Today in history

[dlbpharmd]

June 19

240 BC Eratosthenes estimates the circumference of Earth using two sticks.

1536 Anne Boleyn, Henry VIII's second wife, is beheaded.

1778 General George Washington's troops finally leave Valley Forge after a winter of training.

1821 The Ottomans defeat the Greeks at the Battle of Dragasani.

1846 The New York Knickerbocker Club plays the New York Club in the first baseball game at Elysian Field, Hoboken, New Jersey.

1848 The first Women's Rights Convention convenes in Seneca Falls, New York.

1861 Virginians, in what will soon be West Virginia, elect Francis Pierpoint as their provisional governor.

1862 President Abraham Lincoln outlines his Emancipation Proclamation. News of the document reaches the South.

1864 The USS Kearsarge sinks the CSS Alabama off of Cherbourg, France.

1867 Mexican Emperor Maximillian is executed.

1885 The Statue of Liberty arrives in New York City from France.

1903 The young school teacher, Benito Mussolini, is placed under investigation by police in Bern, Switzerland.

1919 Mustafa Kemal founds the Turkish National Congress at Ankara and denounces the Treaty of Versailles.

1933 France grants Leon Trotsky political asylum.

1934 The National Archives and Records Administration is established.

1937 The town of Bilbao, Spain, falls to the Nationalist forces.

1942 Prime Minister Winston Churchill arrives in Washington D.C. to discuss the invasion of North Africa with President Roosevelt.

1944 U.S. Navy carrier-based planes shatter the remaining Japanese carrier forces in the Battle of the Marianas.

1951 President Harry S. Truman signs the Universal Military Training and Service Act, which extends Selective Service until July 1, 1955 and lowers the draft age to 18.

1958 Nine entertainers refuse to answer a congressional committee's questions on communism.

1961 Kuwait regains complete independence from Britain.

1963 Soviet cosmonaut, Valentia Tereshkova, becomes the first woman in space.

1965 Air Marshall Nguyen Cao Ky becomes South Vietnam's youngest premier at age 34.

1968 Over 50,000 people march on Washington, D.C. to support the Poor People's Campaign.

1973 The Case-Church Amendment prevents further U.S. involvement in Southeast Asia.

1987 The U.S. Supreme Court voids the Louisiana law requiring schools to teach creationism.

1995 The Richmond Virginia Planning Commission approves plans to place a memorial statue of tennis professional Arthur Ashe.

[Waddley]

240 BC Eratosthenes estimates the circumference of Earth using two sticks.

I wonder how accurate his estimation was.

[Damelon]

240 BC Eratosthenes estimates the circumference of Earth using two sticks.

I wonder how accurate his estimation was.

Actually, he was only about 100 miles off. Though, I thought the experiment involved the difference in angle the sun went down a well at noon in two locations in Egypt

[iQuestor]

IIRC it was about 200 miles off. It did use shadows cast at noon in many different places.

The greeks continue to awe and inspire me, they were awesome.

[Waddley]

That is simply amazing. Wow.

Also- how do you say his name? I'm saying air-a-TOSS-thuh-nees but I'd imagine I'm not right.

[I'm Murrin]

According to Wikipedia:

Eratosthenes knew that on the summer solstice at local noon in the town of Syene on the Tropic of Cancer, the sun would appear at the zenith, directly overhead. He also knew, from measurement, that in his hometown of Alexandria, the angle of elevation of the Sun would be 1/50 of a full circle(7°12') south of the zenith at the same time. Assuming that Alexandria was due north of Syene he concluded that the distance from Alexandria to Syene must be 1/50 of the total circumference of the Earth. The distance between the cities was known from caravan travellings to be about 5000 stadia: approximately 800 km, or 500 miles. He established a final value of 700 stadia per degree, which implies a circumference of 252,000 stadia. The exact size of the stadion he used is no longer known; the common Attic stadion was about 185 m, which implies a circumference of 46620 km, i.e. 16% too large.

