3 ms·

Along similar lines, I've wondered if it's possible to prove "any observing entity (e.g. a human) cannot possibly fully understand the system within which it is

Along similar lines, I've wondered if it's possible to prove "any observing entity (e.g. a human) cannot possibly fully understand the system within which it is contained" .. any complete knowledge of a system should necessitate a larger system.

Xcelerate 12y ago
I've always wondered this as well. Consider a finite collection of atoms consisting of a human and an environment. For simplicity, assume these atoms move classically. The human is a subsystem, and since the entire system involves deterministically, there is only a limited number of configurations that the human subsystem can realize within the environment. If a "human" is what is necessary to comprehend reality, then there are aspects of the system that cannot be realized by the subsystem, since there are far more states available to the total system. Then again, I could just be rambling.
- danbruc 12y ago
  I would argue it depends on the nature of the system. If the system follows (simple) rules then you can likely compress the description of the system into something that fits into a (small) subsystem. If the system and its behavior is a uncompressible mess this will not work out. Up to now, I would say, our universe with all its relatively simple laws of physics looks pretty structured and easily compressible.
- hasenj 12y ago
  I don't think this works. You don't have to encompass everything about the universe in your mind. You can just comprehend a formula that allows you in principle to calculate any part of it that you need. Think of a fractal. http://en.wikipedia.org/wiki/Mandelbrot_set http://en.wikipedia.org/wiki/Mandelbrot_set
evanb 12y ago
There's some relevant discussion on this old thread: https://news.ycombinator.com/item?id=7244476 https://news.ycombinator.com/item?id=7244476
rndn 12y ago
It’s easy to prove "we don’t know that" since maybe it is possible to introspect our universe. For example, suppose someone interacts with some quantum system and it unexpectedly outputs a binary string. It turns out that this string can be interpreted as a command-line interface where one can access the states of individual particles and inspect the running process. Given the program code of our universe is reasonably short, we could possibly fully understand the system from within.

Xcelerate 12y ago

I've always wondered this as well. Consider a finite collection of atoms consisting of a human and an environment. For simplicity, assume these atoms move classically. The human is a subsystem, and since the entire system involves deterministically, there is only a limited number of configurations that the human subsystem can realize within the environment. If a "human" is what is necessary to comprehend reality, then there are aspects of the system that cannot be realized by the subsystem, since there are far more states available to the total system. Then again, I could just be rambling.

danbruc 12y ago
I would argue it depends on the nature of the system. If the system follows (simple) rules then you can likely compress the description of the system into something that fits into a (small) subsystem. If the system and its behavior is a uncompressible mess this will not work out. Up to now, I would say, our universe with all its relatively simple laws of physics looks pretty structured and easily compressible.
hasenj 12y ago
I don't think this works. You don't have to encompass everything about the universe in your mind. You can just comprehend a formula that allows you in principle to calculate any part of it that you need. Think of a fractal. http://en.wikipedia.org/wiki/Mandelbrot_set http://en.wikipedia.org/wiki/Mandelbrot_set

evanb 12y ago

There's some relevant discussion on this old thread: https://news.ycombinator.com/item?id=7244476 https://news.ycombinator.com/item?id=7244476

rndn 12y ago

It’s easy to prove "we don’t know that" since maybe it is possible to introspect our universe. For example, suppose someone interacts with some quantum system and it unexpectedly outputs a binary string. It turns out that this string can be interpreted as a command-line interface where one can access the states of individual particles and inspect the running process. Given the program code of our universe is reasonably short, we could possibly fully understand the system from within.