Let em explain to you what these things are, probably over several posts. This issue I have is that I have studied the most relevant sightings and encounters for 10 years. Most who I discuss this topic with are very ignorant of the subject, relying on "speed of light" arguments they vaguely remember from their HS physics teacher. There is also a great deal of noise in this signal-to-noise ratio (long since debunked cases and assorted hoaxes), which must be filtered, and most don't bother to do. There are many, many "obvious" cases of encounters of UFOs, though they do constitute a small percentage of possibly UFO encounters.
The "smoking gun" UFO case is without question the declassified 2004 Nimitz case that came to light last December. Lt Commander Fravor, the pilot of the fighter jet has gone on media, bravely, many times to state what he video'd and tracked was under intelligent control and not of terrestrial origin. I will not go into the details of this case, but this "Tic Tak"-shaped UFO was observed sporadically for several weeks by the crew of the Nimitz in '04. When the Princeton was nearby doing training maneuvers, and the UFO was spotted again, two fighters were dispatched from the Princeton to investigate, one piloted by Lt Cmdr Fraver. The pilot of the other figthter corroboates Fraver's account, but has been less accessible to the media. Fraver has been outspoken -- seemingly to warn us they're here -- and they most definitely are, have been. This is a recent incident with video, radar, and multiple high credibility witnesses. It happened. And it was released from the vaults of an above top secret Pentagon program to study the phenomenon, a story the New York Times broke last December. The director of that program, Luis Elizando, stated on the record in several televised interviews, "My personal belief is that there is very compelling evidence that we may not be alone". Incidentally, this is the biggest story in human history. The mass denial (not "hysteria" -- mass "denial") of it is a fascinating trait of human psychology.
They absolutely exist and are monitoring earth. Likely, they monitor all pre-singularity break-away species like man. These species are likely machine "life" and the "UFOs" are not vehicles with "little green men" but the "aliens" themselves. Some thinkers on this topic argue that
most intelligent life in the universe is not biological, but has long since shed its frail and short-lived biological substrate and that "biological man" is merely a transitional species. When "we" achieve the technological singularity ("singularity" being a point past which we can not conceive...) through the advent of "recursively self-improving, self-programming conscious general artificial intelligence", this new life form we spawn will either co-exist with us, destroy us (the "hard take-off" scenario), or we ourselves will somehow merge with it. This follows an evolutionary pattern all intelligent species undergo. Our "ape brains" have limits to what we can explain, predict, and control of the matter, energy, and forces in the universe. It can take us so far as a rudimentary understanding of physics, the ability to split the atom, and the ability to create computers. Then, the computers take over.
We are on the cusp of recursively improving self-programming computers -- 25, 50, 100 years away -- a blink of an eye on a historical timescale. These "UFOs" are likely post-technological "Singularity" machine life, and the most commonplace (super) intelligent lifeforms in the universe. We are in our biological "pre-singularity" transitional phase but on our way there now with rapid advances in "narrow AI" (self-driving cars, AlphaGo!) with huge research dollars and resources devoted towards developing "general AI". If one believes -- and there is solid logical basis for such beliefs, that such beings constitute the majority of intelligent life in te universe, then these naively so-called "UFOs" are very common throughout the galaxy and may (because they're immortal or nearly immortal) outnumber biological life by orders of magnitude, having achieved Singularity (and subsequently immortality) long ago in their evolution.
How do they get here? Your HS physics instructor had no clue. Our best physcists have no clue. Why? Such problems transcend the limits our our puny meat-based ape-brains. But such problems do not exceed the limits (if there even is a limit) of conscious, intelligent machine life (the "aliens") or possibly even our very own next generation AI capabilities:
The most complex problem in physics could be solved by machines with brains
https://qz.com/897033/applying-mach...-the-way-to-build-the-first-quantum-computer/