Redirected from 643 BC
Decades: 690s BC 680s BC 670s BC 660s BC 650s BC - 640s BC - 630s BC 620s BC 610s BC 600s BC 590s BC
Significant People
... but start precessing around. (The precessing motion is perpendicular to the torque trying to make the gyro fall over.) The axis of the gyroscope in the Dynabee is fixed ...