In certain spacetime geometries governed by general relativity, such as cosmic strings, traversable wormholes, and Alcubierre drives, there exists a theoretical possibility of traveling to the past by surpassing the speed of light. The scientific foundations of general relativity lend support to the notion of backward time travel in specific extraordinary circumstances. However, when quantum effects are taken into account, arguments from semiclassical gravity indicate that these potential avenues might be closed. Notably, these semiclassical arguments prompted Stephen Hawking to propose the chronology protection conjecture, suggesting that the fundamental laws of nature prevent time travel. Nonetheless, physicists are unable to reach a definitive conclusion on this matter without a unified theory of quantum gravity that harmonizes quantum mechanics and general relativity into a comprehensive framework.