People and objects vanish all the time. Some resurface while others are never seen again putting this in the category of exotic physics.
Unexplained disappearances occur at sea, in the air (planes) and on land. This takes us to portals and vortices that open and ... just like that ... close after someone disappears into them.
Such occurrences were often part of the alien abduction experience during the years humans were taken and experimented on.
Disappearances often involve 'missing time' meaning the person experiences time differently at the point of destination than in our part of the simulation.
Sometimes - when the person reappears - it's in an area that has been searched over and over again. It's like being an archaeologist and making a major discovery in an area that has been excavated many times - then suddenly something is found that is part of a known or unknown ancient civilization.
People often question the disappearance of ancient civilizations assuming it had to do with an ancient pandemic, climate change and/or natural disasters forcing people to assimilate into other cultures. Yet the feeling is there is something more ... something unexplained. It could be as simple as
Black holes take us to Simulation Theory where realities of experience are created. They may also explain some disappearances.
There is a theory that tiny black holes open and close randomly not just in space but on the planet though we are not programmed to see them unless created in a lab where physicists seek to harness their power and thus travel through space and time (the grids).
But what would they find?
Most of what we see in outer space is green screen because reality is projected illusion easily altered based on the algorithm of its design.
More often than not when a civilization disappears - an insert in the simulation has been edited then deleted in our computer generated reality.
Disappearances also occur when there is a glitch in the computer grids or the simulation reboots.
At the end of Time (Illusion) our reality Fades to Black and everything vanishes.
Bermuda Triangle and Similar Areas