[clueless (OP)]

It appears, there IS a mathematical reason why a time travel machine could not be able to disrupt spacetime continuum enough to go backwards in time.

The proof? Here we go. Let us suppose that you just invented a time machine. Yay! Naturally, you want to try this hot rod out, that is to say, you are about to press the button for traveling into the past at a certain speed. However, since you neglected to include temporal shields to encompass and protect the time machine, and, of course, you in it, it appears the following will happen: a temporal loop. Time loop is a plot device in which periods of time are repeated and re-experienced by the characters; but in this instance, there is no hope of breaking out of the cycle of repetition, so it is more of a casual loop, I think. To cut a long story short, you will be pressing the button (for time travel) forever (!) in this time loop forwhy you haven’t temporal shields around your time machine. In other words, the moment you press the button for time travel you WILL travel back in time, but for the duration less than a nanosecond (!), more precisely, to the moment when you are about to press the button. So, this time loop, with duration of a blink of an eye, is likely to occur at the very first try at time travel — without the temporal shields. Am I wrong to think that? Did You think of it already?

[Kryptid]

I'm afraid that I don't understand your reasoning.

What about scenarios where a machine is not involved? For instance, how would this apply to a wormhole whose mouths are placed at different gravitational potentials and thus experience time dilation at different rates?

[clueless (OP)]

Well, my reasoning is that, when you press the button for time travel, and into the past, you do just that: you travel back into the past right before pressing the button, unpressing the button, if you will. And since at that particular time you still have the same desire: to press the button, you will not be able not to push/unpush the button again and again and: forever; unless: you acquire temporal shields that will shield you from backward time travel (into the past), while everybody else will then walk backwards. Hmm. Does it make a bit more sense now? I am no expert in temporal mechanics, not in the slightest; but it seems to me that my logic is not flawed.

[Kryptid]

I think I understand what you are saying now. What you are saying is that pushing the button causes time itself to reverse for everyone, right? The person who pushed the button included? I think a wormhole-based time machine would get around that problem, since time itself is not reversing. All you are doing is allowing two different mouths of the wormhole to age at different rates (which, in turn, would prevent you from traveling back in time any further than that which the wormhole was first created).

[clueless (OP)]

Yep. That's what I mean.

Well, you can't go around a hypothetical wormhole. I see your fine point though. There is always a way.

[Kryptid]

At this point, wormholes are only mathematical entities that might allow for time travel. They may not exist at all.