Zhang Heng (astronomer and inventor)

Zhang Heng (78–139 AD) was a Chinese astronomer, mathematician, and inventor known for his innovative contributions. He improved the lunar calendar, accurately predicted celestial events, and created a seismograph capable of detecting earthquakes hundreds of miles away. His inventions included a water-powered armillary sphere to model celestial movements and an early compass device. Zhang Heng’s work advanced understanding of astronomy and physics, bridging science and technology in ancient China. His achievements influenced both his contemporaries and future generations, showcasing a remarkable blend of scientific insight and practical invention.