Like some weird type of optical fiber, a long, thin wormhole might let you send messages through time by making use of pulses of light.
Anticipated by Einstein’s general theory of relativity, wormholes are tunnels linking a couple of points in space-time. If something could traverse one, it would open up interesting possibilities, such as time travel and quick communications.
But there’s an issue: Einstein’s wormholes are notoriously unsteady, and they don’t stay open for long enough for anything to pass through. In 1988, Kip Thorne at the California Institute of Technology and his team theorize that wormholes could be kept open using a sort of negative energy called Casimir energy.
Quantum mechanics informs us that the vacuum of space-time is abounding with random quantum fluctuations, which form waves of energy. Now anticipate two metal plates situating parallel in this vacuum. Some energy waves are too massive to fit between the plates, so the amount of energy between them is less than that bordering them.
Slow collapse
A wormhole is a shortcut through space-time, so transferring a light pulse through one could let faster-than-light communication. And as the two openings of a wormhole can exist at different points in time, in theory a message could be directed through time.
The butcher cautions that a lot more work is required to firm that other parts of the wormhole besides the core remain open long enough for light to form it all the way through. He also requires working out whether a pulse large enough to transmit meaningful data could sneak through the slowly collapsing throat. And, of course, we are a very long way off translating the theoretical equations into a physical object.
Reference: arxiv.org/abs/1405.1283v1