Showing posts with label Knowledge. Show all posts
Showing posts with label Knowledge. Show all posts

Saturday, January 24, 2009

24 Solar Terms 二十四节气

The Chinese calendar is a lunisolar calendar that takes into account the movement of Sun and Moon. In a monthly basis, it follows the Moon's movement strictly while in a year basis, it follows the Sun's movement. That explains the reason for leap month after some time to correct the calendar.

The Chinese uses the Solar Terms (节气), which is a calendar of 24 periods and climate, to govern agricultural arrangements and functions in China. One of the significant similarity of Chinese calendar and Gregorian calendar is that both takes into account the longest (Summer Solstice) and the shortest days (Winter Solstice) of the year as well as two days eah year when the length of the day is equal to that of the night (Spring and Autumn Equinoxes).

During the Shang Dynasty, the Chinese had used only 4 solar terms. The number was increased to 8 during the Zhou Dynasty (11th century BC - 221BC). It was until the Western Han Dynasty (206BC - AD24) that the 24 terms were finally decided upon, which is the same as what it is today.

The 24 Solar Terms (二十四节气)


The date of Solar Terms are better described by the Gregorian Calendar as both follow the Sun's movement. However, there is a range of date for each terms as the Gregorian Calendar is not accurate on a year basis. (It has an error of around 6 hrs per year. That's why there is a leap day correction every 4 years and every 400 years)
Solar Terms节气MthDatesMeaning
Beginning of Spring立春Feb03 - 05Spring begins
Rain Water雨水Feb18 - 20It begins to rain
Waking of Insects惊蛰Mar05 - 07Hibernating animals come to sense
Spring Equinox春分Mar20 - 21Day and night are equally long. Mid Spring
Pure Brightness清明Apr04 - 06It is warm and bright
Grain Rain谷雨Apr19 - 21Rainfall is helpful to grain
Beginning of Summer立夏May05 -07Summer begins
Lesser Fullness of Grain小满May20 - 22Kernels plump
Grain in Beard芒种Jun05 - 07Wheat grows ripe
Summer Solstice夏至Jun21 - 22Longest daytime and shortest night
Lesser Heat小暑Jul06 - 08Torridity comes
Greater Heat大署Jul22 - 24Hottest moment of a year
Beginning of Autumn立秋Aug07 - 09Autumn begins
End of Heat处暑Aug22 -24Heat hides
White Dew白露Sep07 - 09Dew curdles
Autumn Equinox秋分Sep22 - 24Day and night are equally long. Mid Autumn
Cold Dew寒露Oct08 - 09Dew is very cold
Frost's Descent霜降Oct23 - 24Frost descends
Beginning of Winter立冬Nov07 - 08Winter begins
Lesser Snow 小雪Nov22 - 23It begins to snow
Greater Snow大雪Dec06 - 08It snows heavily
Winter Solstice冬至Dec21 - 23Shortest daytime and longest night
Lesser Cold小寒Jan05 - 07It is rather cold
Greater Cold大寒Jan20 - 21Coldest moment of a year


Two important Solar Terms to the Chinese are the Pure Brightness (清明) and Winter Solstice (冬至) which happen around 5th Apr and 22nd Dec on Gregorian Calendar each year respectively.

Saturday, November 29, 2008

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.

Friday, November 7, 2008

Presidents of the United States

S/NoPresident NameIn ServiceBornDiedAge at deathRemarks
1st
George Washington
30 Apr 1789 – 4 Mar 179722 Feb 173214 Dec 1799 67Led 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 180130 Oct 17354 Jul 182690Led a peaceful resolution of the Quasi-War crisis with France in 1798
3rd
Thomas Jefferson
4 Mar 1801 – 4 Mar 180913 Apr 17434 Jul 182683Promoted 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 181716 Mar 175128 Jun 183685Father of Constitution
5th
James Monroe
4 Mar 1817 – 4 Mar 182528 Apr 17584 Jul 183173Major 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 182911 Jul 1767 23 Feb 184880Proposed 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 183715 Mar 17678 Jun 184578Was 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 18415 Dec 1782 24 Jul 186279The Panic of 1837 resulted economic hardship causing him only able to serve one term.
9th
William Henry Harrison
4 Mar 1841 – 4 Apr 18419 Feb 17734 Apr 184168Served 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 184529 Mar 179018 Jan 186271

First President to obtain office by succession. Annexation of the Republic of Texas in 1845.

