Why is the sea blue?

Why is the sea blue?

The reason why the sea is blue has largely to with the theory of having a blue sky.

1) Sea reflects the colour from the sky

The water in the sea reflects and scatter the blue light from the sky that strikes on it, just like a mirror.

2) Sea refracts or scatters the light similar to the sky.

Since blue light has a shorter wavelength, it is refracted or scattered more than red light by the surface of water (or rather sea). Hence, we perceive sea as blue. Even if you are underwater, more blue light are scattered by the water molecules than red light and therefore the water appears blue.

Why is the sky blue? Why is sunrise and sunset red?

Why is the sky blue? Or rather, why does sky appear blue?

Before understanding that, you need to know that visible light is formed by 7 coloured lights, namely, red, orange, yellow, green, blue, indigo and violet (the colours of rainbow). In that order, red has the longest wavelength and lowest frequency with violet on the reverse.






When light passes throught our atmosphere during the day, it collides with oxygen and nitrogen in the air. Light with the shortest wavelength (blue and violet) are scattered more by the collision and hence the sky will appear more blue and violet. However, our eye is more sensitive to blue light than violet, therefore we perceive sky as blue.



Why is sunrise and sunset red or reddish in colour?



During sunrise and sunset, the light from the sun has to travel a greater distance through the atmosphere to reach our eye than during the day. You probably look at my ugly drawing below to understand. Red line is the distance travelled by light through the atmosphere during sunrise while blue line is the distance travelled by light during the day



As such, by the time the light reaches our eyes, much of blue light has already been scattered (the blue light may have been scattered more than twice), making red light the dominant colour. Hence, sunrise will appear more reddish in colour and gradually more yellowish. The reverse for sunset.

