What was it like in ancient times?
In literature, the passage and irreversibility of time are repeatedly mentioned in ancient and modern China and abroad. Time flies, the sun and the moon fly like a shuttle. This idiom not only reflects the ancients' most direct understanding of time: day and night intersect, time intersects, but also reflects the ancients' understanding and feelings about the irreversibility of time.
"Yuan Shi Tian" contains: "The system of landscape symbols is lengthened with copper leaves, two inches for Bo and two inches for Bo. If the needle is mustard seed, the wetting side is a shackle, and one end is set as a machine shaft, it can be opened and closed, and the other end is stopped, so that it can be tilted, and it moves back and forth in the imaginary beam. It's like Xu Mi, you can see its light. "
In ancient China, the standard table was a tool to determine the seasons, divide the four seasons and calculate the calendar according to the change of the length of the sun shadow. Guibiao consists of "Gui" and "Biao", which is a pole or column standing vertically on the ground; Gui is a horizontal ruler perpendicular to a vertical pole or column on the ground, pointing to true north. At noon, the sun shadow of "Biao" falls on the scale of "Gui". According to the length of the sun shadow, we can calculate the solar terms and calculate the calendar. For example, the length of a year can be determined by measuring the time interval when the shadow length is the longest at noon (12) (the time interval between two winter solstice points). Determine the winter solstice and summer solstice by measuring the length of the noon shadow, and then calculate the length of the tropic year.
The high watch made in Guo Shoujing, China in Yuan Dynasty was designed to promote the development of standard watches.
In the past, there were several difficulties in using standard watches. First of all, the shadow edge is not clear. The closer the shadow is to the edge, the lighter the color is, and it is difficult to determine where the shadow ends. If the boundary of the shadow is not clear, the length of the shadow cannot be measured accurately. Secondly, the technique of measuring the shadow length is not accurate. In ancient times, the length of a ruler was generally only energy to minutes, which could be estimated to centimeters, that is, one tenth. According to the traditional method, the shadow length of winter solstice is measured. If there is a little error in the measurement, the calculated winter solstice time will have an error of one and a half hours. In ancient China, a day was divided into 12 hours, and one hour is equivalent to two hours as we say today. So this is a big mistake in the astronomical calendar. Finally, the standard can only observe the sun shadow, not the moon shadow and the star shadow.
Faced with these difficulties, scientists have thought of many ways since the Tang and Song Dynasties, but they have never solved them well. Guo Shoujing did not flinch in the face of difficulties. He started with the analysis of the reasons for the difficulties, and then looked for countermeasures for each reason to solve the difficulties one by one.
The "watch" of the previous generation of standard watches was only eight feet high, and the shadow was short and the edge was blurred, so the measurement was wrong and the actual error was great. The gauge designed by Guo Shoujing, called "high gauge", is to raise the gauge rod to 40 feet and increase it to 5 times, so the surface shadow during observation is also lengthened to 5 times. Compared with the shadow length, the error caused by unclear edge will reduce the proportion of shadow length, and the measured data will be much more accurate. According to this example, the error of calculating solar terms will be significantly reduced. In addition, erecting a beam at the top of the high table also helps to identify the edge of the shadow.
High table can't completely solve the problem of clear table shadow edge. Guo Shoujing then created an auxiliary instrument called "Jingfu" to improve the measurement effect. Scene symbols, that is, shadow symbols. It is a piece of copper four inches long and two inches wide with a pinhole in the middle. One end of the copper sheet is hinged to the edge of a two-inch square frame; The other end is supported by a small stick, which can be opened and closed freely like a box cover to adjust its inclination. Place the landscape symbol on the GUI surface. Facing the sun, the sun will pass through the small hole and hit the GUI surface, forming a very tiny image of the sun, which is very bright. When measuring the midday sun shadow, first place the landscape symbol next to the shadow end on the Gui surface so that it is perpendicular to the sunlight, and then move the landscape symbol back and forth so that the sun, the light beam at the top of the high table and the small hole on the symbol are in a straight line. As a result, the sun exposed on Guimian is as bright as a grain of rice, with a shadow as thin as a hair in the middle. Write down its position immediately, and you can measure the length of the shadow. This is a pinhole imaging method, which makes the virtual shadow cast by the high gauge beam become an accurate real image in the sun, and the measured surface shadow length is much more accurate than the previous standard gauge.
