This time, let's leave medicine and think about the history of science and technology. The Hawaiian Islands, where we live, were discovered by Captain Cook of England in 1778. At that time, England was a maritime nation and sent ships all over the world. The location of the Hawaiian Islands was recorded on nautical charts. How did he know where he was? That's easy, isn't it? You might say, why not just check with a GPS? But wait a minute. This was Captain Cook's time. There was no such thing. So what happened?
In fact, knowing your position is the most basic of navigation techniques. To begin with, position information is expressed by longitude and latitude. On a map, the vertical line is longitude and the horizontal line is latitude. Of these, latitude is relatively easy. Find the North Star at night and find its angle from the horizon, and that value is the north latitude. This is how you can find the north latitude easily. Why this happens is a little complicated, but it can be understood with the basics of geometry learned in junior high school. Ships are not the only ones that use this method. When watching World War II movies, there are occasional scenes where navigators in long-range bombers measure the position of the North Star, but they are measuring their current flying position.
The problem was longitude. It had not been possible to measure it for a long time. However, it was only when accurate clocks were made that it became possible to measure longitude. It was developed in Great Britain, a great maritime nation. Britain has traditionally been strong in mathematics, and even today it is extremely strong in mathematics-related science and technology, which is one of its greatest strengths.
The position of the Greenwich Observatory in England is set as the standard longitude 0. The time when the sun reaches its highest position at this position is set as 12:00. If you move from there and measure the time when the sun reaches its highest position (local noon) at a location using the clock brought from England, you can calculate the longitude from the time difference. Well, in theory it's simple, but the problem is how accurate the clock is. At that time, the most accurate clock was a pendulum clock. At first, we recorded the error between the noon astronomical observation and the clock every day at Greenwich. Once we found it to be quite accurate and thought it would be fine, we had to put it on a ship and travel around the world to experiment how much error there was. Since the ship sways, we built multiple mechanisms using springs to offset the swaying, and carried the clock suspended in mid-air. There were no commercial ships that could take a leisurely trip around the world, so a Royal Navy ship was asked to put the clock on board. The naval captains protested that it was a nuisance, but the King ordered them to put the clocks on board. However, the British naval captains agreed to put the clocks on board, on the condition that they would fight if they encountered the enemy, since they were military personnel. However, in those days, there were enemies all over England, and they were constantly engaged in combat. When they finally returned to Greenwich after completing their round-the-world tour, the clocks were significantly slower.
Apparently, when naval ships fight, they make sharp turns. The centrifugal force that occurs at that time seems to cause the clock to go out of sync. It was finally realized that there was a limit to pendulum clocks. So the British made a completely new clock. It was a clockwork clock. A clockwork clock is not affected by swings or centrifugal force like a pendulum. Moreover, it can be made much smaller in size. This seemed to work, so a second experiment was made to sail around the world. It was still a naval ship that held the experimental clock. As usual, the ship experienced frequent battles. As it neared the end of its voyage around the world, an island was visible ahead. The captain and his crew looked at the nautical chart and determined that this was an island occupied by their allies. However, the engineer who was experimenting with the clock warned them that it was an enemy island. The naval officers laughed and said, "Stop joking, we are professional navigators who have been at sea all our lives, our judgment was correct," However, as they approached the island, the ship was subjected to heavy shelling from the island and they were forced to escape for their lives. Since then, the British Navy has looked up to watchmakers. When the around-the-world experiment was completed, there was almost no time error. Thus, the technology to know the exact current position on the sea made voyages safer. In the 1760s, Britain produced 800 excellent Chronometers and equipped them on about 200 naval ships. Ten years later, Captain Cook discovered the Hawaiian Islands with a watch. Advances in watches supported Britain's maritime hegemony.
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