Do changes to the past affect the future and vice-versa?

[Philosophy Explorer]

I would say it makes as much sense to move across space as it does to go back in time. So the question becomes whether you believe in thermodynamics. Because if you do, then your chances of moving across that wall is nonzero while you can't go back in time, according to thermodynamics. But since thermodynamics is an assumption, we don't know for sure that entropy will go to zero or maybe even go up because it's an assumption. Until it's absolutely proven without a shred of doubt, time travel will always remain a possibility.

PhilX

[Leog]

(Nested quote removed.)


What do you mean by "traveling to the past"? Such a thing is undefined.

There are many terms that are undefined in science. I'm guessing that you are looking to know if it means you are physically going into the past and the answer is yes.

PhilX

Sorry, I cannot understand what "you are physically going into the past" means. You want to revert the time flow? Say, you want to "travel" to the year 2000, so you will become younger and younger and eventually reach the year 2000 when you are 14 years younger? But or world is irreversible (at least because of the 2nd law of thermodynamics).

Or you want to destroy our existing planet (besides yourself) and re-create it exactly the same state as it was at some moment in 2000 plus put yourself on that re-created planet?

Well, suppose the second scenario were possible (though it is for sure not). So you of the year 2014 are now on Earth created in 2014, and this Earth looks exactly as it were in 2000. And you start making your changes on that earth. What will happen in the next 14 years? Well, you will live your life, do something and become another 14 years older. That's it. Of course you can meet the 14 years younger "yourself" there - so what?

Of course, your addition to the 2000-looking Earth will change it and this Earth in 2014 (which in fact will be 2028) will be different than it were without your arriving.

But if you even could re-create the Earth of 2000 now, in 14 years it will be different from the original 2014 Earth in any case, because our world is not absolutely deterministic and starting from exactly the same states may develop differently.

(Though the "state of the world" cannot be defined...)

But the time travel to the past can be done in virtual reality, for example, in comuter game...

[Felix]

FYI, I actually live about 100 years in the future and am just visiting this time zone for a while - I'm doing historical research on primitive computer technology.