Three Gears are Possible Well three gears are actually possible. Facebook Prev Article Next Article Discover Checkout these cool gadgets... Related Posts 13 Medical Procedures Changing The Health World NASA – A Week in the Life of Rain Making Artificial Earthquakes with a Four-Tonne Steel Ball How 3D Printers are made Where Did Earth’s Water Come From? DNA Sequences Can Trace Your Ancestors to Within 30 Miles