First black Mayor of Chicago

Harold Lee Washington was born on April 15, 1922, he  was an American lawyer and politician who became the first African-American Mayor of Chicago serving from 1983 until his death on November 25, 1987.

Johannes Stark - Stark effect

Johannes Stark was born on April 15, 1874, he was a German physicist, and Physics Nobel Prize laureate who was closely involved with the Deutsche Physik movement under the Nazi regime. He died on 21 June 1957. He discovered the Stark effect. It is the shifting and splitting of spectral lines of atoms and molecules due to presence of an external static electric field.

 

1st Olympic games close at Athens

The 1896 Summer Olympics, officially known as the Games of the I Olympiad, was a multi-spot event  held in Athens, Greece, from April 6 to April 15, 1896. It was the first international Olympic Games held in the Modern era.

Titanic Sank

RMS Titanic was a British passenger liner that sank in the North Atlantic Ocean on 15 April 1912 ( Hit an iceberg 11:40 pm (ship's time) 14 April 1912 on her maiden voyage and sank 2h 40m later) after colliding with an iceberg during her maiden voyage from from Southampton, UK to New York City ( US ).

Vishu - Equal

"Vishu" in Sanskrit means "equal". 

Vishu is a Hindu festival celebrated in the Indian state of Kerala and in the Tulunadu region(Mangalore & Udupi districts) usually in the second week of April in  the Gregorian calender .It marks the new year in accordance with Kolla varsham the Malayalam calendar. In 2013 Vishu is celebrated on April 14.

Christiaan Huygens

Christiaan Huygens was born on April 14, 1629, he was a prominent Dutch mathematician, astronomer, physicist and horologist. His work included early telescopic studies elucidating the nature of the rings of Saturn and the discovery of its moon Titan, the invention of the pendulum clock and other investigations in timekeeping, and studies of both optics  and the centrifugal force.Huygens achieved note for his argument that light consists of waves,now known as the Huygens-Fresnel principles.

Donald James Leslie

Donald James Leslie was born on April 13, 1911. He created and manufactured the Leslie speaker that refined the sound of the Hammond organ and helped popularize electronic music. He died on September 2, 2004.

First human spaceflight launched

The first human spaceflight was launched by the Soviet Union on April 12,1961 as a part of the Vostok program , with Cosmonaut Yuri Gagarin aboard.

International Labour Organization established

The International Labour Organization (ILO) was created by the 1919 Peace Conference that followed World War I. Its original constitution, which formed part of the Treaty of Versailles, established it on 11 April 1919 as an autonomous organization associated with the League of Nations.

Arnold Orville Beckman

 

Arnold Orville Beckman was born on April 10, 1900. He was an American chemist who invented a pH meter (1934) for measuring acidity and alkalinity and the quartz spectrophotometer, an instrument which pioneered automatic chemical analysis. He died on May 18, 2004.

Constitution of Pakistan created

The Constitution of the Islamic Republic of Pakistan is the supreme law of the State of Pakistan. Drafted by the government of Zulfikar Ali Bhutto, with an additionally assistance from the country's opposition parties, it was approved by the legislative assembly on April 10 and ratified on 14 August 1973.

Facebook purchases Instagram

Facebook purchases Instagram, a photo sharing application, for $1 billion April 9,2012.

Boeing 737 - First flight

The Boeing 737 made its first flight on April 9, 1967. It is a short- to medium-range twin-engine narrow-body jet airliner. Originally developed as a shorter, lower-cost twin-engine airliner derived from Boeing's707 and 727, the 737 has developed into a family of nine passenger models with a capacity of 85 to 215 passengers.

 

First female Prime Minister of Britain passed away

Margaret Hilda Thatcher, Baroness Thatcher, the first woman to become British prime minister, has died at the age of 87 on April 8,2013. She was a British politician, the longest-serving (1979–1990) Prime Minister of UK of the 20th century, and the only woman ever to have held the post and she was called the "Iron Lady" for her personal and political toughness.. She was born on 13 October 1925. 

Discovery Island opened & closed

Discovery Island is an 11.5 acres island  in Bay Lake at Walt Disney World in Bay Lake, Florida .

The island opened as Treasure Island on April 8, 1974, as a place to observe wildlife, and was later renamed Discovery Island when it was recognized as a zoological park. It closed to the public on April 8, 1999, but continued to operate until July 9, 1999.

World Health Organization established

World Health Organization (WHO) is a specialized agency of the UN that is concerned with international public health. It was established on 7 April 1948, with headquarters in Geneva , Switzerland, and is a member of the United Nations Development Group.

World Health Day

World Health Day is celebrated on 7 April to mark the anniversary of the founding of WHO in 1948. Each year a theme is selected for World Health Day that highlights a priority area of public health concern in the world. The theme for 2013 is high blood pressure

A solo voyage round the world.

Indian Navy officer Lt Commander Abhilash Tomy, The first Indian who embarked on a non-stop solo circumnavigation of the globe on a sail boat. He completes his voyage on April 6,2013.
He was the first Indian and the second Asian after Japanese Minoru Saito to attain the feat.

 

 

1st Modern Olympic games officially opens in Athens

The 1896 Summer Olympics, officially known as the Games of the I Olympiad, was a multi-spot event  held in Athens, Greece, from April 6 to 15, 1896. It was the first international Olympic Games held in the Modern era.

National Maritime Day of India

National Maritime Day of India falls on April 5. First celebrated on 5th April, 1964, the day marks the journey of SS Loyalty, the first ship of the Scindia Steam Navigation Company, to the United Kingdom.