The inventor was frustrated. He had spent years, decades, researching the nature of time, and his work had finally come to fruition: he had invented a — theoretically — functioning time machine. With this he knew he could silence all the naysayers who had repudiated the underlying goal of his research. They had told him, time without number, that time travel was impossible. Otherwise, one could create a paradox by, say, going back in time and killing one’s grandfather before he had any children. In which case, the time traveler would never even exist, and so wouldn’t travel back in time to kill his grandfather, thus ensuring the grandfather’s procreation, and the time traveler’s eventual existence, enabling the latter to go back in time and kill…
Fah. He had long ago dismissed such nonsense, but as he achieved greater and greater success in his research (always in the comfort of his lab at home rather than at work) the problem grew in his mind. It did not occupy his conscious mind, but his unconscious thoughts were frequently considering it, weighing particular solutions, allowing the better ones to step up to the next floor in his mental architecture. This was actually how he did most of his thinking, with the result being that by the time an idea actually manifested itself in his conscious mind, he was essentially already decided on a course of action.
Obviously, he had concluded, a man could not travel back in time and prevent the circumstances by which he traveled back in time in the first place. Just as obviously (thus the paradox) there would be nothing to stop a man from doing precisely that once he had already traveled back in time. Therefore, both conditions must be true. A man could travel back in time and kill his grandfather. But then he would continue to exist: and upon his return to the present, he would discover that his grandfather had not been killed. Time travel, in other words, would only allow for observation, not interaction. No one would have to worry about accidentally stepping on a bug and somehow causing a volcanic eruption or whatever. This led to important side issues: were one’s actions actually happening somewhere (or somewhen)? What would happen if one then got stuck in the past where the apparent event had taken place? Etc. But his subconscious was already working on potential solutions to these questions.
As to the main question, he had already decided what to do. Before he would bring his time machine to the attention of his colleagues (and the world for that matter) he would first have to divest them of this notion of paradoxes. To this end, he would travel back in time, perform an action that could not have happened, and then return to the present. He would do this with other people so they could verify that he had, in fact, done the impossible act in the past without endangering the present in any way.
First, though, he would have to do it alone in order to have empirical verification (of a sort) in hand before approaching his colleagues. He did not want to kill his grandfather, and was certain his explanation would not be believable if he got stuck 80 years in the past. So instead, he would travel five years into the past and kill himself — his self from five years ago, that is. If, per impossibile, he got stuck there, he was pretty sure his presence would prevent any murder accusation from getting off the ground, the alleged victim being alive and well.
He took his time machine (which was about the size of a shoebox) and a pistol into the hallway outside his lab, turned the number dial on the time machine to “5”, the units dial all the way up to “year”, the directional switch to “past”, and activated it. Not much changed, but he hadn’t expected it to; he had always relished continuity (which made it a little unusual that he, of all people, would invent a time machine), and so his furnishings had remained almost entirely unchanged over the thirty-plus years that he’d been living in this house. He expected to find himself at work in his lab, and so walked over to it. The door was open a crack, and he was able to look in and see that, yes, he was indeed sitting at his desk, looking at something. He raised the pistol, pushed the door open, and before his old self could react to the sound of the creaky hinges, he shot himself in the head. His old self.
He paused for a moment to see if he noticed any differences: did he have any new memories? Did he still exist? Would one notice if one stopped existing? At this last thought, he chuckled, stepped into the room, and then pushed the return button on the time machine. Apart from the disappearance of his body — his old body — and the door closing most of the way behind him, nothing changed. After pausing again to see if he noticed any differences (he didn’t), he went over to his desk to record the results of his experiment. He looked at the time machine and called up the exact coordinates it had recorded, and began writing them down.
But something was wrong. The coordinates were not what they should have been, not even close. As he finished writing them down, he looked back at the time machine to see what the problem was. The first thing he noticed was that, although he had pushed the directional switch down for “past”, the switch was sticky and it hadn’t clicked over. The second thing he noticed was that, while he had turned the category dial all the way up to “year”, he accidentally pushed it too far: and since the dial had no stopper, it reset to the smallest unit.
He hadn’t traveled five years into the past. He had traveled five MINUTES into the FUTURE.
And behind him, the door hinges creaked.
Credit To – Jim S.