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Is the universe compressible? Based on what we know, are there efficiencies to be found in storage or computation of the universe? Because the smallest simulat

Is the universe compressible? Based on what we know, are there efficiencies to be found in storage or computation of the universe? Because the smallest simulation of something incompressible is itself. Assuming the universe is incompressible, it's impossible to simulate the universe in the universe. The smallest computer to simulate the universe would be have the size and energy requirement of the entire universe itself.

newsbinator 6y ago
> The smallest computer to simulate the universe would be have the size and energy requirement of the entire universe itself. There's no reason to think those computers don't exist.
- seventhtiger 6y ago
  They definitely don't exist within our universe.
  - newsbinator 6y ago
    If our universe were a simulation, the computers simulating it would be outside the simulation. We have no idea what constraints those machines would or wouldn't have, since we have no idea what physics they'd be operating under.
    - seventhtiger 6y ago
      That's true. I'm only arguing against partial simulation within our own universe (eg. The Matrix). Any simulation that has a night sky and telescopes must simulate the full big bang and evolution of galaxies just for the people on Earth.
scoutt 6y ago
Why the simulated universe should be the same as the universe outside the simulation? If it's the same, perhaps it's shown to us as a fraction of what's real.
- seventhtiger 6y ago
  It's possible that a bigger universe exists that can simulate ours. However I think whether a simulation of only the perceivable universe is not possible, which means you can't reduce the required computation. See my reply to a sibling comment. If the universe is incompressible then it's definitely impossible to simulate it within itself.
  - scoutt 6y ago
    Sorry. I read incomprehensible instead of incompressible. Perhaps the far universe we perceive and will perceive is not there anymore. It doesn't have to. What we perceive is its light (or electromagnetic/gravitational waves). Objects far away could have been garbage-collected millions of years ago. You don't need to compute them anymore. If the simulation has a limited time to run, then you can create and delete objects while playing with the speed of light to carry whatever information to us. Edit: millions of years ago is not needed. They could have garbage-collected the objects as soon as they complete the time for duration of the simulation. Whatever it is, I would save this information as a template for future simulations.
    - seventhtiger 6y ago
      That definitely would work for Earth today. But note that to simulate observers on Earth today, you had to simulate from the big bang up to (today - light-crossing time from body) for each celestial body. That's significantly larger than Earth, only to simulate Earth today, because tomorrow the entire universe would go dark. Lightspeed gives structure to the computation of the universe but it doesn't reduce the load. Saving templates doesn't reduce the load either, not in the sense I'm considering. It may practically mean that you don't have to run it again, but theoretically if you want to know how much computation got you to this point then you have to count the computation of the templates. So if you had our whole universe at your disposal, and knowledge of all natural laws and processes, and knowledge of the starting conditions, and absolute power over matter and energy, you still cannot simulate our entire universe with anything less than just restarting it. If you wanted to simulated it specifically for some observers, you can free up resources using the lightspeed method but that's a computational debt you cannot pay if you wanted the simulation to continue.
draugadrotten 6y ago
The argument against that was in the article: " the simulation would most likely create perceptions of reality on demand rather than simulate all of reality all the time"
- seventhtiger 6y ago
  This goes back to my thought on compressibility. The article's argument is built on the assumption that some data in the universe can be ignored and the whole computation made more efficient. It's not a trivial assumption. I actually lean towards an incompressible universe, intuitively. If the universe is incompressible, then you may only ignore parts of the data for a finite time. For example, arranging an illusion of the night sky might have taken no computation before astronomy, but as we record the positions of celestial bodies and understand the laws governing them, the computations have to be run retroactively since the big bang. Otherwise the simulation would be inconsistent. So the question is what can you remove from the causal chain from the big bang to this moment? If you think some things are removable, you have to prove that something exists in the universe but does not touch any causal chain humans (or perceivers) may wish to investigate at any point in the future. If nothing is removable, then you cannot choose to not simulate any part of reality based on perception, because whatever you don't simulate may eventually need to be simulated.
WClayFerguson 6y ago
You're forgetting that for the Simulator energy and mass are 'free'. Imagine something like Conway's "Game of Life" where creatures emerge and then start speculating about their own origins. Their measurements of energy would mean nothing to us. Entropy perhaps, but not energy.
- seventhtiger 6y ago
  Energy and mass are free, but computability is fundamental. If denizens of the game of life discover their natural laws and calculate the computations their universe runs on, theoretically it should be the exact some as ours. This example is great. My main point is that due to the laws of their universe, they will never be able to simulate any area of it in a smaller area, because the Game of Life isn't compressible.
  - WClayFerguson 6y ago
    I don't know what compressible means. If you mean the information content of the universe, then well, anything that is not pure random is generally compressible. What evidence is there that physics is 'compressible' rather than simply 'uncertain'?
    - seventhtiger 6y ago
      By compressible I mean containing any information not necessary to compute the next step.
      - WClayFerguson 6y ago
        I'm a believer that every particle and wave in the universe is being computed whether it's being observed or not. People who think QM is about 'consciousnesses' are generally not even deeply even conversant about QM, and have read some 'woo woo' books, and gotten confused. Belief that consciousness is somehow more fundamental than 'brain physiology' is essentially a kind of solipsism and is completely unfounded in facts or experiments. If we're in a sim, it's Physics rules that are being "run" and the existence of brains is purely emergent.

