If we live in a simulated world, doesn't there have to be a first world that's real?

Question

There are people who believe we live in a world, simulated on a computer. That computer must have been built in either another computer-generated world or a real world (by which I mean a non-simulated world). If it has been made in another computer-simulated world then the (simulated) computer on which the simulation (program) for "the next" simulated world is run must be a subset (by which I circumvent the notion of size) of the "previous" computer, which means that the computers on which the next-world simulations are run will be ever-decreasing subsets of the previous computer.
Doesn't this mean that there has to be a first real world because if the "stack of turtles" would be infinite there would be no limit to the increasing subset connected to a computer in a previous simulated Universe, sending the subset to infinity, when the simulated Universe gets more and more down the stack of turtles?
If the simulated Universe grows to an infinite subset (when tracing back the track of subsequent simulations or going down the stack of turtles) of the previous computer, whatever the programmers program into it, wouldn't it take an infinite time to program this infinite set, so the next simulated Universe never gets finished (and neither the preceding simulation) and the process stops. In this case, there has to be a first, infinite real-world (because such a world can't be programmed in an infinite computer). Programmers in this real infinite world can make a finite-world simulation.
This is a crude (but essential) outline of my thoughts on this subject, of which I clearly think that a real world has to be there.

By the way, I think it's a waste of time to elaborate on the idea that we live in a simulated world (which indeed, as written below only shifts the problem of explaining Nature to an alleged previous simulated world, etc.). I'm satisfied with the world I live in and it's my gut feeling that the world I live in is real. So in my eyes, there isn't a first world that's real but it's the world we live in that's real (I think it's a creepy thought that we live in a simulated world, just I think it's a creepy thought that we're made by (a) god(s) or by evolution for that matter). But despite all that, I'm still curious how others on this site think about this subject.

Answer 1

We can not carry the argument past the first step because if our physical laws are simulated then we know nothing about the "physics" of the world that does the simulating. In particular, it may make no sense to say that one computer is "bigger" than another if they function by completely different principles, space or time as we know them may not apply to our simulator either. For that matter, the chain of simulations if it comes to that, doesn't have to be finite, there might be a simulator that simulates an infinite chain of other simulators each one simulating the next, and on and on.

But before we get into turtles all the way down let me point out that your question exposes the main weakness of "universe as a simulation" proposals, they lack explanatory value. The simulation idea is supposed to explain how our universe functions, but all it does is shift all the questions to the simulator: what kind of reality does it reside in, what kind of physics does it obey, what kind of intelligence is behind it? We do not need to deal with the infinite regress here, the first step is already superfluous. This is like the homunculus theory of how the mind works, there is a little man in the head that does the thinking, it does nothing to explain how the thinking is done. We might as well cut out the little man, and simulations.

This said, there is a school of thought that argues that one can have a "simulation" without a simulator, pixelated world which is already "real", not run by another one. This is usually phrased differently, e.g. Lloyd's universe as a quantum computer, or Tegmark's universe as a mathematical structure. However, something always seems to be missing in such accounts, namely how such a "simulation" manages to implement itself while lacking physical powers (in the ordinary sense), I even asked a question about it: How can the physical world be an abstract mathematical structure? But it seems that explanations provided always appeal to some sort of implicit physical implementer, i.e. the underlying "real" world, or simply God. The root problem is that we do not know how to leap either from mathematics to physics, i.e. from inert idealities to physical action, nor from physics to psychology, i.e. from physical action to perception and awareness. And without "simulating" those it is hard to see how self-simulation proposals can get off the ground.

Answer 2

Also... as far as the Simulation Argument, you have to ask "what difference would it make?". If we're simulated, what would be different from if we're real? How would it affect things?

If it would make no observable difference, then it's not a question science can answer. There is no answer, nobody could ever know.

Of course, some clever soul might think up some way of testing our simulation. Perhaps run a really odd process on a quantum computer. Reality gets odd on the teeny-weeny scale, maybe there's a trick there... [but probably not]

Do you remember that Dr Who episode where it turned out they were simulated? All random numbers turned out the same. Up until the weird glowy door appeared, they had no idea about the simulation.

