"We don't know, therefore my preferred theory is true" is just the argument from ignorance fallacy. Plus, of course, "UFO" is a badly-defined term: It either m

"We don't know, therefore my preferred theory is true" is just the argument from ignorance fallacy. Plus, of course, "UFO" is a badly-defined term: It either means an unidentified flying object, or it means a spacecraft piloted by extraterrestrial beings, and that poisons the whole discussion around them. There's nothing you can talk about in regards to UFOs as long as people refuse to agree to a single basic definition.