Why altering time should be impossible. (in theroy)

[Depom]

Lets now take a senario where i lost a loved one.
So i go back in time and prevent this person for dieing.

This will create a paradox where I never lost this person and have no need to go back in time to save them, thus i dont, and they will stay dead.
This works the same for any other given senario you find your self going back in to alter time, removing the reason for you to go back and change it in the first place.

This is flawed reasoning and I'll explain why by analogy. (Side note: I don't mean that an analogy is proof of anything, it was just the simplest way to explain how I think on the subject of the grandfather paradox and similar)

Let say you put a ladder up against a roof and climb up. Once up, you push the ladder over. Even thought there's no longer any way to get up on the roof, you are still there.

Now think of the ladder as the chain of events that led to your inventing time travel/going back and the roof as the act of saving your loved one.
Even though there's no longer any need to time travel and save them, you still did.

[LuxyEU]

Again, lots of good comments and lots of eh, not so good ones.

It has given me some other things to take in to consideration about altering time (in theory ofc).

another diclaimer: nothing that is said here should be taken serious as its only a theory, we're not thinking for a second here that traveling back in time is possible.

[AcrobaticMegalodon]

I mentioned this in an earlier post in this thread, and I haven't really looked at the posts regarding if Time Travel is POSSIBLE. I'm more interested if the paradoxes mentioned by the OP will be a problem.

We humans consist of atoms, and throughout our life they get replaced. We don't have the same atoms as 10 years ago, or the day we were born. Also, the human body didn't CREATE the atoms, the atoms created it. So in order for the paradoxes to happen, you don't have to, for example, stop your grand parents from meeting.

You simply have to go back in time for that, because according to physicists, if you start over the big back, another universe would be created and we wouldn't exist. This is a probabilistic universe, not a deterministic.

Not only that, if you go back in time, what are you exactly doing? Are you undoing what has happend, are you going into a past universe? If it's the latter, the paradoxes wouldn't happen. But if you're undoing everything, you're not connected to your future self, for reasons listed above.

So how is your currect self in any way connected to your post/future selves? They consist of different atoms, there's nothing magical about it. If you go back in time, will the universe care about how that collection of atoms got there? I think the universe will just take it as matter poping out of nowhere, and I don't think that will have any impact.

If anyone still believes paradoxes will occur, I'd love a response.