^^^ IF our universe is a simulation, most of what we observe could simply be programmed feedback to make us think there is a huge universe out there. IF we are in a simulation, we cannot know about computing power & possibilities in the genuine world. <>
All the size and energy of the universe. The program would be fractal. We might be able to create a very small model of the universe but it would not be functional because eventually we would still run out of space required to account for the ~90 % of space within individual particles, even at Planck scale.
^^^ IF we are in a simulation, we cannot know anything about science & technology in the genuine world. <>
As Tegmark explains, even in a purely mathematical simulated Universe, all values and functions would remain the same in the simulation as in what we perceive as the real world, and our science would not be any different than what it is now. In a computer simulation, if a rock falls on you and kills you, the same mathematical functions are involved in the real world. If you run into a wall in a simulation, it is the same as running into a wall in reality. You would still have to go around or jump over it. The actual values and functions are the same. Computer programs use the same mathematics as the real world. Only the form of energy used is different. Instead of electricity in a simulation, the real world uses electro-chemical energy The difference lies in the ability to think, feel, and act independently. In a simulation it is the gamer who controls the simulated person, in a mathematical simulated world the gamer's sentience would be an aware simulated person. Think of it this way. E = Mc^2 holds in both worlds
This may be of interest https://www.ted.com/talks/anil_seth_how_your_brain_hallucinates_your_conscious_reality The one thing I have a problem with is the assertion that sentience depends on our internal regulatory brain functions. As Seth explains, we have no sensory experience of our organs, only if they go wrong. We experience pain in our side when the liver is damaged or we experience stomach pain, when we have an upset stomach. But normally we are not consciously aware of our internal organs, unless something goes bio-chemically wrong. OTOH an AI (computer) does the same thing, except it experiences it's internal parts electronically and when something electronically goes wrong, we already have self-diagnostic computers which warns itself (and us) that a specific board or connection is faulty. IMO, if such a self-diagnostic ability is sufficiently sophisticated, could that not be considered as a form of sentience. The computer may not experience pain, but it can certainly diagnose itself if it is functioning at peak performance. I think that may be compared as similar to internal body consciousness of bio-chemical discomfort in living organisms. It just employs a different method, but many living organisms function by different conscious methods than other living organisms.
^^^ Tegmark is referring to simulations we might produce. I am referring to the possibility that we are in a simulation. Further, IF we ever are able to make good simulations, we should be able to make 1 in which a 50 ton boulder falling on a person would not kill them & people will be able to pass thru walls & many other such possibilities contrary to our "real" world. The "people" in that simulation would have no way to know what life & science is like in our world. It is not a matter of mathematics being different. It is a matter of what the programmers are able to do & what they decide to do. There is no reason to think simulations will have to be exact reflections of the world which produces them. If we (or they) are able to make only 1 simulation, how that will turn out is unpredictable. If we (or they) are able to make multiple simulations, a good guess is that a few will closely reflect the "real" world & most will be very different. Think of it this way : You cannot possibly know that. <>
^^^ Sentience is 1 of those things which are very difficult to define. I think tho that when we have sentient machines, intelligent people will be able to understand that they are sentient. <>
I thought we were talking about a simulation of the Universe as we experience it. IOW. the experience of a 50 ton boulder would splatter your simulated body into a single bloodstain, with perhaps a few scattered bones as evidence of the actual force of impact. My point was that the very same universal laws would apply . They are all mathematically connected and if you were to try and change one of the natural mathematical functions, the entire program would crash, because it's all connected. Suppose we would make gravity behave different, what would happen to the simulation? Could we fly by flapping our arms? Would the earth still circle the sun?
^^^ I thought we were talking about any possibility of simulating a universe. Sorry for the misunderstanding. I just checked the OP. It refers to a simulation of the universe & I referred to the possibility that the universe IS a simulation. <>
Oh, if we could simulate an alternative reality, that would be awesome. I've seen some sci-fi movies, that were pretty cool. Time travel, warp speed, space bars. I always liked the movie "Total Recall".
As I understand Tegmark, he proposes that the Universe does not have some mathematical properties, but has only mathematical properties, i.e. values and mathematical functions. It's just that at our scale of perception things look and feel solid, but that our physical experience is just a result of Relativity. At Planck scale there are no physical things, just fuzzy probabilities. Hang on, let me see if I can find a Renate Loll lecture. I read about the theory of Causal Dynamical Triangulation (CDT) and the hypothesis that it is responsible for the evolution of the fabric of space itself, plus the fact that this function is background independent and is not in conflict with QM or GR, the inherent simplicity able to yield the most complicated physical structures really has affected my worldview.[ https://www.youtube.com/watch?v=Rstu3nGdZLs and Renate Loll's interesting presentation. https://www.youtube.com/watch?v=fv2gBjQ8xIo
^^^ IF we ever have the ability, we will probably make a simulation in which Germany&Japan won WW2, 1 with wizards, fairies, elves & unicorns & 1 with Superman, Batman & Wonder Woman. 1 with aliens visiting Earth & 1 with humans colonizing far parts of the universe. The number of different 1s would depend only on the number we can make. I like Total Recall except for the very last part which has bodies being messed up by the bad atmosphere then when the atmosphere is stabilized they are magicly back to normal. <>
^^^ I am downloading the video & will probably watch it within a couple days. Those things make me suspect we are in a simulation. <>
LOL, yes, but then the movie leaves you hanging, wondering if the experience was real or just a mental trip, while he was all that time sitting in the chair. Remember he picked his own adventure and characters.
^^^ It has been so long that I do not recall all the specifics of that book & do not know how close the book & movie are but I do recall that Phillip K Dick liked to screw around & leave us wondering. Which is mostly good. I like to do that too. Funny, most people who read my stories before they are published say "But you did not explain this & that" while most (who I hear from) who read them after they are published do not say that. <>
There are at least 3 types of simulation possibilities. 1 - As in Star Trek, 1 or more people go into the simulation. Their bodies & minds are in the simulation & normally, they know they are in a simulation. Normally, in Star Trek, they have control of the simulation but there might be a version with which the person(s) in the simulation have little or no control over it. 2 - A person's mind goes into the simulation but not the body and/or the brain is given feedback which makes it seem they are in a simulation. This too could be with very much control or with very little control. 3 - Everyone in the simulation is a part of the simulation & not from outside the simulation. I do not think there could be a version of this in which anyone in the simulation can have any control. <> Can someone replace my foozewizzle circuit?
Unless you are talking about your computer, I'm afraid not. Actually we always live in a simulation spontaneously created by our brain. In fact Anil Seth proposes we are constantly hallucinating, some of which we can control, some not. https://www.ted.com/talks/anil_seth_how_your_brain_hallucinates_your_conscious_reality