In modern science fiction and gaming, the FTL downgrade typically manifests in one of three ways.
To keep a wormhole throat open wide enough for a human to pass, you need "exotic matter" with negative mass/energy. This isn't hypothetical dark matter; this is matter that repels gravity. While the Casimir effect proves tiny amounts of negative energy exist in quantum foam, the amount required for a wormhole is astronomical. ftl downgrade
To downgrade FTL: Faster Than Light (usually for modding like FTL: Multiverse Hyperspace ), you typically need to revert the game to version Subset Games Downgrade Methods In modern science fiction and gaming, the FTL
In 1994, theoretical physicist Miguel Alcubierre provided a mathematical solution within General Relativity that allowed a warp drive. It didn't move the ship; it contracted space in front of it and expanded it behind, riding a "bubble" of flat spacetime. While the Casimir effect proves tiny amounts of