2018. január 16., kedd

How to build simulated reality (and some thoughts about the simulation hypothesis)

Source (full article): https://medium.com/@thebojda/megaminds-abstract-evolution-and-the-consistency-machine-d2915a719443
Mind uploading and simulated reality are the holy grail of science and technology. Mind uploading is the key for eternal life and gives god like power in a new, “self made” (simulated) reality. If you are not familiar with mind uploading, you can find here a short introduction.
Mind uploading is the computer simulation of the human brain. According to the present state of the science, our brain is a network, built from inconceivably big amount of neurons, and our consciousness is the result of operation of these neurons. There is no any law of physics which prevent us to copy the operation of these neurons, and build a software which works totally identical way as our brain do. Sounds easy, but it is a huge technological challenge. Maybe the biggest (but last) challenge in the history of the human kind. As a technological challenge, it is only question of time when we will be able to solve it. Thanks to the exponential technologies like nanotechnology, brain scan, computer science, etc. it can be solved in a not too distant future.

If our consciousness is the operation of our neurons, the simulation would be totally identical to us. Not a copy of us, it would be us!


Mind uploading could be the key for the eternal life, for real interstellar space travel (we should send only our digital form) and simulated reality. I think, this will be the very last invention of the human kind, because if we can do it, there won’t be any more problems to solve. No more poverty, climate problem, overpopulation, wars, scarce resources, etc. because we will be able to build own realities where these problems do not exist. Let’s see how…
The very first idea of everyone is to simulate the reality particle by particle as we simulate the brain neuron by neuron. But I think it is wasteful and impracticable. Accurate simulation of some particles needs huge computing capacity (think the equations of the quantum mechanics), simulation of the whole world needs much more. So, simulation of every particle seems unsolvable. The good news is we don’t need to do this. Our brain is connected to the reality through a thin channel, the sensory system, and we have to simulate only the sensory stimuli. Just imagine an apple. For our brain, this apple is not a set of particles, but a set of stimuli (visual stimuli, touch stimuli, taste, smell, etc.). So, it is enough to simulate these stimuli instead of particle level simulation. It solves two problem. The generation of these stimuli needs much less computing capacity like particle level simulation, and things which are not observed by anyone are not needed to simulate. If we put the apple to a box, it is not needed to simulate any more, because we don’t see it, don’t taste it, etc. The apple is not exist for us until we don’t get it out. The things what are not observed are not exist. Some interpretations of quantum mechanics look reality in the same way. This solution radically reduce the needed computing capacity, but there is a problem with it. We need particle level simulation for generating the correct stimuli. In the case of an apple, the simulated apple will act as an apple only if we simulate every biological, chemical and physical activity. After some week, the apple should be robbed, if we compress it, its levier runs out, if we bite it, it gets brown, etc. It is only possible if every physical activities are simulated which are processed in the apple. An easier example, if we bite the apple and close our eyes. The apple won’t be observed, it is not needed to simulate, and it doesn’t exist any more. What will happen if we open our eyes and continue the observation? The apple should be there with the bite, otherwise it will be realized, it isn’t real, but only a simulation. So, the system has to store state of every object, and continue the simulation of the non observed things. We got back to the starting point: we need near infinite storage and computing capacity (particle level simulation) if we want to build a perfect simulated reality. The good news: there is a tricky way to solve this problem. In fact, physical laws are not relevant, but the expectations of the observer. When we open our eyes, we expect the apple to be there with the bite. We can generally say, every act is an experiment where we want to prove we are living in a computer simulation. The experiment failed if the result is different what is expected. So, the simulator should generate stimuli which meet our expectations. In this case we wont be able to prove we are living in a computer simulation, because every result of our experiments will show it is the reality. This is the point where simulated reality meets mind uploading, because the simulator have to read our mind and the easiest way to do it if it is also simulated. So, if the simulator can read our mind, then nothing have to be stored and only observed things (set of stimuli) have to be simulated.
In the rest of the article, I will write about the simulator, and how can it works. I’m not an expert of neuroscience, so what I will write about is built upon what I’ve read in the subject. As I’ve written, I think mind uploading (and mind reading) will be necessary to build a “reality equivalent” simulated reality. Don’t forget, that we are building worlds for neural matrices (uploaded minds), and the goal is to build a network of them with keeping some rules. If we look these minds as matrices, and the simulations as an algorithm which is running on them, then it will be easier to accept things like non-linear time, what I will write about later.
As I’ve written, in a perfect simulated reality, it is enough to simulate things what are observed by us if the simulation meets our expectations. In this case, it is not possible any way to prove it is a simulation. It sounds like the brain should work on reverse way. When we observe the world, our brain converts the sensory information to abstract things, and then memories. When the simulator build the expected reality, this should be processed backward. Remember to the sample experiment with the apple. When we bite the apple, our brain creates a memory about the bite in the apple. When we close our eyes, the apple won’t be exist any more. When we open our eyes, the simulator have to render the apple (a set of stimuli) based on our memories. It is something like reversed perception. I think, our brain can do this, because when we are dreaming, it does something like this. This is also the base of Google’s DeepDream algorithm, which was used to generate that famous hallucination like images. These images are generated by backward processed convolutional neural networks. What we see is the visualized knowledge (memories), which are stored in the network. So, I think, DeepDream is a good name for this algorithm, because the process is something like our brain do when we are dreaming. So, this solution sounds good for building simulated realities which meets the expectations of the observer. But it is not enough to build the whole reality because there are many details which the brain has no information or any memories. Every details which were not memorized, every place which were never visited are unknown things. These details can be built by the simulator from freely generated stimuli and details which are read from the observer’s mind.