The hourglass is a kind of timing instrument, also called sand clock and sand jar. The hourglass usually consists of two connected quicksand pools, and the inside is sealed with certain quicksand according to the calculated time. In Japanese, it is quite appropriate to call it a sand timepiece.
In ancient China, it was found that water in porcelain regularly leaked from cracks. Therefore, the leaky carving was developed. After water (or mercury) is injected into a leaky pot with a small hole, it drops into another container-an arrow pot. Open a small hole in the cover of the arrow pot, insert an arrow shaft, engrave the time on the arrow shaft, and then hold it up with a driftwood, and you can know the approximate time.
Smart people know that the more water in a pot, the faster the flow rate, and the less water, the slower the flow rate. Knowing that it would affect the accuracy of timing, I added a leaky pot to the pot, and the water flowed first, so that the time was accurate.
According to the Liang Dynasty's Lost Engraving Classics, "The lost engraving was made on the day of Xuanyuan and was proclaimed as the generation of Xia and Shang Dynasties". This shows that as early as three or four thousand BC, during the patriarchal commune period, there was a phenomenon of rain leakage in China.
The five-wheel hourglass was successfully developed by Zhan Xiyuan in 1360. Ming An Youqi's Supplement to Natural History: "The five-wheel hourglass: the water in the north is good at freezing, and the pot does not leak. Xin 'an Zhanxi Yuan replaced water with sand. People think that ancient times did not exist. " To this end, Song Lian wrote an article "Inscription of the Five Wheels of the Hourglass".
The leaky pot is a kind of water clock, also called copper pot dripping water and copper dripping water. This is an ancient timer, usually made of bronze. Needham speculated that the clepsydra may have been introduced to China from Mesopotamia, possibly as early as the Zhou Dynasty in the second century BC, but not later than the first century BC. Found it in Liu Sheng's grave. Copper pots are mostly cylindrical, with a leak near the bottom, and a small hole on the lid with a wooden arrow or ruler engraved with degrees. When the kettle water flows out from the leaking spout, the wooden arrow will drop to indicate the time at that time.
Since the Western Han Dynasty, broken kettle wine has been gradually replaced by broken kettle wine, which is characterized by a broken arrow floating on the surface of the pot, indicating the time with the rise of the water surface.
In the Yuan Dynasty, the dripping of copper pot evolved into a stepped leaky pot. The pots cast by Xian Yun, a metallurgical worker in Guangzhou in Yuan Dynasty, are divided into four layers, which are Japanese pots, chamber pot pots, flat pots and receiving pots. Gradually contract from top to bottom. A copper ruler of 12 hour was erected in the bottom receiving kettle. Water drips from the highest daily tank to the bottom receiving tank from top to bottom. The floating arrow in the pot rises gradually, indicating the time, and the error is not big every day.
Besides water clocks, mechanical clocks and candle clocks, incense clocks are also used in the Far East. About the 6th century, incense bells were first used in China. In Masakura, Japan, there is still a fragrant bell, but the words on it are Sanskrit instead of Chinese. Because Sanskrit is often used in Buddhism, Edward Shafir speculated that incense bells were used in Buddhist ceremonies and were invented by Indians. The incense clock is similar to a candle clock, but it burns evenly and has no flame, so it is more accurate and safer than a candle clock when used indoors.
The first water clock using escapement was built in Chang 'an by a group of tantric monks and mathematicians and government official Liang Lingzan. This escapement water clock is an astronomical instrument. A row of escape clocks are still water clocks, so they will be affected by temperature changes. In 976, Zhang Sixun solved this problem. He replaced water with mercury, which was still liquid when the temperature dropped to MINUS 39 degrees Celsius (MINUS 38 degrees Fahrenheit).
