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The actual Butterfly Effect sometimes gets me thinking. Unlike what's popular in time travel fiction, it seems to me that even the tiniest change would cause a

by anyfoo 7y ago

The actual Butterfly Effect sometimes gets me thinking. Unlike what's popular in time travel fiction, it seems to me that even the tiniest change would cause a completely different world, with completely different people inhabiting it, about a generation or so deeper. As a stupid example, consider the change being a tree branch falling in the Serengeti. A small animal, which would otherwise have just continued eating, scuttles away. It crosses a nearby road, causing a nearly imperceptible slowdown for a woman on here way to the airport. She arrives just a few seconds later, but it's enough for the pattern of people in the hall to change and her to not see a sandwich shop she would have seen at a glance. She arrives meeting her husband, sleeps with him just like in the original timeline--but because she's slightly more hungry, did slightly different things on the plane, and so has slightly different discussions, they sleep with each other a tiny bit earlier or later, in an ever so slightly different position, but completely enough to either not cause conception of the child they would have conceived originally, or the conception of a different child (different sperm, different combination of genetic material, and so on). And now it's obvious. The child is essentially a completely different person, with completely different thoughts, actions, being not exactly where the original child would habe been throughout its life at practically all moments (even if they go to the same school, they're unlikely to stand in the same spot in the hallway at all times). Blocking other people's view, or slowing them down, or causing them to go somewhere else. Causing many many "tree branches" of its own, many of which result in people meeting or not meeting other people, or having different offspring regardless, and so on. Now, consider that this was just looking at one consequence of the falling tree branch. There are many more. The point is, it can be the tiniest things that ripple through time to entirely change who is populating earth a few decades later. In media, even when the change is "prevent World War II", today's world almost always gets portrayed with the same characters and same personalities, that somehow still all met. I don't blame the writers, though, it certainly makes for a more entertaining story.

