Visser Effect

Principle that dictates that no system of wormholes can be configured in such a way as to permit time travel

Image from Steve Bowers

When a wormhole is transported to a distant system by linelayer at relativistic speeds, the two ends of the wormhole become displaced in time due to time dilation. In theory this displacement could allow time travel into the past, especialy if the wormhole mouths are subsequently brought close together again or connected via additional wormholes.

In practice time travel into the past is prevented by the so-called Visser effect. The ends of any single wormhole cannot be brought more closely together than the time difference between them; i.e. if one mouth is a year younger than the other, the ends can't come closer than a light-year without causing a Closed Timelike Curve. The formation of such a CTC immediately generates a Cauchy horizon which destabilises the wormhole and causes a collapse.

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Development Notes
Text by Xaonon
Initially published on 12 December 2001.

See Also

Why is there no Time Travel in Orion's Arm?