Let's discuss the concept of interdimensional beings. Wikipedia has an overview: There is a hypothesis called “Interdimensional hypothesis,” relating that UFOs, aliens, shadow people, crop circles, Bigfoot, and ghostly activity are all explained by the passage of beings from another dimension occasionally crossing into our dimension and being glimpsed.
I’ll be honest. When I first heard about this theory, I laughed. It’s a normal reaction when hearing such a “universal” view of ghostly activity. Then, I started reading more about it and considering it. Honestly, the concept of souls of the departed lingering as if their lives on Earth weren't enough seemed equally as ludicrous.
Some things explained by this theory include the lack of evidence of visitations, the difficulty capturing them, their ability to show up and then disappear suddenly. The characteristic often associated with shadow people is that once they realize they’ve been seen, they dart off into oblivion as if they didn’t expect to be seen by people normally. There are also some areas like Bennington Triangle that have a wide variety of events occurring on one place that make them seem likely portals.
Let’s go back in time when a person would get a cut that became infected. They had no concept that tiny little microscopic bacteria were the reason they were getting sick and dying. The very mention of microbes would have made people giggle nervously. “There’s nothing there we don’t see with our eyes. That is ridiculous! Surely it is a matter of the person's character or perhaps their very soul.” Things that occurred were often explained by the supernatural or spiritual because if science didn't cover it, that's the category it was relegated to. Luckily, advancements made it possible to see things at a molecular level and realize that these very exceptionally tiny bacteria could create a chain reaction that would down a human. It was not the human's lack of moral fiber that created the illness but something spread easily by our environment and undetectable with our eyes.
The ghost world will some day face the same issue; is it supernatural or is it scientific?
We are in much the same situation now. We have all these different forms of phenomena, no way to truly capture them. I know this as an investigator that it’s an extremely frustrating thing when really the majority of the evidence if subjective personal experiences. Perhaps we aren’t able to visualize the means by which these phenomenon occur. And, perhaps they are not all separate issues, but held together by one commonality; interdimensional travel.
So, the next obvious question is; if they can travel into our dimension, why the hell don’t we drop into theirs? There are many explanations, some including technology and others assuming that perhaps their dimensions have exits and ours does not. There is also the possibility that, like a 2D photograph image can be in our space, we are in their space. The other dimension can perceive us, but we cannot perceive them because of the limitations of our human body and 5 senses. If a 2D photograph image had sentient thought, it would not know we exist because it cannot perceive width, only length and height. But, if we placed a finger on that photograph, it would see us for that moment we interacted. But, it would only see length and height, not the entire human attached to that interloper. It might be this way with the other dimensions - they can interact with us at will, but the only way we perceive them is when they interact with our dimension and we can only see that part of them we can perceive with a 3-dimensional reference. (see video below around the 17 minute mark)
Here is another consideration; what if when we are sitting at home, say, watching TV, we are being seen briefly by another dimension, but we do not see their dimension? Perhaps when we glimpse a ghost, we are briefly seeing something in another dimension which might also explain why it often times does not seem to see us or passes through walls as if they are not there.
Any way you look at the concept of interdimensional beings, I actually have it as one of the top of my list of explanations for phenomenon. I am more likely to believe that concept than souls being stuck here because they don’t know they’re dead or they have unfinished business. The fact is, once we shed this limiting 3-dimensional form, we could easily enter another dimension that gives us a whole set of new information we didn't have when we were "alive." This would be my concept of afterlife and it is supported by near-death experiencers who report colors that don't exist, and all knowledge, and the sense that when they came back, they believed that was the real world and this was fake. A depth of existence as vast or more vast than the 2-dimensional photo versus the 3-dimensional person represented in it.