Presidents of the United States

S/No	President Name	In Service	Born	Died	Age at death	Remarks
1st	George Washington	30 Apr 1789 – 4 Mar 1797	22 Feb 1732	14 Dec 1799	67	Led the Continental Army to victory over the Kingdom of Great Britain in the American Revolutionary War (1775–1783)
2nd	John Adams	4 Mar 1797 – 4 Mar 1801	30 Oct 1735	4 Jul 1826	90	Led a peaceful resolution of the Quasi-War crisis with France in 1798
3rd	Thomas Jefferson	4 Mar 1801 – 4 Mar 1809	13 Apr 1743	4 Jul 1826	83	Promoted of the ideals of republicanism in the United States. Two major events during his presidency are the Louisiana Purchase (1803) and the Lewis and Clark Expedition (1804–1806).
4th	James Madison	4 Mar 1809 – 4 Mar 1817	16 Mar 1751	28 Jun 1836	85	Father of Constitution
5th	James Monroe	4 Mar 1817 – 4 Mar 1825	28 Apr 1758	4 Jul 1831	73	Major events include acquisition of Florida (1819), Missouri Compromise (1820), admission of Maine in 1820 as a free state, profession of the Monroe Doctrine (1823), declaring U.S. opposition to European interference in the Americas and breaking all ties with France remaining from the War of 1812.
6th	John Quincy Adams	4 Mar 1825 – 4 Mar 1829	11 Jul 1767	23 Feb 1848	80	Proposed a program of modernisation and educational advancement, but was stymied by Congress. Elected as a U.S. Representative from Massachusetts after leaving office and became a leading opponent of the Slave Power
7th	Andrew Jackson	4 Mar 1829 – 4 Mar 1837	15 Mar 1767	8 Jun 1845	78	Was the commander of the American forces at the Battle of New Orleans (1815), military governor of Florida (1821) and eponym of the era of Jacksonian democracy.
8th	Martin Van Buren	4 Mar 1837 – 4 Mar 1841	5 Dec 1782	24 Jul 1862	79	The Panic of 1837 resulted economic hardship causing him only able to serve one term.
9th	William Henry Harrison	4 Mar 1841 – 4 Apr 1841	9 Feb 1773	4 Apr 1841	68	Served 30 days in office, the shortest Presidency in United States' history, before his death in April 1841.
10th	John Tyler, Jr.	4 Apr 1841 – 4 Mar 1845	29 Mar 1790	18 Jan 1862	71	First President to obtain office by succession. Annexation of the Republic of Texas in 1845.
11th	James K. Polk	4 Mar 1845 – 4 Mar 1849	2 Nov 1795	15 Jun 1849	53	Led victory in the Mexican–American War and lowered the tariff and established a treasury system that lasted until 1913.
12th	Zachary Taylor	4 Mar 1849 – 9 Jul 1850	24 Nov 1784	9 Jul 1850	65	Urged settlers in New Mexico and California to bypass the territorial stage and draft constitutions for statehood, setting the stage for the Compromise of 1850. Died of acute gastroenteritis just 16 months into his term.
13th	Millard Fillmore	9 Jul 1850 – 4 Mar 1853	7 Jan 1800	8 Mar 1874	74	Succeed Zachary Taylor after his death
14th	Franklin Pierce	4 Mar 1853 – 4 Mar 1857	23 Nov 1804	8 Oct 1869	64	His popularity in the North declined sharply after he came out in favor of the Kansas-Nebraska Act, repealing the Missouri Compromise and reopening the question of the expansion of slavery in the West
15th	James Buchanan, Jr.	4 Mar 1857 – 4 Mar 1861	23 Apr 1791	1 Jun 1868	77	His unwillingness to begin the Civil War against the Southern states which declared their secession and inability to find a peaceful solution has subsequently been heavily criticised.
16th	Abraham Lincoln	4 Mar 1861 – 15 Apr 1865	12 Feb 1809	15 Apr 1865	56	Led the defeat of the secessionist Confederate States of America in the American Civil War. Abolised slavery and issued Emancipation Proclamation in 1863. Promoted the passage of the Thirteenth Amendment to the Constitution. Assassinated in 1865
17th	Andrew Johnson	15 Apr 1865 – 4 Mar 1869	29 Dec 1808	31 Jul 1875	66	Succeeded to the Presidency upon Lincoln's assassination on April 15, 1865. He also took charge of Presidential Reconstruction until 1866
18th	Ulysses S. Grant	4 Mar 1869 – 4 Mar 1877	27 Apr 1822	23 Jul 1885	63	Led Radical Reconstruction and built a powerful patronage-based Republican party in the South, with the adroit use of the army.
19th	Rutherford Birchard Hayes	4 Mar 1877 – 4 Mar 1881	4 Oct 1822	17 Jan 1893	70	Losing the popular vote to his opponent, Samuel Tilden, Hayes was the only president whose election was decided by a congressional commission.
20th	James Abram Garfield	4 Mar 1881 – 19 Sep 1881	19 Nov 1831	19 Sep 1881	49	Second shortest presidency with his assassination 6 months after he became President.
21st	Chester Alan Arthur	19 Sep 1881 – 4 Mar 1885	5 Oct 1829	18 Nov 1886	57	Facilitate the passage of the Pendleton Civil Service Reform Act
22nd	Stephen Grover Cleveland	4 Mar 1885 – 4 Mar 1889	18 Mar 1837	24 Jun 1908	71	Only President to serve two non-consecutive terms. Cleveland's admirers praise him for his honesty, independence, integrity, and commitment to the principles of classical liberalism
23rd	Benjamin Harrison	4 Mar 1889 – 4 Mar 1893	20 Aug 1833	13 Mar 1901	67	Best known for his economic legislation, including the McKinley Tariff and the Sherman Antitrust Act, and for annual federal spending that reached one billion dollars for the first time.
24th	Stephen Grover Cleveland	4 Mar 1893 – 4 Mar 1897	18 Mar 1837	24 Jun 1908	71	Only President to serve two non-consecutive terms. Was also the 22nd president.
