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Born in today Nanyang County Henan, he was a good writer at age 12. At age 16, he left home to pursue his study in the capital cities. He spent at least 10 years of his youth in literature studies and writing. He published several well recognized literary writings. He switched to astronomy after age 30. He became a government official at age 38. He took on several positions since then (including 郎中, 太史令, 尚書). When he was a government minister, he cleaned up some corruption in the local government.

In the year 123 he corrected the calendar to bring it into line with the seasons.

In 132, Zhang invented the first seismograph for measuring earthquakes. He theorized that the universe was like an egg with the stars on the shell and the earth as the yolk. Zhang Heng was the first person in China to construct a rotating celestial globeThroughout Chinese history, astronomers have created celestial globes to assist the observation of the stars. The earliest celestial globe was dated back to 52 BC in the West Han dynasty by the astronomers Geng Shou-chang and Luo-xia Hong . The first wate. He also invented the odometerAn odometer is a device used for indicating distance traveled by an automobile or other vehicle. It may be electronic or mechanical. Mechanical odometers usually appear as a row of wheels with the edge of the wheels towards the person viewing it. There ar.

In one of his publications líng xiàn (《靈憲》 a summary of astronomical theories at the time), he approximated piOr pi with a lower-case p . minuscule, or lower-case, pi The mathematical constant (written as pi when the Greek letter is not available) is ubiquitous in mathematics and physics. In Euclidean plane geometry, π may be defined as either the ratio of a c as 730/232 (or approx 3.1466). In one of his formulae for spherical volume calculation, he also used pi as square root of 10 (or approx 3.162).