: I don't have time to get into this tonight - I have an early morning meeting.
: The one major problem I have with your theory of time travel and branching
: timelines is that, even if you do go back and create your own universe
: that has the outcome you desire, someone else can go back and create one
: with a very different outcome. So there you are - a copy of you in your
: ideal universe, and a duplicate in a less-than-ideal universe. So maybe
: your double decides to go back and interfere yet again, completely unaware
: that there is already an ideal universe out there in which you're content.
: Multiply all of this by the number of entities with the ability to time
: travel and the number of times they do so and you end up with a hell of a
: lot of different timelines out there. It makes for interesting science
: fiction, but it's only fiction. There has to be some logical, physical
: limit on this to make it believable. Perhaps each branch point creates not
: a new timeline, but rather a finite time loop. These loops must be limited
: (perhaps something about conservation of matter and energy) and at some
: point they either end, join back with the main timeline or become the main
: timeline. Forrest, I leave it to you to come up with your own practical
: approach.
The way the "many worlds" interpretation of quantum physics has it (which is what most physicists buy today), there are already an infinite number of timelines, regardless of whether time travel is possible or not. Every given instant, all the possible outcomes of all quantum states, multiplied together, happen. (Say for instance that there were only 8 variable bits of the universe, each with only two possible states - every instant, you'd have 256 distinct possible outcomes).
Many essentially identical parts of total universal states happen multiple times (similar to how a quadratic or higher polynomial equation can have multiple roots, some of which recurr; or how a number can have a given prime as a factor more than just once) - and thus those highly-recurring resultant states are more likely and the ones we "usually" find ourselves in. The resultant state that myself from the future suddenly appears right next to me has, by modern understanding of physics, a likelyhood of zero.
All I've done science-fiction hand-waving-magic wise is postulate that the Jjaro discovered some means by which, ultimately, zero-likelihood probabilities can be made so. Want to create a gravity field? Presto! Want to be in the past? Presto! That part is magic, something not understood to be possible to us here today; but the physics of how timelines would function IF that were possible are easily derived from modern, well-demonstrated physical principles.
And that's ultimately what science fiction (or really, all speculative fiction) is all about - given what we know about reality, if {speculation} were also to be so, then what would happen? If we had big rockets that could push us to the moon, what would we do? If people could jack into computers and upload/download memories, then what would we do?
If I were a superhuman cyborg with some device in me that let me travel time, but nobody except a bunch of crazy artificially intelligences understood how to use it, what would I do?
