Can retrospective past actions change a future that has already happened?

Some variations on the classic “double-slit experiment” using entangled particles may shed some light pardon on this. They look very much like cases of an action changing something which has already occurred, or of future actions influencing present outcomes.

I’d have to look again at the particulars, and the explanation would be long and tedious. How interested are you?

I like these topics as it usually involves theory of the what if of life. If you first consider the billions of years that have passed to first form the earth and then allow for life to develop and fast forward to know….a lot has happened to get us to this point. One school of thought says it is all random interactions of atoms flying through space, colliding, gravitational influences to make and form all that there is today. This same school of thought says this randomness is also predetermined by these random interactions as there is a cause and effect. So any one event then set off and will be part of the future and new reactions will happen. That is the interesting part….“will happen”!! So ineffect this randomness has predetermined what will happen…even though it is random, it will happen as it was supposed to happen all because of these random interactions before. You could almost say I was going to write these words because of atomic events millions of years ago. Even the day I will die is already set in place….the how and why I die is already scripted in a sense and I have no say so…even if I go and kill myself….that was already supposed to happen! Weird stuff.

Now consider just how many atoms bumped into each other since the beginning of time till now to form every planet and star and then all the evolutionary processes and if/then events of our past that shaped the world we live in today.

My brains will soon overheat and liquefy if I think too hard on this. So it would seem quite obvious that any travel back in our time will have a hugely consequential effect on our present and future. Just going back whenever and kicking a grain of sand could set off a whole series of events that otherwise would not have ever happened.

This leads me to believe time travel at least in your own time line is not possible or I believe we would not be in the shape this world is in. Perhaps time travel is possible as some suggest in a multi-verse scenario but I don’t think we have fully fleshed that possibility out yet! I hear there is some heady findings as of late a Cern that have the scientists really scratching their heads that will open new doors toward even more ways of thinking about time and time travel.

@thorninmud Feel free to make sense in any way you want. I’m more interested in what you choose to say than in hearing research about time and whatnot. I am particularly interested in the way we interpret this given that things like @Cruiser‘s brain liquification are happening. What does that mean? Why do we mess with these ideas? Why do we let them twist our minds in knots? We must get something out of them besides craziness. What does it do for us?

@wundayatta For me it allows my mind to take a free ride away from the rudimentary aspects of my life. Sort of a mental Sunday drive just enjoying where my thoughts take me. My whole life I have questioned EVERYTHING and often there are easy answers to find. But the more answers I get the more I know about which inevitable raises more questions. Nobody knows exactly how we got here…we seem to know when it all started but how long will all this last?? And what about before that?? And yes what about time travel? Why not time travel and dammit how the hell do we do it!! I want to know NOW!! XD

So, we’re assuming the past has already happened. I am wondering what you mean by “retrospective past actions” more specifically.

I’ll say that I think about it like this – from a time travel perspective if we consider time travel to the past from out current time, I think that it’s necessary to consider (1) there are several (close to infinite) timelines, (2) the future has happened for many, they started at an earlier time, or move at a speed different from this one so time is compressed in a manner that makes it a later date there from our perspective.

Things seem less brain-liquifying to me when I abandon my perspective in which I’m moving through time. That perspective is useful as a conventionally agreed-upon model, but it leads to the kinds of mental tangles we’re playing with now.

Things get radically simpler when you stop trying to track entities through time, as if they could be reified and isolated. Give up the idea of entities and time all becomes one big now.

I think both ways of looking at it are valid, and each brings something of value. Either view, all by itself, is inadequate. Both need to be taken into account.

“retrospective past actions”

Here’s what I’m thinking about. I’ve arrived here, now. Some future version of me travels to the past and changes my past. What happens to my memories? Am I still the same person I was before my past changed? Why would my future me go back into the past in order to change the present me, also changing the future me, perhaps in a way that I can’t go back to the past. So if I can’t go back to the past, I didn’t go back to the past, and my past was never changed.

Ok, we can try to trace all the what-ifs and play time travel games. Why? What do we get out of it? Is it merely entertainment, or do we actually learn something useful in the world as we know it, which does not include time travel?

Is this about the nature of identity? Is this about paradoxes? Is it about messing our heads? Is it about finding another way to alter our consciousnesses? What?

And looking forward—if we are to change ourselves in the past, then the future must already have happened because we don’t yet have a time machine. If we can travel through time, then all time must already be in existence. But if it is in existence, then our actions have already happened, and that means we can’t change them.

If the past and future have already happened, then when we went back to the past to change the future, we changed nothing because it had all already happened. But if we changed nothing, why do we think something was changed? What motivated our future selves to go to the past to make changes?

What the hell is the story here? Am I just juggling memes with a molten shoehorn? Yeah. Try to wrap your head around that one! Or is that being way too generous? And why do I bother? Why does anyone bother? Don’t we have better things to do with our time? Look. I’m flying in whiteout conditions, my altimeter is sinking dramatically no matter which way I pull the stick. I’m dizzy; I’m about to throw up; and I’ve got to be closing in on the surface of the ocean at an incredible clip.

