
1846 - Neptune, the eighth planet from the sun, was discovered by
French astronomer Urbain Jean Joseph Le Verrier, British
astronomer John Couch Adams and German astronomer Johann
Gottfried Galle.
(http://en.wikipedia.org/wiki/Neptune_%28planet%29)
1932 - Hejaz and Nejd were unified and became the Kingdom of Saudi
Arabia, with Abdul Aziz bin Abdul Rahman ibn Faisal Al Saud as
the first monarch and Riyadh as the capital city
(http://en.wikipedia.org/wiki/Saudi_Arabia)
Wikiquote of the day:
"At least two thirds of our miseries spring from human stupidity,
human malice and those great motivators and justifiers of malice
and stupidity, idealism, dogmatism and proselytizing zeal on behalf
of religious or political idols." ~ Aldous Huxley
(http://en.wikiquote.org/wiki/Aldous_Huxley)
The history of Irish theatre begins with the rise of the English
administration in Dublin at the start of the 17th century. In the
early days of its history, theatrical productions in Ireland tended
to serve the political purposes of the administration, but as more
theatres opened and the popular audience grew, a more diverse range
of entertainments were staged. Many Dublin-based theatres developed
links with their London equivalents and performers and productions
from the English capital frequently found their way to the Irish
stage. However, most Irish playwrights from William Congreve to
George Bernard Shaw found it necessary to go abroad to establish
themselves. At the beginning of the 20th century, theatres and
theatre companies dedicated to the staging of Irish plays and the
development of indigenous writers, directors and performers began to
emerge. This allowed many of the most significant Irish dramatists
to learn their trade and establish their reputations at home rather
than in Britain or the United States.
Reah the rest of this article:
http://en.wikipedia.org/wiki/Irish_theatre
Today's selected anniversaries:
1862 - The Emancipation Proclamation was issued by the Lincoln
administration.
http://en.wikipedia.org/wiki/Emancipation_Proclamation)
1869 - Richard Wagner's opera Das Rheingold debuted in Munich.
(http://en.wikipedia.org/wiki/Das_Rheingold)
1961 - Peace Corps was founded. Within two years, over 7,300 Peace
Corps volunteers were serving in 44 countries.
(http://en.wikipedia.org/wiki/Peace_Corps)
1980 - Iraq launched an invasion of Iran, starting the Iran-Iraq War.
(http://en.wikipedia.org/wiki/Iran-Iraq_War)
1989 - Famed American composer Irving Berlin died in his sleep at age 101.
(http://en.wikipedia.org/wiki/Irving_Berlin)
Wikiquote of the day:
"Human history becomes more and more a race between education and
catastrophe." ~ H. G. Wells
(http://en.wikiquote.org/wiki/H._G._Wells)
The Coronation of the British monarch is a ceremony in which the
monarch is formally crowned and invested with regalia. The coronation
usually takes place several months after the death of the previous
monarch, for the coronation is considered a joyous occasion that
would be inappropriate when mourning still continues. For example,
Elizabeth II was crowned on 1953-06-02, having ascended to the throne
on 1952-02-06. The ceremony is officiated by the Archbishop of
Canterbury, the most senior cleric of the Church of England. Many
other government officials and guests attend.
Read the rest of this article:
http://en.wikipedia.org/wiki/Coronation_of_the_British_monarch
Today's selected anniversaries:
1792 - French Revolution: The National Convention voted to abolish the
monarchy, and the First Republic was proclaimed.
(http://en.wikipedia.org/wiki/National_Convention)
1898 - The Hundred Days' Reform in China was abruptly terminated when
Empress Dowager Cixi forced the reform-minded Guangxu Emperor
into seclusion and took over the government as regent.
(http://en.wikipedia.org/wiki/Hundred_Days%27_Reform)
1937 - J. R. R. Tolkien's The Hobbit, a prequel to The Lord of the
Rings, was first published, with many black-and-white drawings
by Tolkien himself.
(http://en.wikipedia.org/wiki/The_Hobbit)
2003 - After 14 years of flight time and 8 years of service in the
Jovian system, Galileo spacecraft's mission was terminated by
sending the probe into Jupiter's atmosphere.
(http://en.wikipedia.org/wiki/Galileo_spacecraft)
Wikiquote of the day:
"What is done out of love always takes place beyond good and evil."
