The history of the world serves to provide sufficient common understanding of science and technology that we may now answer and understand the ultimate question of life, the universe and everything.
From the perspective of physics, Newton's laws work on a human scale. At an intuitive level, these feel right.
Einstein's general relativity works on the large scale. After a bit of explanation, it's straight-forward enough yet too conceptual for everyday use.
They are but two of the proverbial blind men touching the elephant.
Rather than attempting to comprehend the workings of the universe, there might be easier path: reverse-engineering reality.
Attempting to comprehend life by examining the brain, mind, culture or soul mistakes the equipment as the end rather than a means to an end. Transportation makes more sense after understanding that the car merely provides access to adventure and a destination rather than being an expression of motion.
Forget about doors of perception. The rabbit hole you found is only a dead end. And there really is a spoon, Neo.
Our real just happens to be someone else's virtual, someone in another context-- using "virtual" as the postmodern replacement for ethereal, abstract or not quite tangible.
Without speaking as metaphor, how might the world operate if running on a computer? What would be needed for a large-scale system? To adequately handle demand of usage, what artifacts would be present due to side-effects of being hosted on multiple servers?
Einstein can be explained away by the grouping mechanism required for multiple entities to negotiate a common slice of spacetime, of reality. For entities existing outside of this shared slice, the relationships that broke Newton are essentially due to side-effects of those external to that particular segment.
Likewise, Newton works nicely within certain scales of economy due to tightly coupled communications among all entities within a shared reality.
Reality, realities, slices and spacetime are all the same. That is, we're dealing with the possibility of multiple mutually contradictory realities that also offer the probability of a single common shared reality.
It boils down to capacity of the server you happen to reside on.
But speaking of boiling-- if you haven't leaped already, my little frog, hang in there just a little longer, if you would.
You see, life is merely technology. It's a wet technology, not the dry stuff of silicon computers or even polymer chains to produce the plastic box that makes it look pretty. It's wet, as in the muck that gets stuck in the tread of your shoe after walking through a field of manure.
As Oscar Wilde decreed, "life is too important to be taken seriously." It's just a game, fool. Get over that fact, and get on with it already.
This game, however, is constantly changing.
Consider a game you played as a child, such as tic-tac-toe. Why don't you play it any more?--it's too easy to win if you're playing against a child or always a stalemate when playing versus another adult. You've moved on to more challenging puzzles-- perhaps the the New York Times' Sunday crossword, a thousand piece jigsaw puzzle or poker. Why? These are more fulfilling to you now.
So too the universe has matured.
Back when the world was flat, reality was less complicated. No one had yet invented gravity, the seafloor or a jumbo-hybrid home owner's mortgage.
Earth had not yet needed to be round or even be part of a solar system. Lessons to be learned during those lifetimes still involved survival and power but on a much simplified scale.
At that time, survival was with respect to basic "needs" like food, shelter and clothing without complexities of legal definitions for organic food, fears of asbestos mixed with black stachybotrys mold and clothing made in sweatshops with doors chained.
Instead, the game involved, "Let's get Mikey... Hey, Mikey...! Look, he likes it... and hasn't died yet, so it must be okay to eat... but let's wait another couple of days before trying it ourselves, just to make sure."
Fast forward through the ages: challenges advanced to new topics, populations grew, and the servers on which the world was running had difficulty handling the load.
Atlantis didn't sink; its server crashed. And it crashed hard! Surely, someone was fired over that one since they couldn't even restore it from back-ups.
The continents were separated because each server cluster had to run independently. There were just too many players for it to all be hosted within a single server farm. And so, the "cradles of civilization" came to be.
Eventually, there were improvements in interoperability, and more than just the occasional Viking ship could cross an ocean. But before then, sea monsters were deployed to keep people from finding the edge of the world-- or keep them from telling others what they saw!
Keep in mind, however, that mention of "servers" and "clusters" here are metaphor based upon our reality and not implemented using Intel processors (and definitely without products from Redmond, Washington).
Again, it's a wet technology without circuits or gears. Chemistry and physics are side-effects of implementation-- shadows that flicker on the walls of our perception.
For the reversed-engineered reality, yes, it will run on open-source operating systems and probably be marketed as a massively multiplayer on-line game (MMOG).
Start your own world, and let the games begin.