hanoz 7y ago
Absolutely, the butterfly effect renders all back in time plots fatally flawed. Never mind killing Hitler's grandfather or making sure your parents still meet, your very appearance in an earlier world, even for an instant, would guarantee that before long you and everyone else who would otherwise have been born afterwards would certainly never exist.
- EGreg 7y ago
  Not in Gargoyles
- ModernMech 7y ago
  I saw a drama based on Steven King's 11/22/63. A guy goes back in time to save JFK from assassination. Spoiler: he saves JFK in the past and when he finds his way to the future the world is destroyed. Oops.
- vidarh 7y ago
  This presumes a variant of time travel that allows changes to make a difference. A many world interpretation would just mean branches (and you'd only see your changes if you manage to find a way to navigate to them); a fully deterministic model would imply you can't change anything and your time travel always had happened exactly the way it would happen, and whatever you think you achieved was consistent with history (wasn't really Hitlers grandfather after all for example); a strongly convergent model would see the effects mostly have relatively minor effects, and when they tip over and have bigger effects, those bigger effects still end up cancelling out over time. We both don't know how time travel would work if it is possible, and don't know well enough what the odds are of any small change affecting large long time change. E.g maybe if Hitler didn't come along, someone else would have. And in fact, exploring those effects is often a major part of back in time plots. Moorcocks 'Behold the man' for example have someone travel back in time to meet Jesus only to realise that the real Jesus was a mentally disabled man and that since he is the only one that knows the image of present day Jesus, the time traveler himself must always have been the person history knows as Jesus, presenting a deterministic idea of time, where paradoxes would be impossible, because time is in that world in effect just one more spatial dimension our perception moves across. There are many such models that would allow for some time travel plots to be plausible all the time we have no idea how it actually works. Of course all of them will probably look quite ridiculous and quaint if we ever figure out the real thing.
baddox 7y ago
How could we estimate how resilient the timeline is to small changes? If no small animal had been in the vicinity of the falling tree, perhaps that event would be much more insulated from humans.
- anyfoo 7y ago
  I think it's a good question. Let's assume there is absolutely no animal nearby (tree branch makes a sound, slightly changing any animal's behavior, chain reaction...), and let's further assume that the tiny air currents generated in this scenario do not only not cause a tornado as in the original butterfly effect (which, frankly, is not very likely), but are "buffered" enough that they don't create any change perceptible to any human at all. Then, overall, the makeup of the world is still different. Will this really never cause anyone to get a speck of dust in their eye that they otherwise wouldn't, flinching, preventing them from having the though "oh I have to buy milk" that they were about to have? I don't know... maybe it's just that some changes are indeed so tiny and remote that it takes them a long long time to have an effect, but once an obvious effect is present, I guess we're back to everything changing again?
  - hanoz 7y ago
    > let's further assume that the tiny air currents generated in this scenario do not only not cause a tornado as in the original butterfly effect (which, frankly, is not very likely) You're underestimating the effect now. You only have to play about with a simple chaotic function and see how quickly the most infinitesimal change leads to utterly different results to appreciate that a butterfly flapping its wings sufficiently in advance literally alters the course of all subsequent tornados. If your home had a 99% chance of making it through tornado season unscathed one year but for the flap of a butterfly's wings, then it may still have a 99% chance, however it would be a completely new role of the dice.
    - foldingmoney 7y ago
      But you're assuming the world is a chaotic function. Don't confuse the ability to add up tiny changes with those changes having a meaningful impact. You can dip your finger in a river and tell me how a bunch of molecules are displaced and then those molecules displace other molecules and so on in a way that wouldn't otherwise have happened. But for all intents and purposes, the river carries on in its original course as if nothing happened. It doesn't turn into a seething mass, it doesn't reverse course, it doesn't spiral off into infinity. Sensitivity to initial conditions is relatively rare, and even most chaotic functions only get interesting around certain values.
drewrv 7y ago
The short story "Anxiety is the Dizziness of Freedom" has an interesting take on this theme, where the many worlds interpretation of quantum mechanics is true, and a device lets people communicate with parallel realities. They start off with a difference of one quantum measurement but slowly diverge.
GistNoesis 7y ago
Sure the world will be completely different, but in high likelihood it will be very similar. To take your examples, the kid born might be completely different, but will likely receive a somewhat similar education that it would have so he won't be too different. Wars that might have been avoided on one occasion might just have been delayed, (WW1 ferdinand assassination comes to mind). In chaos theory, the space of possibilities is usually split up in different regions called basins that each converge towards around its own attractor point. But usually a small change isn't enough to make you change of basin. It only matter when you are close to the boundary, on the edge of chaos. It's kind like re-rolling when playing D&D, you can get luckier and win the fight instead of losing it, but if you are not well prepared it won't matter in the long run. At scale, the law of large numbers average effects out. In science-fiction the theme of order vs chaos is often evoked, because it's one of the most powerful tool for the underdog hero to turn the situation around. By definition the hero must choose the more risky side and chaotic situation that will give him his only chance to get out on top.
- anyfoo 7y ago
  How can the world be "very similar" if it consists of an entirely different set of people within a relatively short time? Think about it, if not a single one of the politicians, inventors, scientists, or really any plain regular person would have existed. If any tiny change does not stay in complete isolation (which I don't think is physically possible), eventually the world will be entirely different. Even language will completely diverge.
  - Retric 7y ago
    The weather patterns, infrastructure, and economic constants are going to be nearly identical. Roll back the clock 2,000 years and you would still see major cities mostly at the same rivers and ports. Major inventions often have several people making the same basic discovery at the same time. You can’t build heavier than air controlled flight without efficient engines. You can’t build efficient engines without high precision manufacturing. Which requires it’s own constraints etc. Replay the last 30 years and Dell might not have been the mail/phone then internet order PC vender to become a household name. But, one of them would because several where trying and efficiency of scale is a major advantage. PS: One if my favorite examples is in a high school science class I was messing around with a power supply and mechanical pencil lead. It ended up making a rather bright light, in a moment of wonder I realized I had become possibly the millionth person to discover a precursor light bulb. Well over a hundred years late by on measure but in terms of the 100,000’s of years history of humanity fairly close.
cortesoft 7y ago
It depends on what theory of time travel we are talking about. If we have the multiverse theory, then you are just creating a new split in the possible timelines. Other theories would say that your time travel has already been taken into account in the timeline, so anything you are doing to change the future will actually cause it to happen as it has already happened.
gregmac 7y ago
You could extend this further: what if we could "rewind" time, then just let things play back again. Would everything be exactly the same as it is now? Would "random" particle interactions happen in the same way (making them decidedly not random)? Would the same branch fall at the same time, landing in the same place? Would every coin flip be the same? Would every single decision every human makes be the same?
- anyfoo 7y ago
  Since rewinding time is entirely theoretical, and assuming physicalism, I guess that entirely depends on whether, in your thought experiment, you allow quantum interactions (those which are posited to be truly random) to play out the same way or not. If yes, yes, if not, not. 8)
seventhtiger 7y ago
I've had the same thought before. In response to the question "if you go back to being a child knowing what you know now, what would you do?" Being the eldest I thought I would immediately cry for my unborn siblings who are now just an unrealized possibility.
scarejunba 7y ago
Well, go ahead and try it out. Have you and a friend leave slightly differently from your homes in San Francisco to go see another friend in San Jose. You leave ~ 10 mins from each other and you'll arrive ~ 10 mins from each other. You'll encounter similar traffic. Go ahead and test the way your world works. The short term doesn't matter. It gets beaten by the weight of other stuff.
foxyv 7y ago
Choas is kinda funny. When you have systems of a large number of non-linear things they tend to average out. A time traveler could be as little as a single particle and still re-shuffle the entire deck so to speak. But it's still the same deck of cards. In the end you're still in nearly identical initial conditions. While the individuals will change, the whole of society will be extremely similar due to statistical mechanics. Susie being slightly more aggressive will be balanced out by Johnny being slightly less aggressive, etc... You may cause a new extrema event though like Johnny inventing a cheap nuclear bomb, or you may prevent one. A good time traveler would be able to sit outside time and probe reality using tiny changes until they get the outcome they want. But at that point you are so powerful I can't imagine anyone would care. Maybe that's why we didn't all kill ourselves yet. Some time traveler poking at the timeline.

