We have been visited by extraterrestrial beings

" The balloons would have also had to fly over mountains, and it is very unlikely (given the distance of where they would have came from) that this is possible." I'd appreciate it if my opponent provided a source for this claim, perhaps a link to a map. "If i could prove they are UFOs then we wouldn't be having this argument." Well yes of course haha, but I don't see at this point why UFO is a more plausible alternative to, for example, weather balloons. If you provide a source to back up your claim above, then this could be a step in the right direction for your argument. "But I can point you to a former Area 51 worker, who claims the US has worked on them before. " Alright, so you're now doing something to prove that it could've been a UFO, BUT this is strongly counter-acting your argument of trying to prove EXTRATERRESTRIAL origin. Your argument (and testimony) is evidence that even if it was a UFO or something of the sort, that it was still of Earthly, human origin. "No because not every civilization is ahead of their time. The expression "ahead of their time" means that the other civilizations at that time were far less advanced. So could other beings have taught the advanced civilizations? Maybe." Perhaps, but I still haven't seen why advancements are results of extraterrestrial interference in human affairs. "For example China for the longest time thought they were the only civilization on earth, so why do we find specific similarities between China and other civilizations that are so far apart. If alien visitors came, it is possible they spread some of the other ideas during this time. Ideas that these civilizations couldn't have acquired otherwise." But again, doesn't it seem more likely that humans being humans, came up with similar solutions to similar problems? "why are we reaching out and trying to find aliens today? Are we trying to find aliens to conqueror them? No, we want to share knowledge between the civilizations. So what if they are doing the same?" An interesting question, but I think we don't reach to share knowledge as much as to satisfy our human curiosity. Indeed, I don't think that the meeting of two civilizations (human and alien) would be a cooperative one. One would probably be weaker than the other, and would probably be exploited. So let's again sum up what we have. My opponent presented a source suggesting that the US has worked on something like UFOs. but doesn't this go against my opponent's point of extraterrestrial origin as we are seeing evidence that UFO-like machines are being made on Earth? On the subject of the similarities between human civilizations, I think we can only speculate on the interference of extraterrestrials, but let's this about it this way. 1) It seems more likely that similarities came about by Earthly means, such as those I described. 2) If extraterrestrials visited and somehow managed to communicate and help the humans (instead of conquering them, for example), why such specific technologies? Why not tell the humans how to treat diseases or maybe even give weapons to help conquer other civilizations or some more advanced tool than the technique of rock carving? If extraterrestrials were advanced enough to come here, I imagine they would have some very interesting things to share (which we don't really see happening). 3) Seems strange that they would visit us in the past, tell us how to carve rocks (I'm using this over and over again just because I don't have much else to work with, please don't mind it I understand there are other interesting things that past civilizations were capable of) and then never show us anything "cooler". 4) Don't know why they would want to help us in the first place considering that we are disgusting creatures. Anyways, thank you for the interesting argument and I look forward to seeing you on the debate battlefield once again!