Closed Time-like Curves (CTCs)

Closed Time-like Curves (CTCs) are theoretical paths in spacetime that loop back on themselves, meaning an object traveling along such a path could theoretically return to its own past. Imagine a spaceship following a route that eventually brings it back to the same point in time it started from, allowing for the possibility of time travel. While solutions in general relativity suggest such curves could exist under certain extreme conditions, their physical plausibility remains debated, and they pose complex issues like potential violations of causality (the cause-and-effect relationship).