No, when it comes to real-life physics, alternate timelines theoretically emerge from quantum events and have jack-all to do with human decisions. But in fiction, the concept of parallel timelines is interpreted in the context of decisions and macroscopic outcomes as a storytelling device.
And I submit in real life as well. Your quantum splitting, again, is a
mechanism by which timelines are spawned. It is not in itself the
cause of new timelines.
Yes, it is. Read the FAQ I linked to above. Contrary to how it's used in fiction and misinterpreted by the public, the "Many Worlds Interpretation" (more formally, the relative state formulation) is intended simply as an explanation for the appearance of wavefunction collapse upon the measurement of a quantum particle. It's about why a particle that exists in a superposition of multiple states appears to resolve into a single state upon measurement or interaction. The idea is that the act of measurement causes the states of the particles in the measuring device, the scientist doing the measuring, and everything else in the interconnected system to correlate with the states of the particle being measured. So the measuring device and the system it belongs to aligns into two (or more) sets of states -- one correlated with one of the states of the quantum particle, the other correlated with the other state (and so on if there are more than two states). Each set of correlated states represents a distinct measurement history that is non-interactive with the other. Thus, an observer in each relative state measures only one of the particle's states, and so it appears to the observer that the particle's wavefunction has "collapsed" into only one state, producing the appearance of classical physics.
That's what the MWI really says. Everything else about parallel realities and human decisions and so forth is accreted onto it by philosophers and writers of fiction.
You claim that timelines splitting as a result of character choice is a "conceit". Nothing could be farther from the truth.
I'm sorry, you're profoundly wrong. You're mistaking a conceit of fiction -- that decisions cause timeline splits -- with actual physics. Hugh Everett was not speaking of philosophy or cosmology or human history. He was offering a mathematical, physical explanation for the paradox of wavefunction collapse. If you'd make the effort to read the source I linked to above, you'd see that. Here it is again:
http://www.hedweb.com/manworld.htm
It's a very good primer on the MWI and what it really means. I drew on it a lot in writing
Watching the Clock; it really helped me understand quantum physics and the MWI better than I ever had before. You really should study it before continuing this discussion. Here are some other references I used:
http://arxiv.org/abs/quant-ph/9709032/ (a bit technical)
http://www.ipod.org.uk/reality/reality_decoherence.asp
History cannot "make itself". People make history, by making choices and acting on them.
Of course they do. But my point is that that's an
entirely separate question from the physics of timeline divergence. You're buying into the conceit of fiction that parallel timelines are a matter of history and choice, but that's not what Everett conceived them to be. So you're completely misunderstanding what it is I'm saying. You're treating the discussion of historical outcomes and the discussion of the MWI as if they were the same topic, but my whole point is that they aren't really, that fiction only pretends they are because writing stories about personal choice and the paths a society can take is more interesting than writing stories about whether a proton is measured as spin-up or spin-down.
Rome, for example, did not fall because of a quantum split.
Which is exactly my point -- that the topic of MWI and quantum splits is entirely separate from the topic of why historical processes occur. If quantum processes split the universe into 5000 parallels during the fall of Rome, then Rome would've fallen the same way in all 5000 of those parallel timelines, because the changes in the quantum states of particles would've had no bearing on the macroscopic, classical (no pun intended) processes that led to human decisions and cultural trends. So the quantum divergence would indeed have had no bearing on the historical choice.
But maybe, if there was someone whose mind was evenly split about a given decision at the moment the timeline happened to diverge, then there's a chance that one of the divergent copies might make a different decision than the others. And that could lead to one or more of those 5000 quantum timelines turning out measurably different from the others. The quantum divergence would not have caused the changed decision, no, but it would've created the
opportunity for both decisions to be made.
No, I'm pointing out that Everett is only looking at mechanisms, not causes. To suggest that history is changed by the act of spontaneously splitting quanta is to suggest an effect without a cause, which is not possible even in temporal physics.
But again, that is NOT what I'm suggesting at all. You're the one who's mistakenly assuming that fiction is correct in treating the topic of quantum timeline divergence as equivalent to the topic of human-scale history. What I'm saying is that they're two separate conversations altogether.
There MUST be a cause somewhere for any event within conventional reality (which would include the concepts of alternate timelines).
But you're conflating the quantum with the classical there. "Events" on the human scale, decisions and historical processes, are macroscopic, classical phenomena. Their outcomes are not, as a rule, determined by events on the quantum level of single particles. MWI is talking about quantum-level processes and is not meant to apply to classical, macroscopic issues like human history and choice. Fiction merely subverts the concept, makes it about those things as a plot device.
Who is positing there is no reason to favor one option over another? I'm certainly not. Whether or not I "favor" one decision over another at any given time is entirely under my control. In another timeline, under different conditions, my "twin" might favor another option based on his time, place, and circumstance.
Sure,
if the timelines diverged a significant length of time
before the moment of decision, so that the circumstances would be different. But that's not what I'm talking about. I'm talking about the conceit of fiction that every moment of decision
causes the universe to split
at that moment. I'm objecting to the class of alternate-timeline stories that assumes that every decision
generates as many different universes as there are possible outcomes of that decision -- that for every universe where the driver chooses to turn right, there
must be a universe where she turns left, as though there were no reason for that decision and it was just random which universe the story happens to follow. The assumption there is that everything is exactly identical up until the moment of decision is reached, and that at the very moment the driver begins to turn,
that's when the universe splits into two, one where the driver goes right and one where the driver goes left. Or into three if the driver can go straight. Or into as many different universes as there are possible outcomes. That's the model that ignores the influence of earlier causes and circumstances, that reduces all decisions to coin flips.