Answer 3

Yes, there does. Even if we're simulated by some computer, in a world that itself is simulated in a bigger computer, somewhere along the line there has to be a computer that actually exists.

Of course the nature of that computer, and the world it exists in, we can say nothing about. We can say nothing about the world one "level" above ours either.

That said, the simulation argument has strong tendencies towards being unprovable (and worse, undisprovable). It's currently undisprovable and likely always will be. Until one of our gods throws his joypad across the room and breaks it, after another inconceivable intelligence calls his mum gay.

Answer 4

Thats a pretty big if... Assuming that eventually, stepping up through the simulations there is a real world containing the first simulation, you are asking "Does Inifinity have an upper bound?" That being the case, and we are living in a simulation, it means the universe does not go on forever in all directions, nor does it cycle back on itself in a loop. I painted a picture called Deus et Machina that deals with this; a machine stands at the edge of the universe bearing a flag, in front of him is God's face (I used classical Methuselah imagery to depict the Creator), rubbing His beard as he pondered on the creation of his creation. By proposing that our simulations could ever be complete enough to simulate us, we're ignoring a hard fact about complexity itself. While a simulation of the universe could be Turing Complete, it could never contain itself, being an information system. To store a unit of information requires two things, itself and something to represent it with...

This means that the universe, being made of atoms that are all identical and only describe it by arrangement, is itself a representation of something; the question is what?

IMO, the universe is simulating itself, meaning there are no levels to it, which resolves the information system paradox.

Take a leaf from a tree. It is made of atoms lined up in a certain configuration that define it as what it is. It is alive because it is swapping some of its atoms for others but retaining a basic but changing form.

Take a rock. It is made of atoms lined up in a certain configuration that define it as what it is. It is not alive because it is not swapping some of its atoms for others, and is retaining a basic and unchanging form.

In both cases, removing the atoms and replacing them with others does not affect the collection - it remains a leaf or a rock. Also in both cases, rearranging the atoms affects the collection, it is no longer a leaf or rock, it could be anything constructable from the units it is made of.

This demonstrates that the universe is only defined by arrangement, not atoms. It COULD be represented with anything that is unitary and indistinguishable from another unit - mathematics falls into this category, so theoretically mathematics could describe the universe but only if contained in a computer, an abacus, or a mind like a god - so it obvious that the arrangements we have are representing something. A leaf represents itself by being arranged like a leaf, or it would be something else.

This leads me to conclude that the universe is Cartesian in nature and thinks because it is, because the only other conclusion is that it was arranged by an external entity and is therefore proof of a Creator.

Answer 5

Turtles my dear boy, turtles.

This concern has been around since before the modern computer. René Descartes contested a similar concern in his Meditations, though for him the illusion was made by a mischievous demon. We have also seen portrayals of this in "The Matrix".

Unfortunately, the logical necessity for a Primary World cannot quite overcome the existence of an infinite regression. Much like aligning two mirrors towards each other, the image appears in an infinite regression. This is the plot of ##Spoiler Alert## "The Thirteenth Floor".

Another example that may put the concept into perspective is the old problem in cosmology posed by the "unmoved mover" paradox. As phased jokingly by Stephen Hawking:

A well-known scientist (some say it was Bertrand Russell) once gave a public lecture on astronomy. He described how the earth orbits around the sun and how the sun, in turn, orbits around the center of a vast collection of stars called our galaxy. At the end of the lecture, a little old lady at the back of the room got up and said: "What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise." The scientist gave a superior smile before replying, "What is the tortoise standing on?" "You're very clever, young man, very clever," said the old lady. "But it's turtles all the way down!" — Hawking, 1988

Answer 6

Simulation by definition means that it's a simulation of something. That 'something' should exist. So, if we assume there is a simulation, that by definition means there is a 'reality' which this simulation is a simulation (imitation) of. Even if there are many levels of simulations, there is the top-level 'actual' reality.

I cannot see why this is subject to an infinite regression. Top-level computer would have finite resources. Even if you are a simulation in a simulation (and so on) you are still bound by the actual 'real' hardware.