Zhang Heng

Zhang Heng (Chinese张衡/张衡, Pinyin Zhang Heng, Heng Chang W.-G.; * 78 in Nanyang, † 139 in Luoyang ) was a Chinese mathematician, astronomer, geographer, writer and inventor of the Han period.

At the age of 16 years Zhang Heng left his family to study in various Chinese cities. It first deals with the literature and had written several respectable literary work, he turned to about 30 years of astronomy. He soon earned a reputation as a scientist and entered the service of the Government as such at the age of 38 years. He quickly made a career and was finally under Emperor Liu Hu (An - ti) minister and chief astronomer of the Han Dynasty.

In this position, he led in the year 123, a reform of the calendar system a, with the aim to bring the months again with the seasons in line.

Zhang's cosmological world view based on the idea that heaven and earth were spherical, with the earth in the center.

Zhang Heng was the inventor of the first seismograph well - or more precisely, the first Seismoskops - in the world. A invertes pendulum was thereby set by the quake waves in motion, which in turn triggered a ball through one of the dragon heads. She fell into the corresponding toads mouth and produced a signal. The respective dragon's head indicated the direction of the Bebenepizentrums.

The grave Zhang Heng is on the list of monuments of the People's Republic of China since 1988.