A gyroscope is a heavy metal wheel made with ball bearings that reduce friction. Once the wheel is set spinning at high speed in an upright position, the force of gravity will try to topple it. However, the effects of gravity are countered by another force called precession. This force means that a spinning body tends to move at right angles to any force that tries to change its direction of rotation. The effect is to keep the gyroscope in the same position until it has slowed down so much that gravity overcomes precession.
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