Although Eratosthenes' method was well founded, the accuracy of his calculation was inherently limited. The accuracy of Eratosthenes' measurement would have been reduced by the fact that Syene is not precisely on the Tropic of Cancer, is not directly south of Alexandria, and the Sun appears as a disk located at a finite distance from the Earth instead of as a point source of light at an infinite distance. There are other sources of experimental error: the greatest limitation to Eratosthenes' method was that, in antiquity, angles could only be measured to within about a quarter of a degree, and overland distance measurements were even less reliable. So the accuracy of the result of Eratosthenes' calculation is surprising.

...So now we have three different versions of it.


And apparently a later writer attributed a measurement of the distance between earth and sun to Eratosthenes--which was within 1% of the correct value.

[Damelon]

Here's an explanation by the man himself, Carl Sagan, from the series Cosmos regarding Eratosthenes experiment. Also, Wadds, he pronounces Eratosthenes.

www.youtube.com/watch?v=0JHEqBLG650&mod ... ed&search=

[Waddley]

Yeah, but that's Wikipeida, and that article doesn't cite it's sources.

According to what I looked up, Eratosthenes measured the earth as 250,000 stadia. One stadium (plural stadia) is argued to be about 600 feet-ish. So if we do a little math, that puts Era's estimation around 28,409 miles, when the actual measurement is 25,901.55 miles around the equator. Not THAT off, all things considered.

Now, exactly how long a stadium is isn't quite agreed upon. So if it's 157.2 meters, as Pliny suggests, then Era's measurement is a much more accurate 24,419.88 miles.

In case you were wondering.

Damelon- I can't watch videos at work. Also, I like my estimation. I'm going to pretend that Era measured the earth as 24,419.88 miles, because that's awesome.

[Damelon]

Wadds, a shame, you're missing a glimpse of a great series.

Era?

[Waddley]

Yeah, we're budds now. We've progressed beyond a first name basis, and are now on to nick names. He calls me melonhead.

(Also, I thought this was such an awesome topic that I mentioned it in my blog. Because because my peers need to know these kinda things. I drop the f-bomb, though. My peers like naughty language. It makes them feel all grown up.)

[Damelon]

Era probably used much the same language when he was explaining it.

[Waddley]

Yeah, Era can be a pretty shy guy but once you get to know him it's all curse words and loud gesticulative diatribes. The man is a riot.

[dlbpharmd]

June 20

451 Roman and barbarian warriors halt Attila's army at the Catalaunian Plains in eastern France.

1397 The Union of Kalmar unites Denmark, Sweden, and Norway under one monarch.

1756 Nearly 150 British soldiers are imprisoned in the 'Black Hole' cell of Calcutta. Most die.

1793 Eli Whitney applies for a cotton gin patent.

1819 The paddle-wheel steamship Savannah arrives in Liverpool, England, after a voyage of 27 days and 11 hours--the first steamship to successfully cross the Atlantic.

1837 18-year-old Victoria is crowned Queen of England.

1863 President Abraham Lincoln admits West Virginia into the Union as the 35th state.

1898 On the way to the Philippines to fight the Spanish, the U.S. Navy seizes the island of Guam.

1901 Charlotte M. Manye of South Africa becomes the first native African to graduate from an American University.

1910 Mexican President Porfirio Diaz proclaims martial law and arrests hundreds.

1920 Race riots in Chicago, Illinois leave two dead and many wounded.

1923 France announces it will seize the Rhineland to assist Germany in paying her war debts.

1941 The U.S. Army Air Force is established, replacing the Army Air Corps.

1955 The AFL and CIO agree to combine names for a merged group.

1963 The United States and the Soviet Union agree to establish a hot line between Washington and Moscow.

1964 General William Westmoreland succeeds General Paul Harkins as head of the U.S. forces in Vietnam.

1967 Boxing champion Muhammad Ali is convicted of refusing induction into the American armed services.

1972 President Richard Nixon names General Creigton Abrams as chairman of the Joint Chiefs of Staff.

1999 NATO declares an official end to its bombing campaign of Yugoslavia.

[dlbpharmd]

Here's an explanation by the man himself, Carl Sagan, from the series Cosmos regarding Eratosthenes experiment. Also, Wadds, he pronounces Eratosthenes.

www.youtube.com/watch?v=0JHEqBLG650&mod ... ed&search=

Great video! Sagan had a way with words, didn't he?

