What if they just cut off Jenkin’s other ear?
I know I say this a lot, but this post really made me laugh. There are a lot of funny people on this site. If I laugh once a day at something, I am happy. 
Exactly: the experiment hasn’t been performed, and we don’t know. We don’t know the “rules” of alternate realities. We don’t have a working model of it to point to.
Small events might simply damp out and vanish. If I throw a two-pound stone into Lake Michigan, the water displacement will have disappeared entirely long before you get to Lake Huron.
“For want of a nail…the kingdom was lost” only seems to apply to shoes, horses, battles, and kingdoms that are right on the very knife-edge cusp of victory or loss. A small change of personnel at the defense of Bastogne in the Battle of the Bulge in 1944 might have changed the outcome of that city’s defense – but not of the overall battle, and certainly not of the overall war.
Most of the time, changing one single pebble’s position is unlikely to change anything. Does it really matter if you step on a brown pebble or a white pebble? In the long scheme of things, no. However, occasionally it does matter. The white pebble turns out to be a tiny shard of glass, which embeds in your foot and causes you to be late for work, for which your boss fires you and ultimately you’re living out of garbage cans on the street while somebody else has your job. Now, does it really matter to your ex-boss if you’re the one doing work for him or some other guy? In the long scheme of things, no.
There’s also the theory that changing something in the past will merely create an alternate, parallel timeline separate from your original timeline, which will remain unaffected no matter how crazy and divurgent the parallel timeline becomes. Here’s an intellectual dissertation on the subject.
Simple answer, actually.
Before you move get the chance to move the pebble, in fact, as soon as you step into the past, you negate your own existence. The universe then re-rolls all the quantum die again from that point forward, the chance of you existing and creating a time travel device is lower this time. If you keep trying again in the new timelines, the loop continues until the probability is zero, whether through your non-existence, or your disinterest in time travel. The universe works out the kinks until, while you could travel in time, you never do. (“you” being any time traveler, as you personal you will never exist, but that’s okay, neither will any of your friends or family.)
At least, I’m pretty sure that’s how the math works out.
hkepotat: a nice variation on “Niven’s Law.”
Niven says more or less the same thing, but from an intentionalist viewpoint. If one could change the past, one almost cannot escape desiring to. Save the Jews from the Holocaust; prevent the Trail of Tears; rescue the Library of Alexandria, etc.
Each of these changes changes all of history. Eventually, a time-line is created in which no one, by whatever rare chance, discovers the principles of time travel. That time-line is stable, but none of the others are.
The parts from that butterfly effect link that get missed are among the most important parts of Chaos Theory:
Those valleys are what Chaos Theory call “attractor basins” and part of the point is that while which valley the ball will end up can be possibly changed by slight changes in its initial position there are still a only a finite number possible valleys for the system to settle in to. And if the ball is already well on its way rolling into one of those valleys then changing which valley it ends up in would take a big change.
COULD that moment have been a moment on the fractal landscape cusp and the one pebble be something that rolls events into a different attractor basin? Possible. An ant takes a different path resulting in … who knows?
<Gasp!>
I just re-read this thread, and the whole thing is different than it was before!
I think that means that any intelligence, or anything that can have intent, can only exist in a unstable timeline.
Huh? How do you figure that? How does ordinary intent alter the past?
Having intent and being able to change the past defines (per Niven’s law) an unstable time line.
Just having consciousness, awareness, volition, or intent does no such thing.
I think this exchange captures the OP. I’ll note that Stephen Wolfram is not a climatologist. Do models of the weather commonly include terms that represent viscous effects, whatever they are?
I have a copy of Wolfram’s book. One that I haven’t really cracked. Until now! It seems (p. 972) that Wolfram thinks that in some cases “Sensitivity to initial conditions”, might be confused with “Intrinsic randomness”, Wolfram’s favored explanation. And from p. 998 I’ll quote:
[QUOTE=Wolfram]
The Lorenz equations represent a first-order approximation to certain Navier-Stokes-like equations, in which viscosity is ignored. And when one goes to higher orders progressively more account is taken of viscosity, but the chaos phenomenon becomes progressively weaker. I suspect that in the limit where viscosity is fully included most detials of initial conditions will simply be damped out, as physical intuition suggests.
[/QUOTE]
Perhaps that is the case. But this is conjecture and not the result of direct investigation. That said, wiki’s article on chaos theory has a section on distinguishing chaotic deterministic systems (where small changes in initial conditions lead to big changes) from stochastic or random systems (where each period contains a random shock).
