Wolfram’s space-time
Recently in his blog, Wolfram mentioned a new interpretation of space and
time. http://blog.wolfram.com/2007/09/my_hobby_hunting_for_our_unive.html#more
Let’s first examine two current interpretations of space.
“Normally in physics one thinks of space as some kind of background, in which
matter and particles and so on separately exist” writes Wolfram. Some regard
space as a container in which events happen, that existed even before the Big
Bang, and we evolve in it. Poetically speaking, the Big Bang might be regarded
as a fertilization of a primordial uterus.
Mandelbrot draw our attention to the possibility that space
might be a fractal with its own geometry. Now Wolfram proposes that space
might be a network and cautions us not “to imagine that the points
in the network have actual defined positions in some background space.” He
then adds “What's interesting, though, is that when a network gets big enough,
its combinatorics alone can in effect define a correspondence with ordinary
space.”
What about time? :” Current physics tends to say that time
is just like space--just another dimension.” In other words time is a container
extension into a higher dimension. Such a simple extension seems not to work in
a fractal space. How then define time in a fractal space? I leave it to you as
an exercise in a thought experiment.
Wolfram has a another suggestion. Suppose that space is a network of programs.
“In programs, moving in space might correspond to looking at another part of
the data, but moving in time requires executing the program.” “For networks,
pretty much the most general kind of program is one that takes a piece of
network with one structure, and replaces it with another.”
“But now we're deriving something like that for the universe: we're saying
that these networks with almost nothing "built in" somehow generate
behavior that corresponds to gravitation in physics.” This is Wolfram’s space.
Actually it is a space-time. The programs are the space
while each executes its own time.
Similar space-times are inherent in life.
Wolfram: ”Special and general relativity are things that physicists normally
assume are built into theories right from the beginning, almost as axioms (or
at least, in the case of string theory, as consistency conditions). The idea
that they could emerge from something more fundamental is pretty alien” Yet
Wolfram believes that ”. . .our whole universe and its complete history could
be generated just by starting with some particular small network, then applying
definite rules.” I hope that he does not mean our physical universe but the
way we interpret it.
More
on Wolfram’s biological thinking