Of course, a world like this would be really lonely if there wouldn’t be some other mind besides us. To keep the world consistent, it has to meet the expectations of every mind. If I left my apple somewhere, an other people should find it there. Every observer have to experience the same reality. The simulator have to operate every mind parallel on backward way to build a perfect, consistent reality. It is something like the reality would be a mosaic, and every mind would add a part of it. If we are thinking in “subsystems”, our simulated reality looks something like this: Every minds are connected to an upper, common layer through the sensory system. The minds are getting stimuli from this layer (observe the reality), and also send stimuli which are generated from memories by backward operation of the mind (reality projection). This common layer is responsible for building a valid intersection of these stimuli, and a reality (set of stimuli) which are same for everyone. This layer is responsible for keep the reality consistent, this is why I call it: “consistency machine”. So, the consistency machine is the simulator itself, but it simulates nothing, only creates a valid intersection of the set of stimuli, this is why I think the consistency machine is a better name for it.
In many brain model, the brain is a hierarchical and modular neural structure. Small modules are built from neurons, and other modules are built from these modules, some bigger modules are built from these modules, etc. There are two way communication between the modules, and the conscious information is the result of these. When any stimuli is coming from the sensory system, it activates low level modules, which are activating higher level modules. These higher level modules activate more higher level modules, which respond back, etc. This system is massively parallel, and this gives its huge power. If we see an apple, many low level modules are activating, which are assigned to curves, colors, etc. These modules activates higher level modules, like the “module of a sphere”. The “sphere module” activates more higher level modules, like “planet module”, “ball module”, etc. and the “apple module”. But higher level modules respond back, it cannot be a planet, because it is smaller, it cannot be a ball, etc. After a short time, the “apple module” wins, and the concept of an apple will come up to the conscious level with every connected properties like taste, touch, smell, etc. So, our brain is continuously “rustling”, signals are flashes up and down between modules, and after a short time a concept are manifesting on the conscious level. Thinking is something similar process. From a thought our brain associates an other thought, and new concepts will be generated through the process.
In a case of an apple, we can imagine, how this process works, but can this simple method operates such a complex thing like the human brain? It is hard to imagine how this works, but it is not the model’s fault. We cannot really imagine how this huge, massively parallel networks work.
So, I think, it is an acceptable model of the human brain. I’ve written about the hierarchical model of the human brain to show, how it fits to our simulated reality model. The consistency machine can be simply one or more layer upon the uploaded minds, which are themselves also a set of hierarchical modules. Uploaded minds communicate to these modules through the sensory system like the modules communicate each other inside them. In this system, the sensory system is not a “window to outside”, only a level of the organisation. So, maybe, it is possible to add the consistency machine as new modules to the uploaded minds, and build a “megamind” from them which is able to simulate reality without any other component, using the natural behavior of the mind. In the system of interconnected minds, individuality is on the middle layer, not on the top, and reality is something like a collective, endless dream. A megamind solve the consistency problem on the following way: when individual minds project some components of the reality, the upper layers (what I’ve called ‘consistency machine’) merge them, and send back the generated reality. If this reality is inconsistent with a mind, it sends back the ‘error’, and the ‘consistency machine’ modify the reality. After the end of this communication there will be generated a consistent concept of realty. This is exactly the same way, how an individual mind creates a conscious concept from the inputs which came from the sensory system. This system can solve the consistency problem not only in space, but also in time. As I’ve told, the reality is generated from memories of the minds. If something is not stored in any individual mind, then it is not exist. If nobody has any memory of an event, it is not happened. This is why a megamind can keep consistency in time. If something happened in the past which results inconsistency in the future, the contradiction can go down in the layers of modules, and can change the memories. In this system, memories are the past. So, if memories are changed then the past is changed! It is something like ‘time traveling’. Something bad happened? No problem! Go back in time, and change it! This method can keep the consistency, and also protect the reality, because if any mind finds any prof of simulation, the ‘consistency machine travels back in time’ and make it wasn’t happened. The time is non-linear in this world. The linear time is only the way how individual minds experience the happenings. Time doesn’t exist globally, but only on level of individual minds.
So, what is a megamind? It is a very special living form. One mind, one living thing for an outside observer. It is something like a god in its own universe because it creates and operates it. But it has no individuality, because inside, this superintelligence is splitted into many individual minds. One huge mind which dreams itself as many minds which are living in a simulated reality. This state of consciousness is something what we cannot imagine. It is over the singularity. But what would be the physical form of it? A giant biology-based brain? A huge computer, like a Matrioshka brain? Maybe. But for the end of the article, I have a more extreme variation. How good universe is a megamind?
In the current state of the art, our universe has been created from nothing at many billion years ago by the big bang. It is built from particles which are based on one simple structure: the super string. Every particles are form of these super strings. There are some physical rules what operate he system, and change the state of these particles. Why these rules? Why super strings? etc. Nobody knows. These are the axioms of our universe. From the perspective of math (which is a best perspective, I think), the Universe is a big state matrix (state of the strings), and state changing operations (physical rules) which are operating on it. If we look our Universe from this perspective, a megamind is not really different. A megamind is built from neurons instead of strings (or particles), and there are some rules (like physical rules) which are operates the system. Every neuron has a state, and interact each other by the ‘neural rules’ (this is the ‘physics’ of the megamind), like particles interact each other by the physical rules. I think, if you leave it alone for some billion years, the life can be formed spontaneously like it spontaneously formed in our universe. I think, the evolution can also work in this universe, but here the result is not life in traditional meaning, but the consciousness and the individual minds. This is why I call it ‘abstract evolution’. So, I think, a megamind at least as good universe as ours. Can we say anything about an other universe if we know only our universe? Not really. But just one thing! If we were living in a megamind universe, can we find any proof of it, or we find it exactly the same as our current universe? I wish you good thinking…