Comment on Make it so
brucethemoose@lemmy.world 1 week ago
It still violates causality
Orion’s Arm has an elaborate write-up for their wormhole system. to get around this:
www.orionsarm.com/eg-article/48545a0f6352a
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 an exponential flux of virtual particles, which destabilises the wormhole and causes a collapse.
This represents an effective event horizon between the (hypothetical) part of the universe which allows time travel and the part of the universe which does not; this horizon is known as a Cauchy Horizon.
In other words, one can’t place wormholes in a configuration where they’d violate causality; the act of doing so creates a black hole.
And this includes more complex configurations that could indirectly generate a CTC; in other words, for a large networks, one basically needs high artificial intelligence to arrange a wormhole network to avoid a “roman configuration” where they’d explode.