漫步天上的街市 2011-12-25 孙小淳 http://bbs.astron.ac.cn/thread-82535-1-1.html Astronomy tells us time, in city we can’t see the stars, we are farther from astronomy, but underlying official time is still given by astronomy. Astronomy tell us time, seasons From historical records of astronomical events, we can know when they happened by their recorded positions at the time. Current famous constellations are Western, people (esp kids) know them, esp zodiac. China also has its own historical constellations. Western constellations are from mythology. Chinese constellations are every objects projected on the sky, very methodical. 《天官书》collected star names from famous astronomers Different star names appear in different classic books 夏小正 诗经 二十八宿 ershibaxiu Dunhuang had star maps (on paper) with constellations Names of Chinese asterisms come from many different categories, 你能想象的东西你在天上能找得到 Even bathroom asterisms: pot, lid, pee 屎 (must be a yellow star!) Lots of old texts on philosophy of astronomy, from 天官书，灵宪 Ancient Chinese built up their astronomy based on their needs, their culture. So we need to understand their culture. Goals: understand laws of nature, built a connection between nature and man. Comet or planet “entered” a certain constellation, the same object on the earth would have something happen to it. Talk’s title comes from a poem by Guo Moruo, look it up 天上的街市 He saw stars as lanterns held by people on a road. Different people/cultures, see different things in the skies [Constellations are old school. Nowadays, science fiction connects us to science/nature.] [Teaching idea: Find new constellations in the sky, connect them to things in our modern world.] 五天廷 Google this 中宫 Google this! 石氏星官 汉代 used a different star for the north star (now Polaris) If you tell the speaker which star is the north star, he can tell you the era. Poems were written explaining the significance of the stars and asterisms of the time. 史记天官书 Confucius used the stars to explain his ruling philosophy, be like Polaris, sit still everything will revolve around you. 东宫苍龙，房心 Moon goes through different doors, has different meanings. Meanings may have different interpretations, but the events themselves are carefully reported, indisputable, and have scientific significance. 西宫咸池，参为白虎 北宫玄武，虚危 Han dynasty astronomer 张衡 《思玄.贝武.》 Poem with lots of star/constellation names in it. 帝王巡狩 King needs to visit parts of his kingdoms according to appearance of the constellations in the night sky. 太微 阁道，天狼，垒壁阵 曹操《观沧海》 not sure what this means, about the king’s travels? Like we saw that names of stars/constellations reflect objects on the earth and heavenly events are used to predict events on the Earth, the same kind of connections were made between constellations/stars and places on the Earth. The emperor monopolized this kind of information in order to control the people. Example of 秦赵长平 Qin conquering Zhao, other kingdoms came to Zhao’s help, there was a heavenly event in one of the 28 xiu, it was interpreted by the two groups of advisors differently and oppositely, Qin would destroy Zhao, or heavenly forces would help Zhao. Was the moon covering maoxing to defend it, or to wipe it out? Example of 帝王以星占督兵, Venus close to the sun but above the horizon in the morning, five major planets all in the sky at once. Emperor said must send troops, general refused. Example of 龙湾之战, 1360 陈友谅 planets were aligned, one chasing another, so decided to attack. Science and ancient astronomy. 占星 star brightness Bright to dim: 大者，明者，no special name，小星, ?? (missed) Variable stars were observed and described, this has scientific significance for us Same with stars of different color, “black” stars were stars that were deep red. Stars with colors before have changed to present day, give lifetimes for certain kinds of stars. Star names have cultural significance, but also scientific significance. Classification systems. Astronomy is both culture and science. That’s how we should understand ancient Chinese constellations. The sky is beautiful. ------------------------- Q&A session Professor Ling Qing Christmas is being accepted in China because it’s a time for wishing prosperity, peace to everybody. The talk was supposed to be yesterday, so taking advantage of the schedule change to with you Merry Christmas. Also, 2012 is a myth haha. We will address that in talks next year. Q. China used astronomy to assert political control, drew connections between stars and history. Did this happen in the west? A. In the west, it’s been traditionally connections between stars and personal lives not government. Q. Historical precedent for 2012 connection to astronomy? A. During times of crisis, many instances of end-of-the-world predictions. We need to understand these from the perspective of science. Q. Ancient China couldn’t see southern hemisphere, so maps were incomplete? A. Yes. 老人星 at 5 degrees of altitude, if it could be seen it was a sign of good fortune. Actually from Hainan it was easy to see, but most of our records come from north, Luoyang, etc. Xu Guangqi’s time, western missionaries brought southern hemisphere stars to China, given 23 Chinese names: peacock, snake, etc. Q. What good reading materials on this topic? A. [Forgot to answer in answering the next question.] Q. Constellations, will there be any new ones? A. Increased in number over time, now studied and measured. Hard to make people accept new constellations. Have been attempts, especially among religious groups. Problem is getting people to accept them. Must preserve what we have, esp Chinese traditional asterisms. Q. Do astronomical events affect earthly events? A. Only through people (superstitions, cultural beliefs), as far as science knows. Of course, when the sun shines we feel warm, the moon produces ocean tides, the orbit of the earth produces the seasons, but you can’t connect stuff without evidence of direct influence. Things that are far away from us are less likely to affect things on the Earth. Thank you prof Sun. -------------------------- Science trivia quiz and prize drawing Prof Zhang Yao