The first gear takes about 3.5 seconds to turn. The second gear takes about 35 seconds, or 3.5x10^1. The fifth wheel will take around ten hours to turn once. In a month, the seventh wheel will have almost one rotation. The eighth will take a little over a year. If you watch this machine from the time you are born until the time you die, you will probably live to see the tenth gear make most of one rotation. The eleventh will take over a millennium to turn, the twelfth considerably longer than all of recorded history, and the fourteenth wheel would take about as long as humans have existed. In the time since the dinosaurs went extinct, the sixteenth wheel would turn a little more than half way. Earth's existence has been long enough to get the eighteenth wheel half way around, and in the entire history of the known universe the twentieth gear would move by just over one tooth.
