How crazy was liu hui, a mathematician 1,800 years ago?
Not only measured the height of Mount Tarzan, but also almost measured the weight of Tarzan?
"The gate of heaven roars for a long time, and the breeze comes from thousands of miles", "Will be the top of the mountain, overlooking the mountains and small" is to praise the tallness of Mount Tai.
"The weight of Mount Tai is a stone and nine dings", "the majesty of Mount Tai", and "An ru Taishan" are the expressions of Taishan's stability.
Photo: Tarzan Pole Top Stone, new and old photos contrast
From ancient times to the present, many people will invariably ask: "How high is Mount Tai?" How heavy is Tarzan? ”
Similarly, from ancient times to the present, many people have tried to measure Mount Tai. The famous mathematician Liu Hui did two things alone: first the first person recorded in the historical record to measure Mount Tai, and at the same time a rare person who weighed Mount Tai.
Let's take a look at the history of the measurement of Tarzan's height.
• In the fourth year of Jing Yuan (263), when Liu Hui's Annotation of the Nine Chapters of Arithmetic, the height of Mount Tai was equivalent to 1820 meters above sea level today.
• In the thirty-ninth year of the Wanli Calendar (1611), Zhang Wudian, a senator of the Shandong Provincial Department of Political Affairs, measured the height of Mount Tai as 1482.23 meters.
• In the fifty-ninth year of Qianlong (1794), The Shandong scholar Ruan Yuan measured Taishan as "one of the 477 inches and 9 inches and 31 inches taller than the (Tai'an) Examination Institute".
• In 1936, the team of Zhu Kezhen, director of the Central Meteorological Research Institute, measured the height of Mount Tai at an altitude of 1541.5 meters.
Behind every Tarzan measurement is a wonderful story.
Picture: The height of Mount Tai, the "Five Peaks Of Supremacy" of Mount Tai "head up to the sky"
Today we talk about the story of Liu Hui's measurement of Mount Tai and the weighing of Mount Tai.
Liu Hui (c. 225–295 CE), a native of Linzi during the Wei and Jin dynasties, was an underrated and great mathematician. His masterpieces "Notes on the Nine Chapters of Arithmetic" and "The Book of Island Arithmetic" are china's precious mathematical heritage, and Liu Hui's "circle cutting method" solves the deeds of pi and the weight difference measuring the height of Mount Taishan, which has preserved the mathematical history.
Figure: Liu Hui was the first person to correctly calculate pi, using the circumcision technique to find pi π = 3.1416
When it comes to pi, everyone will think of Zu Chongzhi as the father of pi, and Liu Hui, who was two hundred years earlier, was the first person in the historical data to accurately calculate pi.
Liu Hui used the "circumcision technique" to start cutting the circle from the circle with a diameter of 2 feet to the regular hexagon, and then obtained the positive 12-sided shape, the positive 24-sided shape... in turn, and finally calculated the area of the positive 3072 side, and calculated the pi π = 3.1416.
Liu Hui's calculation method is recorded in detail, and the extent to which Zu Chongzhi refers to Liu Hui's "circle cutting method" has become an unsolved mystery.
Another feat of Liu Hui was to measure the height of Mount Tai.
In the "Island Arithmetic Classic", Liu Hui carefully recorded the principle of using weight difference measurement, believing that the corresponding sides of similar right triangles grew proportionally, and then used the method of measuring the height and long depth to obtain the height of Mount Tai for 4 miles and 55 steps, which was converted to the current height of 1820 meters. While the actual altitude of Mount Tai is 1532 meters, the wisdom of the ancients is amazing.
Figure: The weight difference measurement method recorded in detail in the "Island Arithmetic Classic"
Another feat of Liu Hui was to weigh Mount Tai, although he was defeated.
Liu Hui also tried to measure the weight of Mount Tai: seeIng Mount Tai as a cone, he first used Pi to calculate the ground area of Mount Tai, plus the height of Mount Tai measured by himself, and the basic volume of Mount Tai could be obtained. Then take the unit weight of a Tarzan stone and multiply it to calculate the total weight of Tarzan.
However, the weight of Mount Tai was too large, and Liu Hui measured alone, and the conditions were simple, not only sighed: "Thousands of feet high, thousands of miles, unknowable", and finally failed to give up measurement.