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Transcript of Work done by : Yitong Wang [email protected] Sophia Yiu [email protected] Gaohong Liu [email protected]...
Work done by :Yitong Wang [email protected] Yiu [email protected] Liu [email protected] Zhou [email protected]
Project 1 Physics 001 Section 001
The Invention, History and Impact of Compass
The Area of navigation is dark and cloudy!
People can’t go far without compass and nearly know nothing about the world outside.
Before compass’s invention, people use cordierite to determine the sun's direction and some lagging methods to determine four basic directions.
Before the Invention of Compass---
Compass is used to determine position of a
simple instrument. Formerly known as Sinan. The
main components are mounted on a shaft can freely
rotate the needle (commonly known as magnet).
Needle on the ground magnetic field can be
maintained at the tangent magnetic radial direction.
Needle points to the geographical North Pole South
Pole, take advantage of this performance can be a
sense of direction. Commonly used in navigation,
geodesy, travel and military and so on.
Introduction
The magnetic compass was first
invented as a device for divination as early as the
Chinese Han Dynasty (since about 206 BC), Formerly
known as Sinan. The compass was used in Song
Dynasty China by the military for navigational
orienteering by 1040-1044, and was used for maritime
navigation by 1111 to 1117. The use of a compass is
recorded in Western Europe between 1187 and 1202,
and in Persia in 1232. The dry compass was invented in
Europe around 1300. This was supplanted in the early
20th century by the liquid-filled magnetic compass.
(Wikipedia http://en.wikipedia.org/wiki/Compass#Using_a_compass)
Compass invented the ancient Chinese
practice of long-term understanding of the
results of magnetic objects. Ancient Chinese
people into contact with magnetite, as he
began to understand the nature of
magnetism. It cited the first to discover the
magnetic properties of iron. Then they
discovered that the directivity of the
magnet. After many experiments and
studies, and finally invented the compass
can be useful.
The Earth is also a big magnet, and its two
very near the geographic South Pole,
respectively, and the geographical North
Pole areas. Therefore, the Earth's surface
magnets, free to rotate, they will repel the
same sex due to magnet, opposites attract
nature of the north-south direction. This
principle is not enough to understand the
ancients, but such phenomena they are
very clear.
The working Principle of SINAN
A working model of the oldest instrument in the world
which is known to be a compass. The spoon or ladle is of
magnetic lodestone, and the plate is of Bronze. The
circular center represents Heaven, and the square plate
represents Earth . The handle of the spoon points south.
The spoon is a symbolic representation of the Great Bear.
The plate bears Chinese characters which denote the eight
main directions of north, north-east, east, etc., and
symbols from the I Ching oracle books which were
correlated with directions. Separately marked are the finer
gradations of twenty-four compass points, and along the
outermost edge are the twenty-eight lunar mansions. This
type of compass has been scientifically tested and found
to work tolerably well - It was used not for navigation, but
for quasi- magical purposes.(ORACLE Think Quest
http://library.thinkquest.org/23062/compass.html)
The Working Principle of magnetic compass
In ancient times, the sailors who used a magnetic compass to
navigate, believed that a group of stars or a mysterious range of
iron capped mountains in the north regulate its working. In China,
the magnetized iron found in the lodestone, a naturally occurring
magnetic ore was used to make a floating compass in the
12th century. A piece of magnetized iron placed on a wooden
splinter and floated in a bowl of water would itself swing to north-
south direction. A small pocket compass works on the same
principle as the first crude compass: instead of a lodestone and a
wood splinter, it has magnetized needle that swings on a pivot to
indicate north. The compass works because earth itself is a huge
magnet. Its magnetic poles are oval areas about 2100 Km from
the geographic north and south poles. The magnetic North Pole is
in Canada and the magnetic South Pole is near Antarctica.
Irregular lines of force connect the magnetic poles and the
compass needle simply aligns itself with these lines of force.
(http://www.abhigyan.com/TreasurePage/MagneticCompass.htm)
The invention of Compass certainly has some significant impacts on human’s world and society.
We concluded that there are basically four biggest impacts of compass.
1. Supporting Navigation, helping people discover the new continent
2. Used as building orientation
3. Supporting Mining
4. Supporting Astronomy
The Significant Impact of Compass
Prior to the introduction of the compass, position,
destination, and direction at sea were primarily determined
by the sighting of landmarks, supplemented with the
observation of the position of celestial bodies. On cloudy
days, the Vikings may have used cordierite to determine the
sun's direction and elevation from the polarization of
daylight; their astronomical knowledge was sufficient to let
them use this information to determine their proper
heading. For more southerly Europeans unacquainted with
this technique, the invention of the compass enabled the
determination of heading when the sky was overcast or
foggy. This enabled mariners to navigate safely far from
land, increasing sea trade, and contributing to the Age of
Discovery.(http://en.wikipedia.org/wiki/Compass#Using_a_compass)
Impact on Navigation
Evidence for the orientation of buildings by the means of
a magnetic compass can be found in 12th century
Denmark: one fourth of its 570 Romanesque churches are
rotated by 5-15 degrees clockwise from true east-west,
thus corresponding to the predominant magnetic
declination of the time of their construction. Most of
these churches were built in the 12th century, indicating
a fairly common usage of magnetic compasses in Europe
by then.
(http://en.wikipedia.org/wiki/Compass#Using_a_compass)
As Building Orientation
The use of a compass as a direction finder
underground was pioneered by the Tuscan
mining town Massa where floating magnetic
needles were employed for determining
tunneling and defining the claims of the
various mining companies as early as the 13th
century. In the second half of the 15th century,
the compass became standard equipment for
Tyrolian miners.
(http://en.wikipedia.org/wiki/Compass#Using_a_compas
s)
Impact on Mining
In the 14th century, the Syrian astronomer
and timekeeper Ibn al-Shatir (1304–1375)
invented a timekeeping device incorporating
both a universal sundial and a magnetic
compass. He invented it for the purpose of
finding the times of salat prayers. Arab
navigators also introduced the 32-point
compass rose during this time.
(http://en.wikipedia.org/wiki/Compass#Using_a_compass)
Impact on Astronomy
Knowing Your Way – Compass ORACLE Think Quest
http://library.thinkquest.org/23062/compass.html
Working Principle of a compass
http://www.abhigyan.com/TreasurePage/MagneticCompass.htm
Compass Wikipedia
http://en.wikipedia.org/wiki/Compass#Using_a_compass
Reference and Citations
Magnetic Compass Purple History
A short and interesting video introducing compass
Thank you!