In the first year of Yuan You (1086), when Su Song inspected the armillary sphere of Taishi Bureau, he was determined to combine the armillary sphere, the elephant and the timer into one. Su Song visited Han Gonglian, a senior official of the official department, and obtained The Outline of Instruments by Zhang Heng and Zhang Sixun. Yuan You started construction in the third year (1088), and Yuan You completed the "water transport instrument platform" in the seventh year (1092).
The image platform of the water carrier is similar to the observatory, with a height of about12m and a width of 7m, and is divided into three layers. The upper layer is the armillary sphere (used for astrometry), the middle layer is the armillary sphere (celestial operation demonstration), and the lower layer is the Chen Si (automatic timer). The whole process is driven by water power, which can accurately tell the time. Needham pointed out that this is the direct ancestor of the European astronomical clock. In the early years of Yu Shaosheng, Su Song wrote a book "Essentials of New Instrument Images", which introduced in detail the overall function of the water transport instrument image platform, more than 150 parts and more than 60 illustrations.
During the Jingkang (1 127) disaster, Jin Bing took the original water transport instrument to Yanjing and put it on the fourth roof. In the second year of Jin Dynasty (12 14), it was abandoned due to inconvenient transportation, but the manuscripts preserved in Xie Su in the Southern Song Dynasty could not be copied because no one knew the law.
China ancient incense burning alarm clock. In ancient China, besides using water to time, people also used burning incense to time. Dragon boat time is more fragrant, and it is an instrument for timing by burning incense. It also has the function of ringing the bell regularly. On the dragon boat, there are several small strings with metal balls tied at both ends, and incense is burned under the strings. Every once in a while, incense will burn a thread, and when the metal ball falls into the container below, it will ring a bell. This kind of incense burning timepiece was first seen in the literature of the Song Dynasty (65438+the middle of the 2nd century). It is not accurate to calculate the time with incense, but it used to be very popular because it is simple and easy to use, and it is very suitable for folk use. According to the literature, some of them are fragrant and can be burned for one night, while others can even be burned for one month. This fragrance is restored according to documents and drawings, and there is no original handed down.
1088, Su Song and Han Gonglian, scientists of the Song Dynasty, made the first aquatic instrument stage in history, which was composed of an armillary sphere, an elephant and a mechanical timer. It is driven by hydraulic power and has a scientific escapement mechanism. It is about 12 meters high and 7 meters square, and is divided into three layers: the upper layer is equipped with an armillary sphere for astronomical observation; The middle layer can simulate celestial bodies for synchronous demonstration; The lower layer is the heart of the instrument, and the formation and output of timing, time telling, power supply are all on this layer.
1276, Guo Shoujing of the Yuan Dynasty in China made a big leaky lamp. It is driven by water power, which drives the puppet to automatically say the time of "ring the bell for a while, carving the drum for two minutes, ringing the cymbals three times and ringing the cymbals four times" through a gear train and a rather complicated cam structure. Since the Song Dynasty, the 24-hour clock system started at 12, and one minute is today's 15 minutes, which is more than 300 years earlier than the German desk clock.
1283, the first mechanical clock driven by weight appeared in English monasteries.
Monks in northern Italy began to build bell towers (or bell towers) in the third century A.D./Kloc-to remind people of the time of prayer.
1360, Zhan Xiyuan created the "five-wheel hourglass", which consists of gears and a time disk. .
Lamp clock: Time is measured by oil lamp, and the time is indicated by the amount of remaining oil after combustion. Traditionally, in China, the dry stem pith of Juncus Junceae is used as twist.
Xiang Zhong: It's more convenient than an oil lamp. Cheap, convenient and practical, it was quite popular in ancient times. The coil incense made by the mold has uniform thickness and average burning speed. You can also know the time by looking at the scale on the coil incense. It can also act as an alarm clock. When the coil incense burns to a certain point, the heavy objects hanging on the coil incense fall and hit hard objects, making a sound.