If Time Travel is Possible - Couldnt We Lure a Traveller in?, page 1

Physical time travel is a very difficult situation to approach. The paradoxes multiply so fast, largely due to the fact that we don't really understand how time works on the physical level.

Lets postulate a scenario. Jack is a military officer chosen for a mission. His job, if he chooses to accept, is to return to the present from a specific point in time in order to facilitate us with information about the future choices of world leaders and political environments. There are only two requirements, in theory, needed to fulfill this mission:

1. The machine must be turned on and remain on and working
2. Jack must be willing to carry out his duty and return from the appointed future to the appointed past.

The machine is turned on, and an hour later the time of return has been reached. What happens?

If Jack emerges from the machine we will have instantly created a universe wherein there are two Jacks, the present day Jack who has not yet reached the future point whereupon he is to return, and the future Jack who has, right?

We have a serious problem now, because we are no longer certain if the future Jack is from a future that is even relevant to our present universe. Present Jack was to wait 10 years to return, but clearly he is still here and only an hour has passed. How is it then that future Jack can even exist?

Two main possibilities come to mind. The first is that by merely building the machine, turning it on, and giving someone this mission we instantly create a future wherein this mission is fulfilled, and thus despite the fact that only an hour has passed, a man from ten years in the future returns to us with information about our future. However in this scenario we are dealing now with a present which is different from the present of the Jack who has returned to us (his past). In other words, in his past he is the only Jack, whereas in our Jacks past there are two. This changes something, if not potentially many things, about the world our future Jack is from, his information cannot be 100% reliable.

The second is that we will never see this event unfold ourselves. Since we are the original time line wherein the machine is created, we have actually created an alternate past, one which we will never experience. We will have to wait for ten years, then send our one and only Jack into the past. However in this case we are forever doomed to this fate until the end of time, if there is one, since we will forever be the first to create the machine, it will be our duty to perpetually send people back into the past to fulfill these missions, with no knowledge of how it is effecting the future of the worlds upon which these men are emerging. For that reason alone the mission may eventually be abandoned since it does us in the present no good, and because of its unpredictable nature we may be precipitating and creating new problems rather than fixing existing ones.

The question here is can we of this world and this reality ever experience the presence of a physical time traveler due to these problems?

In one scenario we end up with two Jacks, in another we end up with none.

In yet another far more complex scenario we must shut the machine down entirely, or perhaps the machine breaks down in quite a mess. See, if we are able to create the future by merely building the machine, there is the possibility that we create multiple futures wherein Jack returns to the present to inform us of our future. How many Jacks do we have then? Do the numbers approach infinity? Do they all try to come through the machine at once? Would the machine even respond? In this case its easy to imagine many possibilities wherein the machine is unable to handle the load, or where the present suddenly explodes with Jacks (in quite a bloody and horrifying mess) at the moment of return and the machine is destroyed in the process.

Thus there is no guarantee that creating a time machine will actually result in meeting people from the future.