Valrifell wrote:San Lumen wrote: an alien race could know far more about physics then we do. Why do you keep assuming that our current understanding of physics is all there is to know?
Again, our fundamental models of physics are unlikely to be wrong, but incomplete. This is a very fundamental difference. There is nothing that Einstein has predicted that turned out to be false or unobserved, so it's likely he is correct, but that doesn't mean physics is "solved". At the breaking point of models, new physics exists, but new physics doesn't replace old physics, it builds on top of it.
It's unlikely that you can accelerate something FTL without infinite energy, I say with 99.99% certainty.
Only because we haven't figured out how.
And perhaps an alien race has figured it out and our assumptions and models are wrong and their ships can't be seen by our technology. Some UFO sightings involve maneuvers and technology that is simply impossible for any current level of tech we have.