You can certainly imagine going faster than light, but that doesn't mean it's possible. Saying it could be possible is basically saying "our understanding of physics could be wrong". Technically correct, but at that point we aren't having a productive discussion. "Assume everything we understand is wrong -> we can now teleport"
Does it even have to be teleporting to break causality, to be honest? Given a long enough journey, wouldn't the Alcoubiere (sp?) drive accomplish the same thing? By making a warp bubble and folding space using gravitational forces, none of the laws of physics are broken and the user can still move faster than the speed of light (though it isn't possible due to the lack of anti gravity, which might not exist - so there's that).
It doesn't have to be teleporting. Any superluminal travel can break causality. As I linked elsewhere, Sean Carroll has a solo podcast episode[0] where he talks about a few methods by which time travel could be imagined to be possible, given our understanding of the limitations. As is the case with the drive you mentioned, it's often the case that it's something like "well, if we imagine some special case that we don't think is forbidden, we can do xyz". I imagine at some point a few of these not-technically-forbidden holes will be blocked, but also it's not a certainty that all that is true can be shown to be so.
Your link really doesn't provide any basis for FTL travel.
No, I know it doesn't provide any basis for FTL travel. It was more a link for the commentors stating that nothing can travel faster than light. I should have labeled it better =/
Well, it doesn't really show something travelling faster than light, any more than if you shot a laser at the moon and looked at the speed of the dot on the surface as you moved it through some angle. The dot can move arbitrarily fast, but nothing in the system is actually moving faster than light.
What is impossible for reasons related to space and time and light is going faster than light in the typical ways. It does not mean going faster than light is universally impossible, just those ways.