[Damelon]

He makes it so clear.

Had I been better at math in my school days, I'd probably be toiling on some astrophysical problem right now because of him.

[dlbpharmd]

He makes it so clear.

Had I been better at math in my school days, I'd probably be toiling on some astrophysical problem right now because of him.

Me too, not necessarily because of Sagan, just that I've always loved astronomy....but damn calculus is much too difficult.

[dlbpharmd]

June 21

217 BC Carthaginian forces led by Hannibal destroy a Roman army under consul Gaius Flaminicy in a battle at Lake Trasimenus in central Italy.

1314 The Scots, under Robert the Bruce, defeat Edward II's army at Bannockburn.

1377 Richard II, who is still a child, succeeds his grandfather, Edward III.

1667 The Peace of Breda ends the Second Anglo-Dutch War as the Dutch cede New Amsterdam to the English.

1675 Christopher Wren begins work on rebuilding St. Paul's Cathedral in London after the Great Fire.

1791 The French royal family is arrested in Varennes.

1834 C. H. McCormick patents the first practical reaper.

1862 Union and Confederate forces skirmish at the Chickahominy Creek.

1863 In the second day of fighting, Confederate troops fails to dislodge a Union force at the Battle of LaFourche Crossing.

1887 Britain celebrates the golden jubilee of Queen Victoria.

1900 General Arthur MacArthur offers amnesty to Filipinos rebelling against American rule.

1908 Mulai Hafid again proclaims himself the true sultan of Morocco.

1911 Porforio Diaz, the ex-president of Mexico, exiles himself to Paris.

1915 Germany uses poison gas for the first time in warfare in the Argonne Forest.

1919 Germans scuttle their own fleet at Scapa Flow, Scotland.

1939 Baseball legend Lou Gehrig is forced to quit baseball because of amyotrophic lateral sclerosis--a disease which wastes muscles.

1942 German General Erwin Rommel captures the port city of Tobruk in North Africa.

1945 Japanese forces on Okinawa surrender to American troops.

1948 Dr. Peter Goldmark demonstrates his "long-playing" record.

1958 A federal judge allows Little Rock, Arkansas to delay school integration.

1963 France announces it will withdraw from the NATO fleet in the North Atlantic.

1964 Three civil rights workers disappear in Meridian, Mississippi.

1982 John Hinkley Jr. is found not guilty by reason of insanity for attempting to assassinate President Ronald Reagan.

1995 The U.S. Senate votes against the nomination of Dr. Henry W. Foster for Surgeon General.

[dlbpharmd]

June 22

1558 The French take the French town of Thioville from the English.

1772 Slavery is outlawed in England.

1807 British seamen board the USS Chesapeake, a provocation leading to the War of 1812.

1864 Confederate General A. P. Hill turns back a Federal flanking movement at the Weldon Railroad near Petersburg, Virginia.

1876 General Alfred Terry sends Lieutenant Colonel George A. Custer to the Rosebud and Little Bighorn rivers to search for Indian villages.

1910 German bacteriologist Paul Ehrlich announces a definitive cure for syphilis.

1911 King George V of England crowned.

1915 Austro-German forces occupy Lemberg on the Eastern Front as the Russians retreat.

1925 France and Spain agree to join forces against Abd el Krim in Morocco.

1930 A son is born to Charles and Anne Morrow Lindbergh.

1933 Hitler bans political parties in Germany other than the Nazis.

1938 Joe Louis floors Max Schmeling in the first round of the heavyweight bout at Yankee Stadium.

1940 France and Germany sign an armistice at Compiegne, on terms dictated by the Nazis.

1941 Under the codename Barbarossa, Germany invades the Soviet Union.

1942 A Japanese submarine shells Fort Stevens at the mouth of the Columbia River.

1944 President Franklin Roosevelt signs the "GI Bill of Rights" to provide broad benefits for veterans of the war.

1956 The battle for Algiers begins as three buildings in Casbah are blown up.

1970 President Richard Nixon signs the 26th amendment, lowering the voting age to 18.

1973 Skylab astronauts splash down safely in the Pacific after a record 28 days in space.

1980 The Soviet Union announces a partial withdrawal of its forces from Afghanistan.

1981 Mark David Chapman pleads guilty to killing John Lennon.

1995 Nigeria's former military ruler Gen. Olusegun Obasanjo and his chief deputy are charged with conspiracy to overthrow Gen. Sami Abacha's military government.

