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    23 Alien UFO Theories That Are Terrifying Because They're Impossible To Disprove

    “They leave us alone out of fear that we’ll destroy ourselves if war accidentally breaks out.”

    This week, Reddit user u/Sisyphuzz asked, "What’s the best theory on UFOs or aliens you’ve ever heard?"

    The thread quickly took off and received over 10,000 responses (and counting). The theories range from mind-blowing to terrifying to utterly ridiculous — but every one of them is worth reading. Here are 23 of the best...

    Oh, and one more quick note: The term "grays" or "gray aliens" refers to the stereotypical, clichéd depiction of aliens that have become their most iconic and well-known representation — sort of like this (or some variation of it):

    An alien with a very thin body a large head and big eyes

    1. "Aliens are long gone."

    "The odds that humans will cross paths with another intelligent life form are slim. What if the aliens we are looking for are an extinct race of beings that existed millions of years ago? Maybe their civilization peaked during the age of the dinosaurs or even earlier. Who knows? They may have visited Earth when the most complex life was a single-cell organism and just moved on."


    2. "There is no one else out there."

    "We are those advanced aliens. The universe is still in its infancy and we are the first intelligent beings."


    3. "We are the first and/or the most advanced life forms at this moment in space/time."

    "I don’t remember where I heard it (maybe some NPR program) but it’s interesting to consider. We often discount the idea that we could ever be that special, but there is always the chance that we are. Someone had to be the first; that someone might just be us."


    4. "All the UFO sightings throughout history are just humans from the future on a time-traveling safari meant to observe how we were in the past."

    "They are supposed to keep out of sight; but thanks to human/mechanical errors, there have been hiccups with their cloaking that have resulted in being seen. That's why there have always been so many reports of them throughout history, but there has never been an attack. It's just us. Also the reason why we don't see as many examples of UFOs now even through pretty much everyone has a camera is because people are not that interested in this time period since we already document aspects of human life all the time."


    5. "Roswell, New Mexico, is pretty convincing."

    "The fact that a military expert identified it as a spaceship publicly and then had to do a very staged photo op to walk back his claims, and that a bunch of people in the military had weird stories from that time like flying a general to New Mexico and then straight to Washington, suggests they might have found something. Also, the fact that the government had to change their story and admit to lying doesn't sound great."


    6. "They're protecting us from ourselves! ✌️👽✌️"

    "The first nuclear weapons test was on July 16, 1945 at the Alamogordo Bombing Range in New Mexico. The Roswell UFO Incident was on July 7, 1947, in Carrizozo, New Mexico. The distance between these two locations is 132 kilometers. They detected our use of fission and were coming to warn us of the dangers. Since then, most UFO sightings are at nuclear test facilities, and eyewitness military personnel have reported they have shut down nuclear warheads mid-flight."


    7. "They leave us alone out of fear that we'll destroy ourselves if war accidentally breaks out."

    "We split the atom but made weapons out of it instead of trying to reach the stars."


    8. "Any species advanced enough to find us wouldn't make contact."

    "They'd study us the way we study animals. Ideally, with minimal interference. Compare the average 'abduction' story to the way we dart large animals, collect data, and leave them to wake a bit groggy and confused but unharmed."


    9. "There are so many star systems with potentially inhabitable planets out there that the chances that we have been the only life in the universe is extremely slim."

    "The question, instead, is whether life arising elsewhere has managed to survive destruction and remain alive today such that they might be able to contact us. That is to say, there have probably been countless civilizations for the past several billion years that simply haven't made it."


    10. "That if any civilization elsewhere in the universe had the technology to reach us, for any reason, they'd also very likely be able to disguise their presence from our detection methods."


    11. "Life in the universe could be so unrecognizable to us that we wouldn’t even register it as being alien life.

    "What if life on another world was not carbon-based, but another element? How would we even know what to look for since our definitions and descriptions of life are based on a completely different perspective?"


    12. "Nobody's been here and probably nobody ever will."

    "Let's say the closest alien civilization, 92 light-years away, died out hundreds of millions of years ago. The next closest, 460 light-years from us, will begin evolving any day now and will attain technical mastery rivaling ours in about a billion more years. Currently, there are two other civilizations in our galaxy: one waning and one waxing. The closest of them is 23,737 light-years away. We don't just have to line up on a relatively close spatial scale. Time frame is as much a factor as distance."


    13. "We haven't been visited by UFOs or aliens."

    "The movie Contact actually makes a good case for this. Our most powerful broadcasts have traveled, at best, a few dozen light-years from this planet. To put that into perspective, if the Milky Way galaxy were the same size as North America, the Earth would be a speck of dust floating around a living room in a house in Arizona. Our most powerful broadcast signals have made it to the end of the driveway or at best across the street. If there were a hyperintelligent species two blocks over desperately listening for signs of intelligence in the neighborhood, they wouldn't even know we existed for at least a couple thousand years. When they finally picked up our signal (our first television broadcasts), it would take their response another couple thousand years to arrive here."


    14. "If you wanted to explore space, you'd send technology instead of risking a life."

    "The little gray/green men — also known as 'grays' — and other clichéd depictions are just biological computers that they can control and that's why they look so simplistic and unidentifiable."


    15. "That 'grays' aren't fully biological but rather remotely controlled androids."

    "Or that they are biological, but their 'gray' appearance is a suit and not the actual body. Imagine other life-forms looking at our astronauts saying, 'Here come the marshmallow cyclops creatures again.'"


    16. "There are no aliens and no abductions ever took place."

    "There is a very simple explanation as to why abductees independently described 'gray aliens' as looking the same. They are abstracting residual memories left over from being infants and looking up at adults. Before an infant's visual cortex is fully developed, an adult human looking down at them would appear rounded and gray in color with large eyes. Cross that indistinct memory with a sleep state subconscious and standard psychological patterns, and boom: alien abduction. It also explains the sensation of being lifted, examined, and probed."


    17. "Aliens may perceive the passage of time differently than us."

    "Our whole existence could play out before they've had their proverbial morning coffee or vice versa."


    18. "Any civilization advanced enough to get anywhere close to interstellar travel becomes too energy-intensive and destroys itself before it gets far enough for interstellar contact."


    19. "We don't allow ourselves to contact lost tribes in the Amazon or other remote places. Extraterrestrials may have similar laws on a galactic scale."


    20. "We are the aliens that we’re looking for."

    "Mammals are not native to earth. The asteroid was a massive chunk of our former planet and we populated the earth after that."


    21. "UFOs are higher-dimensional objects moving through our dimension."

    "Like, if we moved a 3D object through 2D space, it would look crazy weird to a 2D being. A hollow sphere would start as a dot, then look like a Hula-Hoop that starts small, gets big, then gets small again. They'd have no idea what they were looking at. So, WTF would a higher-dimensional object look like passing through our 3D dimension? It might rapidly change shape or appear to move at incredible speed as it moved through our space-time. Gravity wouldn't affect it (I don't think). It wouldn't appear to have any form of propulsion."


    22. "The US military has orchestrated alien sightings and kidnappings, as well as funded UFO religions and conspiracy theories, to prevent people from being taken seriously should they happen to notice some experimental planes and so forth."

    "There are no aliens, but there are US military agents in goofy spacesuits who mutilate cattle and 'probe' deranged people to encourage them to make fools of themselves."


    And finally,

    23. "They came, they saw, they weren't impressed."


    You can read the full thread of responses on Reddit.

    Note: Some responses have been edited for length and/or clarity.