~ Friedrich Nietzsche in Beyond Good and Evil
(http://en.wikiquote.org/wiki/Beyond_Good_and_Evil)
The U.S. Electoral College is a specific form of an electoral college
and is the method by which the President and Vice President of the
United States are chosen. The Electoral College was established by
Article Two, Section One of the U.S. Constitution, and meets every
four years with electors from each state. The 23rd Amendment to the
Constitution has allowed electors from the District of Columbia to
cast votes for the election of the president. The electoral process
was modified in 1804 with the ratification of Amendment XII.
Presidential elections take place on the Tuesday after the first
Monday in November in years evenly divisible by four. Although
ballots typically list the names of the Presidential candidates,
voters within the 50 states and the District of Columbia actually
choose electors when they vote for President. These electors in turn
cast the official votes for President. Federal law says that each
state's electors meet in their state capitals on the Monday following
the second Wednesday of December. There, they cast their electoral
votes for President and Vice President.
Read the rest of this article:
http://en.wikipedia.org/wiki/U.S._Electoral_College
Today's selected anniversaries:
451 - Attila, king of the Huns, invaded Gaul, but was defeated by
Aetius with the help of Roman Foederati in the Battle of
Chalons.
(http://en.wikipedia.org/wiki/Battle_of_Chalons)
1378 - Papal Schism: Unhappy with the behavior of Pope Urban VI, a
group of cardinals elected a rival papacy in Antipope Clement
VII, throwing the Church into a turmoil.
(http://en.wikipedia.org/wiki/Western_Schism)
1854 - The Crimean War began with a Franco-British victory over
Russian forces at the Battle of Alma.
(http://en.wikipedia.org/wiki/Battle_of_Alma)
1946 - The first Cannes Film Festival began. Eleven films shared the
Palme d'Or that year.
(http://en.wikipedia.org/wiki/Cannes_Film_Festival)
1973 - Billie Jean King thrashed Bobby Riggs in straight sets before
30,492 spectators at the Astrodome in Houston, Texas in an
internationally televised tennis match dubbed as the "Battle
of the Sexes".
Wikiquote of the day:
"A saint is someone who has achieved a remote human possibility.
It is impossible to say what that possibility is. I think it has
something to do with the energy of love... Something in him so loves
the world that he gives himself to the laws of gravity and chance.
Far from flying with the angels, he traces with the fidelity of a
seismograph needle the state of the solid bloody landscape. His
house is dangerous and finite, but he is at home in the world. He
can love the shape of human beings, the fine and twisted shapes of
the heart. It is good to have among us such men, such balancing
monsters of love." ~ Leonard Cohen
(http://en.wikiquote.org/wiki/Leonard_Cohen)
Cricket is a team sport. The game, sometimes referred to as the
"gentleman's game," originated in its formal form in England, and is
popular mainly in the countries of the Commonwealth. In the countries
of South Asia, including India and Pakistan, cricket is by far the
most popular participatory and spectator sport. It is also the
national sport of Australia, and it is the major summer sport in New
Zealand, South Africa, and the United Kingdom. The rich jargon of
cricket can often leave those unfamiliar with the game confused; the
rules are of similar complexity to those of its cousin baseball.
Cricket fosters die-hard aficionados, for whom matches provide
passionate entertainment. Occasionally, rival nations have lampooned
each other over cricket matches, provoking diplomatic outrage.
Read the rest of this article:
http://en.wikipedia.org/wiki/Cricket
Today's selected anniversaries:
1356 - Despite a shortage of arrows, English forces led by Edward the
Black Prince decisively won the Battle of Poitiers and took
King Jean II of France as captive back to England.
(http://en.wikipedia.org/wiki/Battle_of_Poitiers)
1692 - Giles Corey, who had refused to enter a plea, was pressed to
his death during the Salem witch trials.
(http://en.wikipedia.org/wiki/Salem_witch_trials)
1893 - Women's suffrage: Women in New Zealand gained the right to
vote, as the country became the first to introduce universal
suffrage.
(http://en.wikipedia.org/wiki/Women%27s_suffrage)
1982 - Scott Fahlman proposed the use of the ASCII emoticons ":-)"
and ":-(".
(http://en.wikipedia.org/wiki/Emoticon)
1995 - The Unabomber's Manifesto was published in The Washington Post
and The New York Times, almost three months after it was
submitted.
