Quotation
In practice, people do co-operate in many ways, despite the lack of individual benefit. ... But co-operation is fragile, as gun control and gang revenge questions indicate.
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The same applies to another famous problem Poincaré attacked, also featuring the number Three. This is the three-body uproblem.
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… it is difficult to recover the excitement of the seventeenth century, when the solar system became the test-bed for mathematical prediction. The periodic return of Halley’s comet, whose successful prediction was one great early achievement, is a reminder of that original drama of the skies.
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Electric force becomes stronger and stronger as two charges approach. Colour force is the other way round. It acts like a spring, becoming stronger as two colour charges separate, and diminishing to nothing as they approach.