by anyfoo 7y ago

hanoz 7y ago

Absolutely, the butterfly effect renders all back in time plots fatally flawed. Never mind killing Hitler's grandfather or making sure your parents still meet, your very appearance in an earlier world, even for an instant, would guarantee that before long you and everyone else who would otherwise have been born afterwards would certainly never exist.

EGreg 7y ago
Not in Gargoyles
ModernMech 7y ago
I saw a drama based on Steven King's 11/22/63. A guy goes back in time to save JFK from assassination. Spoiler: he saves JFK in the past and when he finds his way to the future the world is destroyed. Oops.
vidarh 7y ago
This presumes a variant of time travel that allows changes to make a difference. A many world interpretation would just mean branches (and you'd only see your changes if you manage to find a way to navigate to them); a fully deterministic model would imply you can't change anything and your time travel always had happened exactly the way it would happen, and whatever you think you achieved was consistent with history (wasn't really Hitlers grandfather after all for example); a strongly convergent model would see the effects mostly have relatively minor effects, and when they tip over and have bigger effects, those bigger effects still end up cancelling out over time. We both don't know how time travel would work if it is possible, and don't know well enough what the odds are of any small change affecting large long time change. E.g maybe if Hitler didn't come along, someone else would have. And in fact, exploring those effects is often a major part of back in time plots. Moorcocks 'Behold the man' for example have someone travel back in time to meet Jesus only to realise that the real Jesus was a mentally disabled man and that since he is the only one that knows the image of present day Jesus, the time traveler himself must always have been the person history knows as Jesus, presenting a deterministic idea of time, where paradoxes would be impossible, because time is in that world in effect just one more spatial dimension our perception moves across. There are many such models that would allow for some time travel plots to be plausible all the time we have no idea how it actually works. Of course all of them will probably look quite ridiculous and quaint if we ever figure out the real thing.

baddox 7y ago

How could we estimate how resilient the timeline is to small changes? If no small animal had been in the vicinity of the falling tree, perhaps that event would be much more insulated from humans.

anyfoo 7y ago
I think it's a good question. Let's assume there is absolutely no animal nearby (tree branch makes a sound, slightly changing any animal's behavior, chain reaction...), and let's further assume that the tiny air currents generated in this scenario do not only not cause a tornado as in the original butterfly effect (which, frankly, is not very likely), but are "buffered" enough that they don't create any change perceptible to any human at all. Then, overall, the makeup of the world is still different. Will this really never cause anyone to get a speck of dust in their eye that they otherwise wouldn't, flinching, preventing them from having the though "oh I have to buy milk" that they were about to have? I don't know... maybe it's just that some changes are indeed so tiny and remote that it takes them a long long time to have an effect, but once an obvious effect is present, I guess we're back to everything changing again?
- hanoz 7y ago
  > let's further assume that the tiny air currents generated in this scenario do not only not cause a tornado as in the original butterfly effect (which, frankly, is not very likely) You're underestimating the effect now. You only have to play about with a simple chaotic function and see how quickly the most infinitesimal change leads to utterly different results to appreciate that a butterfly flapping its wings sufficiently in advance literally alters the course of all subsequent tornados. If your home had a 99% chance of making it through tornado season unscathed one year but for the flap of a butterfly's wings, then it may still have a 99% chance, however it would be a completely new role of the dice.
  - foldingmoney 7y ago
    But you're assuming the world is a chaotic function. Don't confuse the ability to add up tiny changes with those changes having a meaningful impact. You can dip your finger in a river and tell me how a bunch of molecules are displaced and then those molecules displace other molecules and so on in a way that wouldn't otherwise have happened. But for all intents and purposes, the river carries on in its original course as if nothing happened. It doesn't turn into a seething mass, it doesn't reverse course, it doesn't spiral off into infinity. Sensitivity to initial conditions is relatively rare, and even most chaotic functions only get interesting around certain values.

drewrv 7y ago

The short story "Anxiety is the Dizziness of Freedom" has an interesting take on this theme, where the many worlds interpretation of quantum mechanics is true, and a device lets people communicate with parallel realities. They start off with a difference of one quantum measurement but slowly diverge.