The authors in this 1990 article say they’ve statistically distinguished examples of deterministic chaos, random processes and a combination of the two. http://deepeco.ucsd.edu/~george/publications/90_nonlinear_forecasting.pdf
Again, to my understanding, it depends on the specific chaotic system; “may be” highly sensitive to intial conditions does not mean always is.
The analogy is made rolling a die down a slope. It would be nearly impossible to have the intial conditions exact enough that the course of the die down will be the exact same any two throws, nevertheless you can state that a standard six sided die will have a one in six chance of landing on each one of the six faces, and that a loaded die is more likely to come up with that face up, even if the course that it takes to get there is different every throw.
Some chaotic systems are highly resistant to changes in initial conditions and will settle into specific attractor basins* even if every run results in a differerent path to get there*.
So what is the nature of the chaotic system that is human history? Does it have strong attractor basins? Is it a rolling a marble down a slope and prediciting what exact point of the marble will be facing up at bottom (no strong attractor basin, highly likely a tiny change in initial conditions will lead to a different result) or rolling a loaded die (strong atrractor basin, highly resistant to changes in intial conditions)?
We shouldn’t worry about reducing carbon emissions or taking carbon out of the atmosphere, all we have to do is move a pebble and the earth will start to cool down. Or perhaps things don’t work that way.
Agreed.
Natural fertilization is very likely too random to duplicate. Scientists have shown that certain types of sperm as more likely to fertilize an egg, but you’re still talking about one in millions upon millions chance.
Sometimes I daydream about time-traveling back into my own body Quantum Leap-style, but I have to recognize that while I may be able to date and marry the same woman, there’s virtually zero chance of having the same children. Even if I recreated the timing of conception as carefully as possible, I believe we’d have completely different kids.
I know you know the difference between weather and climate.
Weather may be (allegedly is) very sensitive to initial conditions; that in no way informs to climate.
Yes it was exagerrated, to make a point. I don’t buy that small perturbations result in large changes that readily. I’ll go with the viscous effect to make it simple. I’m talking about likelihood of what happens here, not whether or not it’s possible. I think it more likely the effects of moving a pebble are spread among a lot of valleys and in the end enough valleys end up with balls in them that the difference is barely distinquishable regardless of which ball fell in which valley initially.
Partly, you have to look at how likely particular events are going to be and how sensitive they are to changes.
For example, if an ancestor of GW’s narrowly survived being shot by an arrow on that path, moving the pebble could be the difference between life and death. Big difference there.
But it’s more likely that the pebble causes no real disturbance of events there. We deal with moving pebbles all the time and never even pay attention to them. This is where the consensus seems to break down. Either you believe in a positive-feedback system where a small change cascades into further changes until the results are dramatically different, or you believe in a negative-feedback system where a small change is lost in the background noise of the system and history continue pretty much unchanged.
What does paying attention have to do with anything?
Years ago I might not have paid attention to whether or not my shoe was tied, but if I had noticed it was not and stopped to tie it I would have entered a dance at a slightly different moment, and noticed a different young woman to ask to dance, never developing a relationship with the woman who became my wife and with whom I have four very specific children, each of who have and will impact the universe in slightly different ways … the exact moment I entered a room was the result of many “pebbles”, any of which could have caused me meet or not meet that woman and say whatever it was that got her to dance with me despite my untied shoe, which then altered the path of my life and caused certain lives to occur, and presumptively others to never occur. Certain cars took other paths because I was at the intersection. Accidents may have happened had I not changed the traffic flow; some may have occured because I did. The changes in the exact flow of events, in who gets born and who dies, become huge. The exact shape of history is likely different in many ways as the result of every small change. My suspicion is that the overall shape is still pretty much the same. Sort of like those fractal landscape generators: no two runs will produce the same result but the overall landscape being clearly “mountain” or “pasture” is still pretty predictable.
Is it fair here to point to geographic and technological determinists? Those who say that England and Japan “had” to become naval powers, or that the steam engine “caused” capitalism?
(I subscribe to the “weak” variety of these views, that geography and technology sort of “tilt the balance” in those directions, much like your weighted dice example. A weighted die doesn’t always turn up a six, it just does so more often than it should.)
In Gleick’s book “Chaos,” he tells of explaining chaos and the butterfly effect to someone, who instantly leapt to that conclusion. “This means weather control!”
In abstract theory, the “strong” butterfly effect idea would mean weather control – once we develop enough computational power to know which pebble to move!
(As above, I favor a “weak” version of the idea instead. Most days, moving a pebble results in no larger-scale changes at all.)
Epiktistes might not like that. 