1. Yes, it would require laws of multi-dimensional physics that haven't been discovered. I'll address your #3 first, then #2. 3. For interstellar travel in what we normally regard as the 4-dimensional universe, you're right. The speed of light would be the barrier preventing us from ever accomplishing interstellar travel. But we don't live in a universe limited to 4-dimensions. We live in a universe of multiple dimensions--far more than 4--possibly infinite dimensions, and they are all interconnected in ways we have no hint of really understanding at present. 2. The only way we can achieve interstellar travel would be by circumventing the speed of light barrier. What would be required, and what ETs currently use, is a form of inter-dimensional travel that takes you from our 4-dimensional universe into a parallel reality, thru which you eliminate the vast distances separating you from your destination points before you re-emerge into 4-dimensional space again. Since in our universe space & time are connected (Einstein ), while in that parallel universe eliminating distance (space), you'd also be eliminating time, which is connected to space. Travel time would be shortened to almost nothing along with distance. Trans-dimensional travel allows interstellar travel to be possible. As my former post #3 suggests, I believe it's already being used by ETs to come here, and will someday be used by us as well.
I think the most glaring example of continuing, redundant, reoccurring proof are the annual appearance of multiple crop circles around the world, and especially in England. I know people try to make them occasionally, but the crop circles made by humans and those that appear out of nowhere, generally at night, are very different animals. The ones made by humans damage the crop and leave footprints all around. The ones made by ETs don't damage the individual crop strands, never leave evidence of footprints or mechanical device tracks, and result in the crops within the circle growing faster & healthier than the crops located outside the circle. Also, after harvesting, crops continue growing better & healthier for several years. That's not true for those made by humans. There are some good documentaries that detail these differences on YouTube, as well as several books detailing the strangeness connected with the ET crop circles--strangeness that cannot be explained by human actions. I recommend you evaluate some of that evidence for yourself.
We have no way to predict what intelligent E.T.s would be like. We're stuck with ourselves as the only example of intelligence, such as it is. It does not seem probable, however, that a form of life intelligent enough to ferry itself all the way here would be violent. If they want resources, they could obtain them from other places and avoid conflict with things such as us. I also expect that our kind would only ever travel to another world in peace, not to wage war. Our colonizing ancestors did not have to cooperate and develop anywhere near the sort of sophisticated technology to get around the world that we or our descendants would have to develop in order to reach another star system, so I think it's very unlikely that any life form accomplishing this would be so primitive in its thinking as to go wage war on an alien species. There would need to be a substantial perceived threat to them from that species first. Might we start a conflict with aliens if we attacked them upon arrival here? Probably not, seeing as how we can't very well pursue them to their home world and they would have to understand the risks of visiting another populated world anyway.
There is no credible evidence that we have encountered them. Let's suggest that we have been visited by aliens from Proxima Centauri, the nearest star to our own which was formed at around the same time as the Sun. With current technology, the trip would require about 30,000 years. There are no rest stops along the way. You are operating and opinion and belief, not science and provable knowledge.
Science is not always provable and you're referring to our current technology, not theirs. There may exist space warps. Why would they need rest stops? There's plenty of evidence, but evidence is subjective. For a non-believer why are you spending so much time in this discussion?
True that science is not always provable, however, if your theory is not able to be disproved, then it is not science, it is merely conjecture.
"Credible" is a loaded word. As soon as you see evidence you don't like, you can just claim it isn't credible. In fact this is a common response from debunkers - No matter what evidence you present, it can't be true so it isn't. There is a great deal of credible evidence. There is no public "proof" or scientific evidence. For example, the testimony from high-ranking military and intelligence personnel clearly qualifies as evidence [in any court of law]. When a belief or view is based on observations, it isn't a theory. If my best friend sees an alien, tells me about it, and I believe him based on our long friendship, I'm not promoting a theory by choosing to believe him. The only conjecture would be that because Bob has never lied before, I extrapolate that he isn't lying now.
In the real "Fire in the Sky" event, with Travis Walton, five men were under investigation for murder and passed a lie-detector test administered by the State's expert. They claimed they saw Walton taken by a UFO they had encountered in the forest, while returning from a day of logging operations. The man who administered the test concluded that they were being truthful when they said they saw Walton hit by a beam of light, knocked backwards through the air and into unconsciousness, [they feared he was dead] and taken by a UFO. Walton confirmed their story when he was "returned" a number of days later. This was a murder investigation. It doesn't get more serious than that.
A few examples, Gordon Cooper - one of those who went to the moon - publicly stated that when he was in charge of test flights, a UFO landed at Edwards AFB, in California. He saw the clear film made when crews approached the craft with cameras running. When they got too close, the craft took off. Capt Jacobs, in charge of photography, and his commanding officer Major Mansmann, publicly stated that they saw film obtained by Jacobs, of a missile test near Big Sur, Ca. Some classic disk-shaped object could clearly be seen entering the frame, running circles around the missile, and then hitting it with a beam of light several times, apparently causing the missile to fail and tumble back to earth. Col Halt, and his subordinate officers from the time, have publicly discussed an inexplicable series of events, including a UFO landing in Rendlesham Forest, next to Woodbridge AFB, in England. The security officer from the time claims to have touched the triangular craft while it was landed on the forest floor.
Maybe they don't have a hierarchical society. Is it likely that we have been visited? Suffice it to say that disparate cultures from around the world have legends describing beings that come down from the sky. But statistically... Either warp drive or the like, or transdimensional travel is possible, or it's not. We can't know. There are no identifiable odds. It is possible or its not. We just don't know. Either highly advanced beings inhabit the universe and explore the cosmos, or they don't. We can't know. It could be that warp drive et al. is common to advanced races and visitations are a near certainty. Or, the chance of an encounter could be zero; or anywhere in between. What are the chances that we have been visited in the past? It ranges from a near certainty to zero. They may have been around for thousands of years, in which case there is nothing to worry about.
I think that is right, can't know. Man knows very little. That's what they will say about the 1st century of the millennium in the 2nd, should earth continue to be inhabited by mankind.
It must be falsifiable. So it must make a prediction that must be true if the theory is correct. If it fails, it has been falsified. If it passes, it stands as evidence that the theory or hypothesis is correct; not proof but evidence. You can never prove a theory is true. Theories can only be proven false.
A problem with the extraterrestrial hypothesis - the assertion that some UFOs are from some highly advanced, non-human race - is this: Almost no evidence will suffice. The reason is that people tend to weight the required evidence according to the weight of the claim. Said another way, extraordinary claims require extraordinary evidence. In other words, the standard for evidence is admittedly subjective. I was talking with a friend once, who was an avid non-believer in ET visitations. His world view ended with Einstein and the fixed speed limit of C. So I became interested in what evidence for an ET visitation he would accept. "None!" he retorted. WHAT? I thought he was more logical than that. Surely there must be something that would prove beyond a doubt that ETs are here. So I listed a number of options for evidence, such as DNA, non-earthly alloys... that sort of thing. But he insisted that any of those things can be faked. Okay, that's a stretch, but there must be something. Ah! Then the obvious hit me. "Okay, what if an ET landed its UFO in your backyard. A non-human being emerges and finally takes you for a ride in his flying saucer. You would have to accept that so there is clearly some standard for evidence. "NOPE!", he replied. "I would assume that I was hallucinating." He thought he was being logical. But that is illogical. He had limited his logic to the point that no evidence for anything was possible... unless he wanted it to be true.
