As a very qualified researcher, I have been working to disprove the Flat Earth Theory, but I have found out so much more than I thought...
History of the Hollow Earth
The idea of a hollowed Earth has appeared in mythology and folklore since the dawn of humanity, becoming the realm of the Greek Underworld, Christian Hell, Nordic Svartalfar, among others. There is even a mention of a subterranean city called Shamballa in one Buddhist story.
Depending which mythology you read, there are multiple cavern systems in the world that will connect to the universal concept of the underworld. Often times, these caverns form the mystic gateways that allow demons, spirits and other such creatures to escape into our world.
The idea of the hollow earth was first put forth into potential science by Edmond Halley in 1692. Imagine the earth looking somewhat like the inner rings of a tree. Each of the lines that are formed would be the inner layers of the earth, each having their own atmosphere, life and landmasses. Each of these inner spheres of the Earth, each a mini-planet in and of itself, would rotate at its own rate, on its own axis, which causes the anomalies with compasses in certain points of the world.
Other ideas for the interior removed the idea of multiple layers for one layer with an sun at the core of the Earth, providing light for the subterranean world, or even two twin suns in the interior.
Despite the hypothesis of an underground realm of potential for life, there has been a large amount of scientific data to prove that the Earth has a mantle, outer core and inner core. But does that really disprove anything? We haven't ever actually drilled all the way to any of these other layers, we haven't even broken out of our crust.
The concept of the hollowed planet has been used in pop culture in books and films such as Journey to the Center of the Earth, Dante's Inferno and Ice Age: Dawn of the Dinosaurs, which leads me to beg the question, why is it too outrageous to think that it's impossible to have another layer of the Earth?
Flat Earth vs Hollow Earth
Recently the idea of the Flat Earth has come up into popular culture, for reasons that I don't fully understand. The Flat Earthers (as the name implies) believe that the earth is flat, much like the world from Terry Pratchet's Discworld. Now, the Flat Earthers probably don't believe that the flat Earth is on the back of a quartet of elephants on the back of a giant turtle floating through space (or do you? I don't want to be ignorant), but they do strongly believe in the flat Earth. Now, there has been significant proof against the flat earth for centuries (thank you, Christopher Columbus), but for some reason, it has gotten a cult following once again.
While I don't know for certain that the Earth is round (although I'm inclined to believe it is), I do have to wonder why there isn't a more vocal group of Hollow Earthers. As I mentioned above, there really isn't any way for us to prove that there isn't something between the Earth's crust and the mantle. Who is to say?
The (Formerly) Flat (Now) Hollow Earth
Here's where I stand. I think that it's very possible that the Earth was at one point flat. In fact, I would put money down on this. We really have no way of knowing. For all we know, there was a point where the planet was actually banana-shaped. The only thing we can (tentatively) say for certain is that there was only one supercontinent. But what if Pangaea was only one side of the planet? I know what you're thinking, "Man, this guy has no idea what he's talking about," but hear me out, alright?
What if, over 65 million years ago, our little blue ball was actually a pancake in space, rotating like a plate in the microwave. It would stand to reason, then, that there are two sides to this cosmic coin, right? On one side of this, we know that we've got Pangaea, and we also know that dinosaurs were here, right? But what if these weren't exclusive to one side? We know that Pangaea became the continents that we know today, but what if they aren't the continents that the dinosaurs walked on. The age of reptiles and the age of mammals happened simultaneously, just on different sides of the planet, separated by a few dozen miles of the crust.
But wait, you said that the Earth used to be flat. How do you explain it getting round? I'm glad I asked. We "know" that near the end of the age of dinosaurs, a meteor, roughly six miles long smashed into the Earth, wiping out all life as they knew it. But, what if somebody doesn't want us to know that the meteor that hit the Earth was actually much bigger? Say, 700 miles in diameter (give or take). The force that this meteor hit the Earth with would have been enough to actually wrap the crust around the meteor. The dinosaurs were nearly all wiped out, save for those that found safe haven in the oceans. The mammals were now on the exterior of the planet, leaving a thin layer of the interior of the planet hollowed out, potentially now supporting life in the interior. So, the flat earth has now moved onto the round and hollow phase of it's life.
But What About Fossils?
Dinosaur bones have been found all over the planet. This is true. So, how do I explain that if the dinosaurs were on the opposite side of a flattened Earth? Easy. If you hit something with 7.2198 x 10^25 Newtons of force, you're gonna probably push some things through that few dozen miles of crust. Now where did I get that HUGE number from? The Earth's core's (which is, for the sake of this article, the meteor that hit the Earth) mass is 1.719 x10^24 kg. The fastest meteor was clocked at 70 m/s, and the slowest was clocked at 14 m/s, taking the average of 42 m/s and applying it to the force = mass x acceleration equation, we get that big number above.
The proof is...doubtful at best, but I think it deserves a much more in depth look, rather than just accepting the either flat or round earth theory.
Look, I'm no scientist, but I think it deserves to be looked into by people much more qualified than I am to see about this secret layer that the dinosaurs may be in.
Thanks for reading!