11th
James K. Polk
4 Mar 1845 – 4 Mar 18492 Nov 179515 Jun 184953Led 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 185024 Nov 17849 Jul 185065 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 18537 Jan 18008 Mar 187474Succeed Zachary Taylor after his death
14th
Franklin Pierce
4 Mar 1853 – 4 Mar 185723 Nov 18048 Oct 186964His 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 186123 Apr 1791 1 Jun 186877His 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 186512 Feb 180915 Apr 186556Led 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 186929 Dec 180831 Jul 187566Succeeded 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 187727 Apr 182223 Jul 188563Led 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 18814 Oct 182217 Jan 189370Losing 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 188119 Nov 183119 Sep 188149Second shortest presidency with his assassination 6 months after he became President.
21st
Chester Alan Arthur
19 Sep 1881 – 4 Mar 18855 Oct 182918 Nov 188657Facilitate the passage of the Pendleton Civil Service Reform Act
22nd
Stephen Grover Cleveland
4 Mar 1885 – 4 Mar 188918 Mar 183724 Jun 190871Only 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 189320 Aug 183313 Mar 190167Best 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 189718 Mar 183724 Jun 190871Only President to serve two non-consecutive terms. Was also the 22nd president.
25th
William McKinley, Jr.
4 Mar 1897 – 14 Sep 190129 Jan 184314 Sep 190158Fought 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 190927 Oct 1858 6 Jan 191960Negotiated 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 191315 Sep 18578 Mar 193072His 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 192128 Dec 18563 Feb 192467In 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 19232 Nov 18652 Aug 192357Signed 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 19294 Jul 18725 Jan 193360Elected 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 193310 Aug 187420 Oct 196490Tried 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 194530 Jan 188212 Apr 194563During 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 19538 May 188426 Dec 197288He 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 196114 Oct 189028 Mar 196978Oversaw 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 196329 May 191722 Nov 196346Was assassinated on November 22, 1963, in Dallas, Texas by Lee Harvey Oswald.
36th
Lyndon Baines Johnson
22 Nov 1963 – 20 Jan 196927 Aug 1908 22 Jan 197364His 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 19749 Jan 191322 Apr 199481His 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 197714 Jul 191326 Dec 200693Signed 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 19811 Oct 1924--Established a national energy policy that included conservation, price decontrol, and new technology.
40th
Ronald Reagan
20 Jan 1981 – 20 Jan 19896 Feb 19115 Jun 200493Implemented 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 199312 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 200119 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 20096 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 20094 Aug 1961---

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

Thursday, November 6, 2008

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

Saturday, October 11, 2008

Some interesting facts about our Moon

Some interesting facts about our Moon
1) Average period is about 29.5 days (it varies month to month)
2) Moon's orbit is almost completely circular
3) It takes around 50 mins later for the moon reach the same position as the day before (take 24 hr divide by 29.5)
4) Tide is resulted from Moon's gravitational pull (this increases Earth's biodiversity)
5) Our Moon is special as it is very large as compare to Earth (its formation is special as it results from a collision during Earth's early stage of formation - see http://www.psi.edu/projects/moon/moon.html for more info)
(This is important as it affects point 4)
6) Moon is around 4.5 billion years old
7) Moon's max orbit tilt is around 5 degree
8) Moon is around 0.38 million km away
9) Moon orbits Earth at a speed of 3,700 kilometers per hour
10) Moon travels a distance of 2.3 million km around the Earth
11) Moon's diameter is around 3,500 km
12) Maybe this is not obvious to some. Moon rises in the East and sets in the West
13) We are always looking at the same side of the Moon (no matter where you are on Earth)

Estimating Lunar Date in Singapore

I derive this simplified formula myself based on what I know (only works in Singapore - other areas have to use the other formulas)

Formula
Lunar date (estimated) = Time (1st 2 digits in 24 hr time) - 4 - Position of Moon from East
(+24 for negative value)

Lunar month (usually) = Gregorian Month - 1
(hence January is 12th month)

Terms:
Time:
take the first 2 digits of 24 hr time when you see the moon. Eg. If it is 11am, it is 11. If it is 7pm, it is 19
Number 4: It is constant (a correcting factor) (most other tropical countries will be 5)
Position of Moon from East: Direction East will be 0. Direction West will be 14. Directly above head will be 7. The rest is divided accordingly.

Please allow +-1 for estimated date of lunar date.

Examples

Example1: You see the moon at around 45 degree above ground in direction of East at 10pm in the month of May

Lunar date (estimated) = 22 - 4 - 4 = 16
Lunar month (usually) = 5 -1 = 4

So it is 16th of the 4th lunar month

Example 2: You see moon at around 10-20 degree above head to the direction of West at 9am in the morning in the month of december

Lunar date (estimated) = 9 - 4 - 8 = -3 = 21 (after adding 24)
Lunar month (usually) = 12 - 1 = 11

So it is 24th of the 11th lunar month

Please note that this is only an estimation as the position of moon depends a number of factors and it is not a constant. That is why some lunar holiday may change date as it gets closer.

Some affecting factors (there may be more)
1) Tilt of Moon's orbit with respect to the Earth
2) Location of Earth with respect to the Sun (Gravitation pull from the Sun is not constant as Earth's orbit is not completely circular)

Some Interesting Facts

  1. Human's brain stops growing in size at the age of about 15 years old
  2. Your body takes 48 hours to completely digest the food from one meal
  3. The nail on the thumb grows slowest while the nail on our middle finger grows fastest
  4. It is impossible to sneeze with both eyes open at the same time
  5. On aveage, we lose about 300g of weight while we are asleep at night
  6. You need less muscles to smile (around 15) than to frown (around 40)
  7. Bone is five times stronger than steel
  8. Women blink nearly twice as many as men
  9. Blind people who have been blind from birth cannot dream sights but they dream sounds instead
  10. Most dreams last only 5 to 20 minutes
  11. We die more quickly from lack of sleep than lack of food
  12. The sentence: "The quick brown fox jumps over the lazy dog" uses every letters of the alphabet
  13. Winston Churchill was born in a ladies' room during a dance
  14. ‘Dollar’ is the most common currency name, followed by ‘franc,’ ‘pound,’ ‘dinar,’ ‘peso,’ and ‘rupee’
  15. Venus is the only planet that rotates clockwise
  16. Penguins can convert salt water into fresh water
  17. Bats always turn left when exiting a cave
  18. Mosquitos are more attracted to the color blue than any other color
  19. Most cats are left pawed
  20. Crocodiles are unable to stick out their tongue
  21. A shark is the only fish that can blink with both eyes and can live up to 100 years
  22. Sharks fish by listening to their preys' heartbeats
  23. An ostrich's brain is smaller than its eye