25th	William McKinley, Jr.	4 Mar 1897 – 14 Sep 1901	29 Jan 1843	14 Sep 1901	58	Fought the Spanish-American War and annexed the Philippines, Puerto Rico, and Guam, as well as Hawaii, and set up a protectorate over Cuba. He was assassinated by Leon Czolgosz, an anarchist in 1901
26th	Theodore Roosevelt	14 Sep 1901 – 4 Mar 1909	27 Oct 1858	6 Jan 1919	60	Negotiated for the U.S. to take control of the Panama Canal as well as its construction in 1904. He was the first American to be awarded the Nobel Prize, winning its Peace Prize in 1906, for negotiating the peace in the Russo-Japanese War.
27th	William Howard Taft	4 Mar 1909 – 4 Mar 1913	15 Sep 1857	8 Mar 1930	72	His presidency was characterised by trust-busting, strengthening the Interstate Commerce Commission, expanding the civil service, establishing a better postal system, and promoting world peace.
28th	Thomas Woodrow Wilson	4 Mar 1913 – 4 Mar 1921	28 Dec 1856	3 Feb 1924	67	In April 1917, he asked Congress to declare war on the Central Powers. He went to Paris in 1919 to create the League of Nations and shape the Treaty of Versailles, with special attention on creating new nations out of defunct empires.
29th	Warren Gamaliel Harding	4 Mar 1921 – 2 Aug 1923	2 Nov 1865	2 Aug 1923	57	Signed peace treaties that built on the Treaty of Versailles (which formally ended World War I). He also led the way to world Naval disarmament at the Washington Naval Conference of 1921–22.
30th	John Calvin Coolidge, Jr.	2 Aug 1923 – 4 Mar 1929	4 Jul 1872	5 Jan 1933	60	Elected in his own right in 1924 where he gained a reputation as a small-government conservative.
31st	Herbert Clark Hoover	4 Mar 1929 – 4 Mar 1933	10 Aug 1874	20 Oct 1964	90	Tried to combat the Great Depression with volunteer efforts and government action, none of which produced economic recovery during his term.
32nd	Franklin Delano Roosevelt	4 Mar 1933 – 12 Apr 1945	30 Jan 1882	12 Apr 1945	63	During the Great Depression of the 1930s, Roosevelt created the New Deal to provide relief for the unemployed, recovery of the economy, and reform of the economic and banking systems. As Britain warred with Nazi Germany, Roosevelt provided Lend-Lease aid to Winston Churchill and the British war effort before America's entry into World War II in December, 1941. Elected to office for 4 terms (longest)
33rd	Harry S. Truman	12 Apr 1945 – 20 Jan 1953	8 May 1884	26 Dec 1972	88	He used executive orders to begin desegregation of the U.S. armed forces and to launch a system of loyalty checks to remove thousands of communist sympathizers from government office, even though he strongly opposed mandatory loyalty oaths for governmental employees
34th	Dwight David "Ike" Eisenhower	20 Jan 1953 – 20 Jan 1961	14 Oct 1890	28 Mar 1969	78	Oversaw the cease-fire of the Korean War, kept up the pressure on the Soviet Union during the Cold War, made nuclear weapons a higher defense priority, launched the Space Race, enlarged the Social Security program, and began the Interstate Highway System.
35th	John Fitzgerald "Jack" Kennedy	20 Jan 1961 – 22 Nov 1963	29 May 1917	22 Nov 1963	46	Was assassinated on November 22, 1963, in Dallas, Texas by Lee Harvey Oswald.
36th	Lyndon Baines Johnson	22 Nov 1963 – 20 Jan 1969	27 Aug 1908	22 Jan 1973	64	His popularity declined with events related to opposition to the Vietnam War. He died after suffering his third heart attack, on January 22, 1973.
37th	Richard Milhous Nixon	20 Jan 1969 – 9 Aug 1974	9 Jan 1913	22 Apr 1994	81	His foreign policy was marked by détente with the Soviet Union and rapprochement with the People's Republic of China. He successfully negotiated a ceasefire with North Vietnam, effectively ending American involvement in the Vietnam War. Nixon suffered a stroke on April 18, 1994 and died four days later, at the age of 81.
38th	Gerald Rudolph Ford, Jr.	9 Aug 1974 – 20 Jan 1977	14 Jul 1913	26 Dec 2006	93	Signed the Helsinki Accords, marking a move toward détente in the Cold War. The economy suffered from inflation and a recession during his tenure
39th	Jimmy Carter	20 Jan 1977 – 20 Jan 1981	1 Oct 1924	-	-	Established a national energy policy that included conservation, price decontrol, and new technology.
40th	Ronald Reagan	20 Jan 1981 – 20 Jan 1989	6 Feb 1911	5 Jun 2004	93	Implemented bold new political and economic initiatives. In his 1st term he survived an assassination attempt, took a hard line against organized labor, and ordered military actions in Grenada. His 2nd term was primarily marked by foreign matters, namely the ending of the Cold War, the bombing of Libya, and the revelation of the Iran-Contra affair.
41st	George H. W. Bush	20 Jan 1989 – 20 Jan 1993	12 Jun 1924	-	-	Operations were conducted in Panama and the Persian Gulf at a time of world change; the Berlin Wall fell in 1989 and the Soviet Union dissolved in 1991.
42nd	William Jefferson "Bill" Clinton	20 Jan 1993 – 20 Jan 2001	19 Aug 1946	-	-	Presided over the longest period of peace-time economic expansion in American history, which included a balanced budget and a reported federal surplus.
43rd	George W. Bush	20 Jan 2001 –20 Jan 2009	6 Jul 1946	-	-	Announced a global War on Terrorism in 2001 after terrorist attacks in 11 Sep 2001 and ordered an invasion of Afghanistan that same year. He also declared an invasion of Iraq in 2003.
44th	Barack Hussein Obama II	20 Jan 2009	4 Aug 1961	-	-	-

