A practical way to time travel isn’t to build a machine that can travel in time but to build a machine that can manipulate physical objects or events in the real world to a before or after state at an atom level. This method isn’t really traveling in a timeline, where a time traveler has the freedom to travel forward in time or backwards in time. It’s, in actuality, preserving the continuity of time, and time is still a point moving slowly in one direction along a straight line. The AI is operating in linear time and is simply manipulating objects to the way they were in the past or will be in the future at an atomic level. This is important because it solves the grandfather paradox, and solving of this problem is essential and leads to practical time travel into the past. Since this AI time machine can manipulate any object on Earth, it can also select which objects to manipulate and which objects to leave untouched. If a time traveler wanted to travel back to 1984, the object that is untouched is the time traveler, and all other objects on Earth are subject to targeted time travel.