男友太凶猛1v1高h,大地资源在线资源免费观看 ,人妻少妇精品视频二区,极度sm残忍bdsm变态

Longest day is a turning point

By Wang Ru | China Daily | Updated: 2022-06-21 06:59
Share
Share - WeChat
The observatory built under the direction of astronomer Guo Shoujing (1231-1316) in Dengfeng city, Henan province, stands testimony to the understanding of the sun by ancient Chinese. [Photo/Xinhua]

The platform is a guibiao, an ancient Chinese sundial with a gui, a horizontal scale on the ground extending to the north, and a biao, a perpendicular bar standing upright. As the sun moves, the shadow of the biao is cast on the gui, and the length of the shadow at different times helps to trace variations of the sun's movement.

"It is said that the ancient Chinese found a day when the shortest shadow cast was about 50 centimeters, and that was the start of summer's hottest period. That is how the Summer Solstice was discovered," says Lyu, who is also director of the office of Dengfeng chronicles.

Ji's original platform was made from wood and earth, and being hard to preserve, had to be replaced many times over the years. Standing in its place today is a permanent guibiao, rebuilt using stone during the Tang Dynasty (618-907), that continues to tell stories about ancient Chinese endeavors in astronomy.

About 20 meters from Ji's platform is another observatory, built under the direction of Chinese astronomer Guo Shoujing (1231-1316) during the Yuan Dynasty (1271-1368), which has a similar structure to a guibiao, but is much larger in scale.

Guo built 27 observatories throughout the Yuan territories, and the one in Dengfeng is the only one that still exists. Based on his observations over the course of two years, he developed a new calendar called Shoushi Li (season-granting calendar), calculating a year to be 365.2425 days, just seconds off the current measurement of a year. The calendar was used for more than 360 years.

|<< Previous 1 2 3 4 5 6 Next   >>|

Related Stories

Top
BACK TO THE TOP
English
Copyright 1995 - . All rights reserved. The content (including but not limited to text, photo, multimedia information, etc) published in this site belongs to China Daily Information Co (CDIC). Without written authorization from CDIC, such content shall not be republished or used in any form. Note: Browsers with 1024*768 or higher resolution are suggested for this site.
License for publishing multimedia online 0108263

Registration Number: 130349
FOLLOW US
主站蜘蛛池模板: 于都县| 九江县| 大港区| 秦皇岛市| 太仓市| 永泰县| 四子王旗| 左云县| 天水市| 罗城| 竹溪县| 乌什县| 巴里| 平阳县| 依兰县| 海伦市| 常山县| 瑞金市| 乳源| 保亭| 两当县| 东丽区| 剑河县| 沁水县| 盘锦市| 太原市| 喜德县| 大连市| 集贤县| 祁连县| 洪雅县| 灵山县| 酒泉市| 吉木乃县| 班戈县| 民和| 江川县| 旬阳县| 蒙山县| 商城县| 黄浦区|