Cecil’s column: If all Chinese jumped at once, would cataclysm result? (06-Apr-1984)
From radio station Deutsche Welle:
A German science TV show wondered what would happen if many people jumped at once, and convinced 50,000 people at a rock concert to attempt this feat. The Potsdam Geological Research Center recorded it on seismometers. Results: the ground moved one twentieth of a millimeter. The amount of energy required for an earthquake would be billions of times greater.