newsbinator 6y ago

> The smallest computer to simulate the universe would be have the size and energy requirement of the entire universe itself. There's no reason to think those computers don't exist.

seventhtiger 6y ago
They definitely don't exist within our universe.
- newsbinator 6y ago
  If our universe were a simulation, the computers simulating it would be outside the simulation. We have no idea what constraints those machines would or wouldn't have, since we have no idea what physics they'd be operating under.
  - seventhtiger 6y ago
    That's true. I'm only arguing against partial simulation within our own universe (eg. The Matrix). Any simulation that has a night sky and telescopes must simulate the full big bang and evolution of galaxies just for the people on Earth.

scoutt 6y ago

Why the simulated universe should be the same as the universe outside the simulation? If it's the same, perhaps it's shown to us as a fraction of what's real.

seventhtiger 6y ago
It's possible that a bigger universe exists that can simulate ours. However I think whether a simulation of only the perceivable universe is not possible, which means you can't reduce the required computation. See my reply to a sibling comment. If the universe is incompressible then it's definitely impossible to simulate it within itself.
- scoutt 6y ago
  Sorry. I read incomprehensible instead of incompressible. Perhaps the far universe we perceive and will perceive is not there anymore. It doesn't have to. What we perceive is its light (or electromagnetic/gravitational waves). Objects far away could have been garbage-collected millions of years ago. You don't need to compute them anymore. If the simulation has a limited time to run, then you can create and delete objects while playing with the speed of light to carry whatever information to us. Edit: millions of years ago is not needed. They could have garbage-collected the objects as soon as they complete the time for duration of the simulation. Whatever it is, I would save this information as a template for future simulations.
  - seventhtiger 6y ago
    That definitely would work for Earth today. But note that to simulate observers on Earth today, you had to simulate from the big bang up to (today - light-crossing time from body) for each celestial body. That's significantly larger than Earth, only to simulate Earth today, because tomorrow the entire universe would go dark. Lightspeed gives structure to the computation of the universe but it doesn't reduce the load. Saving templates doesn't reduce the load either, not in the sense I'm considering. It may practically mean that you don't have to run it again, but theoretically if you want to know how much computation got you to this point then you have to count the computation of the templates. So if you had our whole universe at your disposal, and knowledge of all natural laws and processes, and knowledge of the starting conditions, and absolute power over matter and energy, you still cannot simulate our entire universe with anything less than just restarting it. If you wanted to simulated it specifically for some observers, you can free up resources using the lightspeed method but that's a computational debt you cannot pay if you wanted the simulation to continue.

draugadrotten 6y ago

The argument against that was in the article: " the simulation would most likely create perceptions of reality on demand rather than simulate all of reality all the time"

seventhtiger 6y ago
This goes back to my thought on compressibility. The article's argument is built on the assumption that some data in the universe can be ignored and the whole computation made more efficient. It's not a trivial assumption. I actually lean towards an incompressible universe, intuitively. If the universe is incompressible, then you may only ignore parts of the data for a finite time. For example, arranging an illusion of the night sky might have taken no computation before astronomy, but as we record the positions of celestial bodies and understand the laws governing them, the computations have to be run retroactively since the big bang. Otherwise the simulation would be inconsistent. So the question is what can you remove from the causal chain from the big bang to this moment? If you think some things are removable, you have to prove that something exists in the universe but does not touch any causal chain humans (or perceivers) may wish to investigate at any point in the future. If nothing is removable, then you cannot choose to not simulate any part of reality based on perception, because whatever you don't simulate may eventually need to be simulated.

WClayFerguson 6y ago

You're forgetting that for the Simulator energy and mass are 'free'. Imagine something like Conway's "Game of Life" where creatures emerge and then start speculating about their own origins. Their measurements of energy would mean nothing to us. Entropy perhaps, but not energy.

seventhtiger 6y ago
Energy and mass are free, but computability is fundamental. If denizens of the game of life discover their natural laws and calculate the computations their universe runs on, theoretically it should be the exact some as ours. This example is great. My main point is that due to the laws of their universe, they will never be able to simulate any area of it in a smaller area, because the Game of Life isn't compressible.
- WClayFerguson 6y ago
  I don't know what compressible means. If you mean the information content of the universe, then well, anything that is not pure random is generally compressible. What evidence is there that physics is 'compressible' rather than simply 'uncertain'?
  - seventhtiger 6y ago
    By compressible I mean containing any information not necessary to compute the next step.
    - WClayFerguson 6y ago
      I'm a believer that every particle and wave in the universe is being computed whether it's being observed or not. People who think QM is about 'consciousnesses' are generally not even deeply even conversant about QM, and have read some 'woo woo' books, and gotten confused. Belief that consciousness is somehow more fundamental than 'brain physiology' is essentially a kind of solipsism and is completely unfounded in facts or experiments. If we're in a sim, it's Physics rules that are being "run" and the existence of brains is purely emergent.