GistNoesis 7y ago

Sure the world will be completely different, but in high likelihood it will be very similar. To take your examples, the kid born might be completely different, but will likely receive a somewhat similar education that it would have so he won't be too different. Wars that might have been avoided on one occasion might just have been delayed, (WW1 ferdinand assassination comes to mind). In chaos theory, the space of possibilities is usually split up in different regions called basins that each converge towards around its own attractor point. But usually a small change isn't enough to make you change of basin. It only matter when you are close to the boundary, on the edge of chaos. It's kind like re-rolling when playing D&D, you can get luckier and win the fight instead of losing it, but if you are not well prepared it won't matter in the long run. At scale, the law of large numbers average effects out. In science-fiction the theme of order vs chaos is often evoked, because it's one of the most powerful tool for the underdog hero to turn the situation around. By definition the hero must choose the more risky side and chaotic situation that will give him his only chance to get out on top.

anyfoo 7y ago
How can the world be "very similar" if it consists of an entirely different set of people within a relatively short time? Think about it, if not a single one of the politicians, inventors, scientists, or really any plain regular person would have existed. If any tiny change does not stay in complete isolation (which I don't think is physically possible), eventually the world will be entirely different. Even language will completely diverge.
- Retric 7y ago
  The weather patterns, infrastructure, and economic constants are going to be nearly identical. Roll back the clock 2,000 years and you would still see major cities mostly at the same rivers and ports. Major inventions often have several people making the same basic discovery at the same time. You can’t build heavier than air controlled flight without efficient engines. You can’t build efficient engines without high precision manufacturing. Which requires it’s own constraints etc. Replay the last 30 years and Dell might not have been the mail/phone then internet order PC vender to become a household name. But, one of them would because several where trying and efficiency of scale is a major advantage. PS: One if my favorite examples is in a high school science class I was messing around with a power supply and mechanical pencil lead. It ended up making a rather bright light, in a moment of wonder I realized I had become possibly the millionth person to discover a precursor light bulb. Well over a hundred years late by on measure but in terms of the 100,000’s of years history of humanity fairly close.

cortesoft 7y ago

It depends on what theory of time travel we are talking about. If we have the multiverse theory, then you are just creating a new split in the possible timelines. Other theories would say that your time travel has already been taken into account in the timeline, so anything you are doing to change the future will actually cause it to happen as it has already happened.

gregmac 7y ago

You could extend this further: what if we could "rewind" time, then just let things play back again. Would everything be exactly the same as it is now? Would "random" particle interactions happen in the same way (making them decidedly not random)? Would the same branch fall at the same time, landing in the same place? Would every coin flip be the same? Would every single decision every human makes be the same?

anyfoo 7y ago
Since rewinding time is entirely theoretical, and assuming physicalism, I guess that entirely depends on whether, in your thought experiment, you allow quantum interactions (those which are posited to be truly random) to play out the same way or not. If yes, yes, if not, not. 8)

seventhtiger 7y ago

I've had the same thought before. In response to the question "if you go back to being a child knowing what you know now, what would you do?" Being the eldest I thought I would immediately cry for my unborn siblings who are now just an unrealized possibility.

scarejunba 7y ago

Well, go ahead and try it out. Have you and a friend leave slightly differently from your homes in San Francisco to go see another friend in San Jose. You leave ~ 10 mins from each other and you'll arrive ~ 10 mins from each other. You'll encounter similar traffic. Go ahead and test the way your world works. The short term doesn't matter. It gets beaten by the weight of other stuff.

foxyv 7y ago

Choas is kinda funny. When you have systems of a large number of non-linear things they tend to average out. A time traveler could be as little as a single particle and still re-shuffle the entire deck so to speak. But it's still the same deck of cards. In the end you're still in nearly identical initial conditions. While the individuals will change, the whole of society will be extremely similar due to statistical mechanics. Susie being slightly more aggressive will be balanced out by Johnny being slightly less aggressive, etc... You may cause a new extrema event though like Johnny inventing a cheap nuclear bomb, or you may prevent one. A good time traveler would be able to sit outside time and probe reality using tiny changes until they get the outcome they want. But at that point you are so powerful I can't imagine anyone would care. Maybe that's why we didn't all kill ourselves yet. Some time traveler poking at the timeline.