Hello! My name is Joel Dobrzelewski and I'm newcomer to the list.
I'm still looking through the archived messages, but so far it looks like a
very good match with what we do. I'm excited to see others working in this
area and wish I had found you sooner!
Anyway, I represent a small group of people who believe that in fact all
universes do exist and are computed by some very simple structures known as
"minimal cellular automata".
This concept was developed by my good friend, Plamen Petrov in Bulgaria.
Together we run the Digital Physics web site:
(I should note: Not all participants in our organization agree with this
Plamen and me on this issue. What the larger group has in common is the
belief that the universe is discrete, not continuous.)
In a nutshell, a minimal cellular automaton is a regular cellular automaton
(e.g. Conway's Game of Life) that has *no* unreachable configurations,
starting with a finite initial configuration.
Or, stated another way, a minimal cellular automaton generates *everything*
(all finite configurations).
A more precise definition can be found here:
So in this case, Conway's Game of Life is probably a poor example, because
it in fact has many unreachable configurations. But at least it is the
automaton that most people are familiar with.
A better example is the very simple one-dimensional, three-neighbor
automaton known as Rule-30:
This simple rule appears to generate ALL finite 1D strings.
What does this mean?
Without knowing anything about the "natural" world, Rule-30 (starting with a
single non-blank bit) - all on its own - generates every possible book,
symphony, or email message imaginable (or unimaginable!).
Furthermore, this process is reversible - thus preserving the work done by
the automaton and providing a mechanism for reconstructing the past (i.e.
microscopic reversibility of nature).
It is our belief that there exists a 3D version that is not only minimal
(generates everything) but also universally computational. Meaning... it
generates all PROGRAMS as well.
But the advantage here is that we can more easily envision the existence of
such a miraculous object like a minimal cellular automaton than, say, a
Universal Turing Machine. Cellular automata naturally implement physical
universes without any interpretation. The bits merely exist... and we can
see them with our digital eyes - and the patterns they generate.
It is my belief that the Universe we inhabit is the one mathematical object
that all sentient creatures can deduce exists, and that the minimal cellular
automaton is the solution.
Certainly, there is more work to be done. But I feel we have a good start
and a solid foundation. Hopefully the rest will come in time.
Well, I hope our two groups will find some common ground. From what I can
tell, our work most closely parallels that of Mr. Juergen Schmidhuber.
Juergen - do see what we are trying to do? I must admit my understanding of
your papers is limited, as I don't have a lot of experience reading
scientific papers like these. But at least, it looks like we're on a
similar track. Yes? No?
Anyway, it is good to find you good people. I hope we will have much to
talk about! (perhaps everything!!)