There are many seemingly impossible ideas which may allow for time travel in the far future. Many of these theories rely on technology which has not been created yet, such as spaceships that can go close to the speed of light, or on concepts which have not been proven, such as a sustainable wormhole. However, many of these theories are promising, and plausible. We will be focusing on wormholes, the infinite cylinder, string theory, and black holes. We will also explain some problems and paradoxes which may be created if these devices were ever to become a reality.