For ranking of U.S. president, please view wikipedia at http://en.wikipedia.org/wiki/Historical_rankings_of_United_States_Presidents

U.S. New President

Facts about Obama
Personal
1. His full name is Barack Hussein Obama II
2. He was born at Kapi'olani Medical Center for Women & Children in Honolulu, Hawaii on Aug 4, 1961
3. His mother's name is Stanley Ann Dunham (Caucasian) and his father's name is Barack Hussein Obama (African) (same name)
4. His parent separated in 1963 and divorced in 1964.
5. His mother then married to Lolo Soetoro, and the family moved to Indonesia in 1967
6. In 1971, Obama returned to Honolulu to stay with his maternal grandparents until 1979
7. In 1979, he moved to Los Angeles, where he studied at Occidental College for two years
8. In 1981, he moved to New York, where he majored in political science with a specialization in international relations in Columbia College.
9. His father died in a car crash in Nairobi in 1982 (Born: 1936. Died: 1982. Aged: 46)
10. In 1985, he moved to Chicago where he worked as the director of the Developing Communities Project (DCP) and a consultant and instructor for the Gamaliel Foundation
11. In 1988, he entered Harvard Law School
12. In June 1989, he first met his wife, Michelle L. Robinson, when he was employed as a summer associate at the Chicago law firm of Sidley Austin
13. He was married at the age of 31 with Michelle L. Robinson on 03 Oct 1992
14. His mother died of ovarian cancer in 1995 (Born: 29 Nov 1942. Died: 7 Nov 1995. Aged: 52)
15. Obama's religion is United Church of Christ and his church is Trinity United Church of Christ in Chicago, Illinois
16. He has two children, Malia Ann (born in 1998) and Sasha (born in 2001).

Family
Paternal grandfather:
Hussein Onyango Obama (1895-1979)

Paternal grandmother:
Habiba Akuma Obama (2nd wife of Hussein Onyango Obama)

Paternal step-grandmother:
Sarah Obama (born: 1922)

Step-mothers (His mother is the 2nd wife of his father):
Kezia Obama (born 1940) (1st wife of his father)
Ruth Ndesandjo (born 1940s) (3rd wife of his father)
Jael (4th wife of his father)


Parental half-brothers:
Malik Obama or Abongo or Roy (born Mar 1958) (his father with Kezia)
Abo Obama (born 1968) (his father with Kezia)
Bernard Obama (born 1970) (his father with Kezia)
Mark Ndesandjo (his father with Ruth)
David Ndesandjo (his father with Ruth) (killed in a motorcycle accident)
George Hussein Onyango Obama (born 1982) (his father with Jael)

Patental half-sister:
Auma Obama (born 1960. Spouse: Ian Manners. Child: Akinyi {born: 1997}) (his father with Kezia)

Maternal half-sister:
Maya Kassandra Soetoro-Ng (born: 15 Aug 1970. Spouse:Konrad Ng. Child: Suhaila Ng) (his mother with Lolo Soetoro)

Political
1. Obama is the first African-Amercian U.S. President
2. He is the 44th President of the United States
3. He was a State legislator from 1997 to 2004
4. He was elected to the Senate in November 2004
5. His inauguration as United States President will be on 20 Jan 2009


Links
Obama's Birth Certificate
Obama's Marriage Certificate