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I am fascinated by the idea of a tug of war between Dover, UK, and Calais, France, with thousands of people on each side, 42 kilometres apart. Could a rope be made long, light and strong enough for this? (continued)

Mike Tongue
Newark, Nottinghamshire, UK

To stage this tug of war you could actually dispense with a rope that spans the sea between the two countries and instead install a servomechanism – a device that automatically corrects the actions of a mechanism – in Dover and Calais. Each would consist of a winch and load cell. The pull on each load cell would be compared using control software, resulting in rope at each end being pulled in or let out as appropriate.

Previous responses didn’t mention Earth’s curvature. If a rope were pulled to a straight line between Calais and Dover, at its midpoint the rope would be 40 metres under the sea.

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