Questions about information limits in the Universe

[stuartmacg]

For a hammer all problems are nails, and for a signal processing animal like me, it is all about information

The laws of mechanics limit the info needed to describe/define motion.

The limited number of finite sized stable elements, built using smaller number of particles, limit the information needed to describe a lump of stuff.

Quantum mechanics limits the info needed to describe the behavior of particles.

Finite space and time for the universe limits the amount of information needed to define it.

I don't know if relativity has similar info reducing effects?

Does this suggest that the information needed to define the universe (over space and time) may be finite, though of course somewhat large?

 

[fresh_42]

... and for a signal processing animal like me, it is all about information

Are we talking about transmitters (atoms), form (impulses and waves), information (meaning), or rules (formal languages), or are we talking just about all of them at the same time without ever defining what we mean or specifying any terms we use?

 

[Borek]

The laws of mechanics limit the info needed to describe/define motion.

Does it?

I mean - I more or less understand where you are coming from, there is a limited number of numbers required to describe the system (plus, as fresh pointed out, some rules). BUT: how precisely do we need to know these numbers? FP representation is always just an approximation, in general an exact value needs infinite number of digits, making amount of information required infinite.

(Two beers after a dinner, don't expect too much rigor from me )

 

[fresh_42]

Does this suggest that the information needed to define the universe (over space and time) may be finite, though of course somewhat large?

The universe itself is at last the system that carries all information, and as far as I can see, i.e. without knowing the dark sector, it is finite. Question answered.

 

[stuartmacg]

Without the rules of motion, the motion of a single object would require infinite information over a finite space and time. To be more precise here we would probably need to add the uncertainty principle, to limit accuracy.

I am not clear however that the laws/rules/models so far identified imply the total is finite.

 

[Baluncore]

To define something precisely, would require infinite information. Then you could solve the three body problem, and predict the butterfly effect.

We are happy to limit the number of Fourier coefficients, and we accept the approximation. That does not require infinite information.

 

[stuartmacg]

not sure: the definition would have a time dimension - quantum uncertainty alone would require the (compressed) info to be spread (associated with locations) over time, as well as space.

Distributed butterfly updates, possibly spread through a linear transform or etc., should deal with info loss in such systems, over the finite duration of the universe. I did say a lot of info would be needed, but it may not be unbounded?

That said, I am only the lazy fool hoping to prod some answers from the hard working wise men on this forum, and have some fun.