Could someone please get me a drink?

<<offers @wundayatta a glass of ice water or bourbon>> What I am having most fun with these days is trying to imagine what my atoms were before I came about all the way to the beginning of time! It is a roller-coaster of “ooooh that would have been cool” to the not-so-cool versions.

It could be like “colorless green ideas sleep furiously.” The syntax makes sense, but the words don’t.

In terms of the paradox issue (we changed nothing because it had all already happened but why do we think something has changed, etc.), it really depends on relative perspective. If we are able, somehow, to move through time as we move through space, what happens to us becomes perceivably distinct from what happens to others who are not travelling as we are. It’s like setting a bomb off somewhere but getting on a plane and leaving before you’re blown up too. If you didn’t get on the plane, you’d suffer the same physical effects as others. But you left. Once you reach your destination, news about the bomb or physical effects from it have gotten there…but you had been removed so you haven’t been affected in the same way.

And if we’re talking about a future self trying to change the past, we can think of it in a single or multiple timeline scenario. If it’s singular, I’ve just removed myself from the timeline and returned at a point where the effect of what I’ve done can be felt. In that scenario, something would have happened that stopped me from existing, I existed in nearly the same way I did previously, or I’m noticeably different. In the cases where I was born – now there are two of me, I would think. So, we either coexist or I knew that I would be killing/eliminating the other me to take his place. My motivations are my own…I don’t change. Everyone else does.

In the multiple timeline situation – it’s the same except that in my original timeline, I disappear into the past never to return. And in the altered timeline, I come in at some point and it’s the same as the single timeline situation above.

It’s all about perspective. Relativity time experiments have shown us that traveling faster through space slows time for you (it’s like you’re sort of catching up to it). So time travel into the future is already possible, just not back.

I’m sure they could if it was possible, but I don’t think we can travel back in time.

I believe that at this point…there’s a scientific assumption that time travel to the past is possible but not yet – and time travel must be invented first.

So if it were “invented” tomorrow, I believe the theory is that every day after tomorrow would be able to travel back to tomorrow…but not any point in time before that.

I don’t believe that time travel is possible. If it were, however, travel to the past would have to take one of two forms. Peter van Inwagen has referred to these as the Ludovician and non-Ludovician models. The first involves a “stable time loop” in which you’ve “already” changed the past whether you know it or not. This implies a sort of determinist picture in which the effects of time travel have already affected the “first run” of history. The second involves the elimination of all time following the point back to which you travel. On this model, the very act of time travel destroys the future that once was, thus allowing us to be causally efficacious. Strictly speaking, however, I do not think this constitutes changing the past. It constitutes fundamentally changing the world such that the past never was (at least, that part of the past eliminated by act of the time travel).

This second model strikes me as even less likely than the first. It seems that the stable time loop model is more coherent if we want to say that we’re actually traveling to our own past and not to some alternate possible world that happens to share the same sequence of historical events up to a particular point (i.e., the point to which we travel). This is because van Inwagen’s non-Ludovician model has the consequence of only being sensible from an external perspective he refers to as “hypertime.” From this perspective, the destruction and reconstruction of the time line would be in some sense perceivable.

But if there were such a thing as hypertime, it seems that it would be the best actual candidate for time itself. Thus it would not be time but rather something else getting destroyed and reconstructed on the non-Ludovician model. What could that be? I’m not sure. If there is no sensible answer, then the non-Ludovician model is in serious theoretical trouble. If there is an answer, however, it would still seem that time itself is not actually being changed.

Let me see if I can explain this in simple terms. Retrospective past actions cannot change a future that has already happened because the future is past its causal point of inception in the cosmic causal ordering postulate (COP) does not allow tautologies to be run against God. If that seems difficult to grasp at first it is because I know you believe you understood what upi think I said, but I am not sure thay you realize that what you heard is not what I meant.

@SavoirFaire You are being too careless in your first sentence. Time travel isn’t just possible, it is common place. We travel forward in time every second. What is problematic is traveling to the past and traveling to the future at a faster than normal speed. Please try to be more careful in the future.

@SavoirFaire Oops! Good point. Don’t know what I was thinking.

The only explanation that I have heard that makes it possible to change something that has already happened is the multiple universe interpretation of quantum mechanics. In that case, what is done after traveling back in time spins off an entirely different world with its own history and has no impact on the original world.

The past is the and future are one…therfore the things that has been will occur again…
Everything that occurs in between is vain because it eventually leads to the future which is also the past.

We are already time travellers..because we see both the past and future…
And we escape time when we realise that they both are one…and at that point we also know that time exist within ourselves.

@kess

One is one.
Two is two.
I am one,
You are too.

And that’s why.