(http://en.wikipedia.org/wiki/Theodore_Kaczynski)
Wikiquote of the day:
"The cardinal doctrine of a fanatic's creed is that his enemies are
the enemies of God." ~ Andrew Dickson White
(http://en.wikiquote.org/wiki/Andrew_Dickson_White)
The Tiananmen Square protests were a set of national protests in the
People's Republic of China, which occurred between 1989-04-15 and
1989-06-04, centered at Tiananmen Square in Beijing. The protests
were part of a conflict between the Chinese democracy movement and
the Communist Party of China. After several weeks, a decision was
made to forcibly remove the protesters. Entry of the troops into the
city was actively opposed by the citizens of Beijing, and an estimated
2,600 people died in the ensuing conflict. The suppression of the
protest was represented for many by the famous footage and photographs
of a lone protester, taken on June 5, standing in front of a column
of advancing tanks, halting their progress. The "tank man" continued
to stand defiantly in front of the tanks for half an hour before an
onlooker came over and pulled him away. Despite efforts, to this day
no one knows who the solitary figure was; TIME dubbed him "The
Unknown Rebel" and later named him one of the "100 Most Influential
People of the 20th Century."
Read the rest of this article:
http://en.wikipedia.org/wiki/Tiananmen_Square_protests_of_1989
Today's selected anniversaries:
96 - Nerva became Roman Emperor, ending the Flavian dynasty, and
the era of the Five Good Emperors began.
(http://en.wikipedia.org/wiki/Nerva)
1850 - United States Congress passed Fugitive Slave Act
(http://en.wikipedia.org/wiki/Fugitive_Slave_Law_of_1850)
1851 - New York Times began publishing.
(http://en.wikipedia.org/wiki/New_York_Times)
1895 - Daniel David Palmer made the first chiropractic adjustment.
(http://en.wikipedia.org/wiki/Daniel_David_Palmer)
1931 - The Mukden Incident: A section of a Japanese-built railroad
was allegedly destroyed by Chinese terrorists, providing an
excuse for the Japanese annexation of Manchuria.
(http://en.wikipedia.org/wiki/Mukden_Incident)
Wikiquote of the day:
"A faith is something you die for, a doctrine is something you kill
for. There is all the difference in the world." -- Tony Benn
(http://en.wikiquote.org/wiki/Tony_Benn)
In its pure form, glass is a transparent, relatively strong, hard-
wearing, essentially inert, and biologically inactive material which
can be formed with very smooth and impervious surfaces. These
desirable properties lead to the very many uses. Glass is, however,
brittle and will break into sharp shards. These properties can be
modified, or even changed entirely, with the addition of other
compounds. Glasses are uniform amorphous solid materials, usually
produced when a suitably viscous molten material cools very rapidly,
thereby not giving enough time for a regular crystal lattice to form.
Glasses can be made from many materials, although only a few
varieties are in common use. Common glass is mostly amorphous silicon
dioxide, which is the same chemical compound as quartz, or, in its
polycrystalline form, sand.
Read the rest of this article:
http://en.wikipedia.org/wiki/Glass
Today's selected anniversaries:
* 1787 - The text of the United States Constitution was finalized in
Philadelphia.
(http://en.wikipedia.org/wiki/United_States_Constitution)
* 1809 - The Treaty of Fredrikshamn concluded the Finnish War between
Russia and Sweden, and Finland became an autonomous Grand
Duchy under Czar Alexander I.
(http://en.wikipedia.org/wiki/Treaty_of_Fredrikshamn)
* 1894 - Japanese and Chinese navies clashed at Battle of Yalu River,
the largest naval engagement of the First Sino-Japanese War.
(http://en.wikipedia.org/wiki/Battle_of_Yalu_River_%281894%29)
* 1976 - The first Space Shuttle, Enterprise, was unveiled by NASA.
(http://en.wikipedia.org/wiki/Space_Shuttle)
* 1978 - The Camp David Accords were signed by Egyptian President
Anwar Sadat and Israeli Prime Minister Menachem Begin.
