Advances in Time and Position Instruments
by Rit Nosotro
Change Over Time essay |
.Explain how navigational technology (astrolabes, sextants, GPS, etc.) has
developed within the context of expanding encounters and its impact upon societies.
Time and position finders have been steadily changing over the centuries.
Even today advances are being made on the tools that we use to find our way.
In ancient times some people used the sun, moon, stars and even birds to find
which direction they were moving. However, those ways are mostly things of the
past. In recent centuries people have been using tools like crossbars, astrolabes,
and sun disks to find their way and time during the day, many times while out-to
sea. Tools like sextants and working clocks became heroes of the sea, by preventing
the loss of numerous ships and thousands of lives. Today we have GPS's (Global
Positioning Satellite) can tell us exactly where we are. In fact, government
prevents them from being too accurate in the hands of the common consumer.
The most ancient seagoing peoples used wave patterns, cloud formations, bird
behavior, and celestial objects to track their progress in a process called
"dead reckoning". These were highly inaccurate though, and celestial
objects could only tell direction, not position. Such ancients as the Egyptians,
Aztecs, and other civilizations figured out semi-accurate ways of global positioning,
but much of that is not understood even today. These civilizations were not
known for their open sea voyage and stayed in the coastal waters. This enabled
them to recognize landmarks that told them where they were and to where they
were heading.
The invention of the sundial was made so to cast a shadow upon a certain number
or nook in order to tell the time of day. Sundials were used throughout history,
and even before recorded times. Though the sundials could be used for accurate
time keeping on a flat level surface facing the right direction, they were practically
useless onboard a rocking boat.
Next we enter the Age of Discovery. The European conquest of the Americas may
have been much different without devices to know time and position. Inventors
worked to perfect the pendulum, the crossbars, longitude, sextant, and a variety
of clocks including a sea-worthy clock. The pendulum was not used on a boat
because, like the sundial, it had to be on a flat stationary surface to work.
The most primitive version of the sextant was named "the crossbars. This
name derived from the two bars that were moved on a dial to find out what time
it was. This operated by pointing one end at the horizon and the other end at
the sun, you would then look at the dial and find what time it said it was.
This though, caused blindness after frequent use.
The first mechanical clocks were massive semi-accurate timekeepers. Through
the years more compact and more accurate clocks were developed. Longitude (a
measurement of east and west) could be reliably known with accurate timepieces.
The sextant was next invented as a way of telling time and thus finding a semi-accurate
measurement on where a ship was. England realized the need for ships to have
precision timekeeping when its naval flagship went way off course and was lost.
They then decided to offer a reward of 20,000 pounds to whoever could produce
a sea-worthy timekeeper. After four tries John Harrison came out with his accurate
sea-worthy clock, the Harrison-4. Clocks grew more versatile, compact and accurate.
Advances in science led to the development of satellites. From satellites,
GPS was born. Today a GPS position finder is capable of telling you your position
accurately up to about three feet from anywhere in the world. As first seen
in "Desert Storm", missiles can use GPS to pinpoint a target. Mountain
climbers can know their three-dimensional location with the addition of altitude.
Car thieves avoid autos with GPS chips. Some criminals are forced to wear GPS
devices that signal authorities of parole violations. How might kidnapping became
a thing of the past? Technology continues to advance with time. Will ethical
practices in privacy be able to stay ahead of the technology? For our present
time, are we living in the future?
1. What was one of the listed ways ancients could tell their position?
A: Molds growing on rocks
B: Color of drinking water
C: Formations of birds
D: Tribal markings
2. What does GPS stand for?
A: Ground Publication Service
B: Global Positioning Satellite
C: Groups of Prehistoric Salamanders
D: Geometric Polygonal Surface
3. How much money was England offering in reward for the person that invented
a sea-worthy clock?
A: 5,000 US dollars
B: 10,000 pounds
C: 20,000 pounds
D: 1,000,000 US dollars
4. Who invented the first documented sea-worthy clock?
A: Albert Einstein
B: John Hopkins
C: John Harrison
D: Patrick Henry
1.C; 2.B; 3.C; 4.C
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