In 132 CE, Zhang Heng presented his latest invention: a large vase he claimed could tell them whenever an earthquake occurred for hundreds of miles. Today, we no longer rely on pots as warning systems, but earthquakes still offer challenges to those trying to track them. Why are earthquakes so hard to anticipate, and how could we get better at predicting them? Jean-Baptiste P. Koehl investigates in this new TED-Ed video animation.

The video includes a quiz of 8 questions in the “Think” section and more about the topic in the “Dig Deeper” section. It is also possible to interact with other curious souls in the “Discuss” section.

The video is available below. For the full experience, visit the animation at