(http://en.wikipedia.org/wiki/Camp_David_Accords_%281978%29)
Wikiquote of the day:
"The mark of the immature man is that he wants to die nobly for a
cause, while the mark of a mature man is that he wants to live
humbly for one." -- Wilhelm Stekel
(http://en.wikiquote.org/wiki/Wilhelm_Stekel)
Lawrence v. Texas was a 2003 case decided by the United States
Supreme Court. In the 6-3 ruling, the justices invalidated the
criminal prohibition of homosexual sodomy in Texas. The court had
previously addressed the same issue in 1986 with Bowers v. Hardwick,
but there had upheld the challenged Georgia statute, not finding a
constitutional right to homosexual sodomy. Lawrence overturned
Bowers, which it held viewed the liberty at stake too narrowly. The
Lawrence court held that intimate consensual sexual conduct was part
of the liberty protected by substantive due process under the
Fourteenth Amendment. Lawrence had the effect of invalidating similar
laws throughout the United States insofar as they apply to consenting
adults acting in private. The case attracted much public attention,
and a large number of amicus curiae briefs were filed in the case.
The decision was celebrated by gay rights activists, hoping that
further legal advances may result as a consequence; the decision was
lamented by social conservatives for the same reasons
Read the rest of this article:
http://en.wikipedia.org/wiki/Lawrence_v._Texas
Today's selected anniversaries:
* 1597 - Twelve ships of the Korean navy led by Admiral Yi Sun-sin
sank 31 of 133 enemy ships and prevented a Japanese invasion.
(http://en.wikipedia.org/wiki/Yi_Sun-sin)
* 1701 - Prince James Francis Edward Stuart, more commonly referred
to as the "Old Pretender", became the Jacobite claimant of
the thrones of England and Scotland.
(http://en.wikipedia.org/wiki/James_Francis_Edward_Stuart)
* 1941 - Reza Pahlavi the Shah of Persia was forced to resign in
favor of his son, Mohammad Reza Pahlavi.
(http://en.wikipedia.org/wiki/Reza_Pahlavi)
* 1963 - Malaya, Singapore, North Borneo and Sarawak merged to form
Malaysia.
(http://en.wikipedia.org/wiki/Malaysia)
* 1982 - The Phalange, a Lebanese militia, carried out a massacre in
the Palestinian refugee camp of Sabra and Shatila.
(http://en.wikipedia.org/wiki/Sabra_and_Shatila_Massacre)
* 1992 - Black Wednesday: The British Pound Sterling was forced out
of the European Exchange Rate Mechanism and suffered a major
devaluation.
(http://en.wikipedia.org/wiki/Black_Wednesday)
Wikiquote of the day:
"The humbleness of a warrior is not the humbleness of the beggar.
The warrior lowers his head to no one, but at the same time, he
doesn't permit anyone to lower his head to him. The beggar, on the
other hand, falls to his knees at the drop of a hat and scrapes
the floor to anyone he deems to be higher; but at the same time, he
demands that someone lower than him scrape the floor for him."
~ Carlos Castaneda
(http://en.wikiquote.org/wiki/Carlos_Castaneda)
DNA repair is a constantly operating process in the cell essential
to survival because it protects the genome from damage. In human
cells, both normal metabolic activities and environmental factors
(such as UV rays) can cause DNA damage, resulting in as much as
500,000 individual molecular lesions per cell per day. These lesions
cause structural damage to the DNA molecule, and can dramatically
alter the cell's way of reading the information encoded in its genes.
Consequently, the DNA repair process must be constantly operating,
to rapidly correct any damage in the DNA structure.
Read the rest of this article:
http://en.wikipedia.org/wiki/DNA_repair
Today's selected anniversaries:
* 1821 - Costa Rica, Guatemala, Honduras, Nicaragua and El Salvador
proclaimed independence from Spain
* 1916 - Tanks, the "secret weapons" of the British Army during World
War I, were first used in combat at the Battle of the Somme.
(http://en.wikipedia.org/wiki/Battle_of_the_Somme_%281916%29)
* 1935 - Nazi Germany adopted the Nuremberg Laws, which deprived
German Jews of citizenship, and a new national flag with the
Swastika.
(http://en.wikipedia.org/wiki/Nuremberg_Laws)
* 1950 - Incheon Landing: United States forces landed at Incheon, Korea
(http://en.wikipedia.org/wiki/Korean_war#Inchon_Landing)
* 1952 - United Nations gave Eritrea to Ethiopia
(http://en.wikipedia.org/wiki/Eritrea)
* 1963 - A bomb exploded in the 16th Street Baptist Church, an
African-American church in Birmingham, Alabama, killing several
children.
(http://en.wikipedia.org/wiki/16th_Street_Baptist_Church_bombing)
Wikiquote of the day:
"We don't see things as they are, we see things as we are." ~ Anaïs Nin
(http://en.wikiquote.org/wiki/Ana%C3%AFs_Nin)