Over 1,800 years ago, long before modern technology, the ancient Chinese astronomer and inventor Zhang Heng created the world’s first seismograph in 132 AD. This ingenious bronze device could detect distant earthquakes by releasing small balls from dragons’ mouths into toads’ mouths—each indicating a different compass direction. Its historic detection of an earthquake 400 miles away astonished the imperial court and transformed the way societies understood and responded to seismic events. […]
The World’s First Seismograph: How Ancient China Detected Earthquakes 1,800 Years Ago
