Sure it could (in principle) be; its matter all the way down, and there is no lower-level thing of which matter is made. (Though, actually, I think the standard answer to "what is matter made of" under current way of interpreting things would be "energy", but then you could repeat the exercise with "energy" in place of "matter" and its the same issue, mutatis mutandis.)
And i don't see how the term "information" has much descriptive power when discussing nature at its most fundamental level. That may be a way to model it, or describe the physics of it, but that's just an abstraction of whatever that fundamental building block is.
His networks don't require space to exist, they are space. When we think of spacetime, we think of a manifold, and he's saying that what looks like a manifold at a macro level is really just a discrete network at a micro level, and this sort of data structure is more suitable for explaining non-local phenomena, because locality is an effect, not a property, of the model. But for that to work, he has to derive all the current laws from his new model, and he is far from doing that, even though it is a quite fantastic thought experiment.
I think the confusion comes from the fact that at a fundamental level, we do not have the capability to know anything but models and abstractions derived from sense data, and no one is claiming their theories are more than models.
So if Wolfram is correct, then there exists at the lowest level of nature a network, upon which everything else follows. Wolfram is trying to describe reality, something that exists, analogous to the existence of the atom? Do we agree this far?
If these Wolfram-nodes of our networked-reality do indeed exist, how are they connected in unique patterns if there is no "space" between them?
If his theory is not meant to predict something that actually exists, as in the prediction of the atom, well then, i'll bow out of this conversation because it's well and truly beyond my conception of what science is about.
It isn't as if there is an actual line connecting two dots across space.
It's just, there's a set of "points" (there doesn't need to be any things about these "points" other than that they are distinct. You could think of them as urelements I guess.), and another set of "edges", which are each a set of two elements from the first set.
A pair of "points" are "connected" by an "edge" iff the set comprised of those two "points" is in the second set.
This doesn't need a notion of space to work, unless you need like, an idea of space to have collections of things. So unless "the collection of odd numbers" needs an idea of space, then graphs don't need space.
My mistake was thinking that he was proposing something about the nature of physical reality. Ie. that physical reality was literally a network of interconnected nodes at its fundamental level. Something along the lines of macroscopic -> atomic -> sub atomic -> wolfram-nodal. A la, string theory, et. al.
From the replies here, I gather this has nothing to do with physical reality.. he's not describing how this nodal network might be implemented in reality... just that it must be, because the predictions come out correctly.
It's "nothing" as far as we're concerned but despite being intangible, despite being nothing, it has rules and laws that govern matter that traverses it just like every other part of our universe. So what is space itself? What is it composed of? You can't take a quick step outside of the universe to get a look under the hood because you are part of the universe. You can only talk about it in terms of it's rules and behavior–in the abstract.
If we get fundamental enough, we can go below geometry, into algebra.
For a less abstract example, what's the radius of an electron in modern physics?
No, no, no! These graphs are meant to be more fundamental than spacetime. They can change in the sense that there are algebraic rules for stepping them from one state to another, but this step isn't in our time. Our space and time should be generated by operating on these graphs (let's say "stepping" them, as long as we remember that it's not a time-step in our spacetime, but just an algebraic operation).
EDIT> I should say that this whole idea is a model. The question of whether a model is real or not independent of the system being modeled is a philosophical one that we can't really do justice to in an HN comment thread.
The existence of the atom, however, is not what is being predicted. A theory should predict the sensor readings of particular instruments during particular experiments. Those sensor readings are what is real; "The Atom" is the abstraction.
The very idea that "things exist" is an abstraction. A thing exists if we can model it, and that model corresponds with reality.
Over time, physicists have come to take models very seriously (thanks in part to Einstein's 1905 papers). That is, when our model says that electrons act like particles and waves, we assume that electrons really are these odd things that are somewhere in between a particle and a wave.
So, if it turns out that Wolfram's ideas have merit, and there really is an underlying spacetime network which can be used to model and derive all of the known equations of physics (and likely some unknown equations), then at that point we would have to take very seriously the existence of such a network. We would be forced to think of a seemingly continuous spacetime as a special facet or feature of this underlying network, in the same way that we now think of space as a special feature of the more general spacetime.
Yes, but "model" is the key word. If it provides a set of rules which predict the way thing that exist in the world behave, then it models something (or set of things) that exits in the real world.
That realization made me feel pretty stupid and caused a minor existential crisis.
1) Decompose into smaller components and put back together 2) Look at it's structure
It's the diference between describing a cardboard box and a cube (platonic solid).
To describe the first, I have to describe what is cardboard, what is cellulose, what is a cell, what is matter, ... all the way down, and then I hit a wall.
To describe the second, I just need topology.
This definition of space is that space "just is", resembles a network, and that the "stuff" in it is just how we perceive particular local structures.
The network is only a geometrical analogy, there's no "space" between the nodes because the nodes don't represent anything concrete. You can describe the same network algebraically, but then you're left with no pictures to illustrate the article.
For a (really long) discussion on how this simulation parallels physics, check his book, A New Kind of Science, out.
Then maybe you would want to read Aaronson's review of it, just for a balanced perspective.
Then it is a hint that possibly it might be the underlying mechanism of the universe. It's not exactly evidence.
Although to be fair, it's going to be quite cumbersome to discount every other statement in a book almost a thousand pages in length.
What exactly is being networked; what is the "stuff" of the network? He describes the network in terms of connections, which in my mind requires a topology, or space within which to exist; yet space does not apparently exist at this level. If there is no space, then what separates the nodes in the network? If no space separates the nodes, what defines the distinct connections between them?
Yes, i'm completely lost.