Permalink https://philpapers.org/rec/TURTMA-5 TL;DR: The laws of physics seem to prevent us from accidentally erasing our own history through time travel. However, this same protection might mean that any civilization advanced enough to build time machines gets destroyed before they can do so – nature's way of maintaining consistency. Does the potential creation of a time machine present an existential risk to our current timeline? Time travel is theoretically possible under general relativity, and there is steady progress (similar to Moore's Law) in developing ideas about how to create time machines with decreasing effort. While time travel may seem like a remote possibility due to its dependence on space travel to black holes, there is a concept of a quantum time machine (suggested by Deutsch in 1991 and further developed by Lloyd in 2011) that would require much less energy to send a few bits back in time and could still cause paradoxes. An artificial superintelligence (ASI) might soon create such a device, especially in scenarios where multiple ASIs compete for control with each other.