1) I am not identical to the me that makes choice B. The very act of chosing a over b makes me different from him.
But again, the whole premise of the fictional model I'm objecting to is that it's the moment of choice that
creates the split in timelines, so that there is only one single you up until you make that choice, only one single set of circumstances, and yet the decision causes the universe to split into one where you make choice A and one where you make choice B. From what you're saying, I think you object to that idea as much as I do, but you're just misunderstanding what it is I'm talking about.
Never said that either. What I said was, that for purposes of consequences and to the issue of whether or not the existence of infinite alternate possibilities negated the value of choosing or mitigated the consequences of choosing, the alternate realities didn't matter, as I was not there. I was where I was, and barring intervention, I would remain there.
But this isn't about you. It isn't about anyone who lives in the real world. As I've already said, your analysis applies to discussing real life, but I'm not talking about real life. I'm talking about fictional universes in which alternate timelines are real and accessible. So logic that makes sense in the real world, where alternate histories are by definition inaccessible and effectively nonexistent, doesn't apply to the kind of fictional universe I'm talking about. The rules of the universe can be different in fiction, and so the same arguments don't necessarily work there.
Only AFTER he became embroiled in them and interacted with them, thus making them part of his own personal timeline.
Yes, and that is my whole point. I'm talking about
stories in which crossovers between timelines are a directly experienced reality.
He never made any decision about running the station, or relating to his son based on what Mirror Jennifer might possibly say or think. They existed or not in their timeline, and he in his. For him, until he went to the MU himself they in fact were abstract, and had no bearing on him or his life in his own universe.
Not everyone could dismiss the question as casually as you claim you can. There are plenty of people of a more philosophical bent, people who would drive themselves crazy struggling to cope with the certain knowledge that they had parallel selves whose lives had different outcomes. Heck, I've spent time wrestling with that question myself, trying to ponder the philosophical and personal implications of having parallel selves, trying to understand why I would perceive myself in this branch rather than one of the others, etc., and it's rather daunting. And if I knew for a fact that there were a universe out there where my life was much better than it is here, it would be very depressing. You may be able to glibly dismiss it as irrelevant, but not everyone is you.
Human beings are decidedly NOT "meat puppets". Human beings have shown time and again that they can act beyond the bounds of their initial "programming". The most venal and selfish person can have a change of heart and demonstrate acts of charity. A coward can find his courage.
Related to that is the fact that people don't always do "what the dice tell them" they should do. The fact that not all people act in exactly the same way even under similar circumstances demonstrates that.
That's all entirely true, but the key is that it happens on a classical level, shaped by macroscopic processes in the brain and in the external world. So it's a separate phenomenon altogether from what the Everett interpretation is talking about, except in fiction where MWI is conflated with classical processes of history and choice.
On another matter, I do not claim that a new timeline only comes into being when it is perceived. Existence is not a matter of perception.
Well, that comes down to a misunderstanding of what a "timeline" really is. What we call a "timeline" in vernacular is really just a set of measurements of the state of the universe. When you measure a particle that's in two states at once, your measuring device, you yourself, and the system you occupy all end up in two states at once, one correlated with each of the particle's states. It's all still really one single set of particles, but it's in two separate sets of correlated states that behave as if they were distinct realities because they don't interact or affect each other.
So no, existence is not a matter of perception, but
which existence you observe is, by definition, a matter of perception. Although it would be more accurate to say that perception is merely one case of
interaction, which is what's really important here. It's the interaction between particles that correlates their quantum states with each other. Observation, measurement by a human being, is one type of interaction, and the one that gets focused on by scientists because science is about reporting the results of observation and experiment. This leads to the common misconception that "perception creates reality," but it's really all about interaction and correlation.
If by that you come to the conclusion I am not a fan of Schrodinger's Cat, you would be right. The entire concept is nonsense. The cat either is or is not in the box as a factual matter. My inability to see into said box affects that not one bit.
It's
supposed to be nonsense. The biggest myth about Schroedinger's Cat is that Schroedinger was saying it would really happen. On the contrary, he was saying that it
couldn't happen. His point was that quantum physics led to an irresolvable paradox and thus it was flawed, or at least incomplete. Schroedinger's Cat illustrated the clash between the multiple states of quantum-level particles and the observed reality that classical, macroscopic objects and events only happened one way. The question was, how do we resolve this? Where does the transition between quantum behavior and classical behavior occur, and why? Why
doesn't the dual state of the radioisotope result in a dual alive/dead state for the cat?
And the Everett Interpretation/MWI is an explanation for that exact question. The answer, according to it, is that the switch that triggers the poison capsule -- essentially a measuring device for the radioactive atom -- itself enters into a dual state, each one correlated with one of the states of the atom. And thus so does the cat, the observer, and everything else interacting with them. So there are two distinct measurement histories, one in which the cat lives and the observers are happy, one in which the cat dies and the observers get in trouble with the Humane Society. Since these measurement histories do not interact, they effectively form separate "universes" or "timelines."