stevearico wrote:Have you had a similar discussion with someone called Stevo1361 on google+ late last year? Because the way you write is familiar. If you have then that's me!
I'm pretty sure it wasn't me, at least I don't remember having any discussions on google+ last year.
stevearico wrote:JesseM wrote:But the bootstrap paradox is not actually a "paradox" in terms of being logically inconsistent, only in terms of being counterintuitive. Kip Thorne suggests in his work that if time travel turns out to be possible, we might actually expect bootstrap-paradox type situations involving billiard balls as having some real physical likelihood in a scenario where we shoot a billiard ball towards a wormhole. Just consider the third scenario from the diagram I posted
here, where the billiard ball's initial trajectory is such that if left undisturbed it won't travel into the wormhole at all, but then its future self comes out and deflects it at just the right angle so it can go into the wormhole and become that same future self.
Fair enough, i don't have an issue with the billiard ball scenario or thought experiments where the future influences the past in a cyclical loop. Where i have an issue with Interstellar and why i don’t think it fits the billiard ball theory is that the wormhole existing is reliant on beings who we are led to believe will die should they not be able to follow the sequence of events which we see unfold.
But beyond just the future influencing the past in a cyclical loop, are you saying that you're OK with some types of scenarios where the nature of the loop is such that, if the past self hadn't gotten that influence from the future, they never would had the opportunity to travel back in time at all? Because that's basically what's happening with the third billiard ball diagram I was referring to--again, the billiard ball is on a trajectory that would cause it to miss the wormhole altogether, and we can make it even more analogous by imagining that directly on its path is a bomb that will destroy it as soon as the billiard ball collides with it, so without any intervention from the future it's doomed just like humanity was in Interstellar. But then its future self pops out of the wormhole and deflects it away from the bomb and into the wormhole, then when it goes through the wormhole it becomes that same future self, in a self-consistent loop which not only explains why it went back in time but also saves it from destruction. So I just want to make sure that you don't have a problem with this, and that the only thing that bothers you is the appearance of the wormhole itself (or the tesseract later in the story) in what "They" would view as the distant past.
Or we could also imagine a different story similar to Interstellar, where in the 21st century humanity is dying, and then suddenly a wormhole appears in our solar system. But let's say that in this story--similar to an earlier draft of the Interstellar script, and also similar to Carl Sagan's novel Contact--this wormhole was built by a long-gone alien civilization billions of years in the past, and it's just one member of a huge network of wormholes connecting many star systems across the galaxy. So imagine humanity uses the wormholes to escape extinction and colonize the galaxy, until finally after centuries of exploring this wormhole network, they discover a wormhole that leads centuries into a past, to a time hundreds of years
before the 21st century when humanity discovered the first wormhole. However, this wormhole takes the future humans to a star system far away from Earth, and by training their super-telescopes on Earth, they see there is no wormhole in our solar system at this date. So knowing that humanity is going to need saving in a few hundred years, they find another wormhole nearby (which like all the others was created long ago by aliens) without a time delay between the two mouths, and they physically tow one mouth of this wormhole towards our solar system, while towing the other mouth to the star system that history records was the first one humanity visited. The mouth being towed towards the solar system arrives in the 21st century, just in time for humanity to discover it and escape extinction.
So in this story, just like in Interstellar, humanity would have gone extinct if not for the intervention of our future selves. But in this case, the intervention is that our future selves brought a preexisting wormhole into our solar system, not that they actually created a new wormhole (or a new tesseract, since it's that rather than a conventional wormhole that enables time travel in Interstellar) in their own past that wouldn't have existed without their intervention. So would the story above seem OK to you, and it's just the creation of
new spacetime shortcuts in the past that bothers you?