We have been visited by extraterrestrial beings

He first describes the incident known as the "Battle of Los Angeles". While it is quite the curious incident and it's easy to jump on it as absolute proof of extraterrestrials, I think it really needs further examination. First off all I'd like to note that while his source does claim that the objects were supposedly moving at 200 mph, this can be nothing more than a wild guess. Not only was there no way for the actual speed of the objects to be measured, but even if a person was looking at the objects it would be very unreasonable to trust their evaluation of the speed of the object due to the panic as well as distance between an observer on the ground the the flying objects. In 1983, the Officer of Air Force History concluded that the most likely explanation of this incident was as simple as meteorological balloons causing panic and setting off the event. This also explains my opponent's second point (about no wreckage being found) as balloons are capable of taking damage from anti-air rounds without necessarily being destroyed as a plane or rigid flying object would be. . http://www.ibiblio.org... Overall there seems to be a lack of legitimate evidence that shows these objects to be anything of non-Earthly origin. If my opponent could provide evidence that these objects were indeed UFOs or something of the sort, then it would be worth discussing. My opponent's entire second point is essentially that we can see certain very advanced aspects being shared among civilizations and this should be attributed to assistance from extraterrestrials. First of all, virtually ancient civilization can be seen to have built some amazing things that seem "ahead of their time", so is my opponent suggesting that every civilization was visited by aliens? On a side note, it doesn't make sense to me personally that aliens would come to Earth to. .. show people how to carefully place rocks? In the example of Puma Punku that my opponent brings up, why didn't the aliens perhaps show them "the wheel" instead, which seems much more useful? The "sharing of knowledge" that my opponent describes seems to be strangely specific, and nearly useless to humans. Even though my opponent has only provided one example, I agree that there are remarkable similarities between ancient civilizations. However, I feel like these similarities can be explained by "Earthly" means. I mean, we're all people after all, so if presented with the same challenge and similar resources, it seems pretty logical that people would come up with similar solutions. All my opponent has really done in his second point is state that ancient civilizations had some interesting similarities. He then provides extraterrestrial interference as a solution. Where is the connection though? My opponent has done very little (if anything) to show why it is extraterrestrial visit that is the answer to this question. ". .. if aliens were to come here what else do you think they would do? Most likely exactly what we would do, share and exchange knowledge. " I actually disagree here. If we look at human history we see that pretty much any time a more advanced civilization come across a less advanced one, there isn't much "sharing of knowledge" as much as conquering. Why give knowledge to the lesser civilization when they can be conquered, enslaved and robbed of resources? This is exactly what we see pretty much any time in human history (such as when Europeans came across Native Americans). I curiously await my opponent's response.