[dlbpharmd]

June 23

1683 William Penn signs a friendship treaty with the Lenni Lenape Indians in Pennsylvania.

1700 Russia gives up its Black Sea fleet as part of a truce with the Ottoman Empire.

1758 British and Hanoverian armies defeat the French at Krefeld in Germany.

1760 Austrian forces defeat the Prussians at Landshut, Germany.

1848 A bloody insurrection of workers erupts in Paris.

1860 The U.S. Secret Service is created to arrest counterfeiters and protect the president.

1863 Confederate forces overwhelm a Union garrison at the Battle of Brasher City in Louisiana.

1865 Confederate General Stand Watie surrenders his army at Fort Towson, in the Oklahoma Territory.

1884 A Chinese Army defeats the French at Bacle, Indochina.

1885 Former general and president Ulysses S. Grant dies at the age of 63.

1902 Germany, Austria-Hungary and Italy renew the Triple Alliance for a 12-year duration.

1934 Italy gains the right to colonize Albania after defeating the country.

1944 In one of the largest air strikes of the war, the U.S. Fifteenth Air Force sends 761 bombers against the oil refineries at Ploesti, Romania.

1951 Soviet U.N. delegate Jacob Malik proposes cease-fire discussions in the Korean War.

1952 The U.S. Air Force bombs power plants on Yalu River, Korea.

1964 Henry Cabot Lodge resigns as the U.S. envoy to Vietnam and is succeeded by Maxwell Taylor.

1966 Civil Rights marchers in Mississippi are dispersed by tear gas.

[dlbpharmd]

June 24

1314 Scottish forces, led by Robert the Bruce, win an overwhelming victory against English King Edward II at the Battle of Bannockburn.

1340 The English fleet defeats the French fleet at Sluys, off the Flemish coast.

1497 Explorer John Cabot lands in North America in present-day Canada.

1509 Henry VIII is crowned King of England.

1664 The colony of New Jersey, named after the Isle of Jersey, is founded.

1647 Margaret Brent, demands a voice and a vote for herself in the Maryland colonial assembly.

1675 King Philip's War begins.

1812 Napoleon crosses the Nieman River and invades Russia.

1859 At the Battle of Solferino, also known as the Battle of the Three Sovereigns, the French army, led by Napoleon III, defeats the Austrian army under Franz Joseph I.

1861 Federal gunboats attack Confederate batteries at Mathias Point, Virginia.

1862 U.S. intervention saves the British and French at the Dagu forts in China.

1896 Booker T. Washington becomes the first African American to receive an honorary MA degree from Howard University.

1910 The Japanese army invades Korea.

1913 Greece and Serbia annul their alliance with Bulgaria following border disputes over Macedonia and Thrace.

1931 The Soviet Union and Afghanistan sign a treaty of neutrality.

1940 France signs an armistice with Italy.

1941 President Franklin Roosevelt pledges all possible support to the Soviet Union.

1943 Royal Air Force Bombers hammer Muelheim, Germany, in a drive to cripple the Ruhr industrial base.

1948 The Soviet Union begins the Berlin Blockade, America responds with the Berlin Airlift.

1953 John F. Kennedy and Jacqueline Bouvier announce their engagement.

1955 Soviet MIG's down a U.S. Navy patrol plane over the Bering Strait.

1964 The Federal Trade Commission announces that, starting in 1965, cigarette makers must include warning labels about the harmful effects of smoking.

1970 The U.S. Senate votes overwhelmingly to repeal the Gulf of Tonkin Resolution