mitchell porter said:
I thought Wolfram was just proposing to base physics on a kind of cellular automaton. Is he using AI to search the possible rules? Where does he talk about this?
Read the three papers and his book. It also helps to take a moment of reflection and look at this, not from the perspective of a contemporarily practicing theoretical physicist, but instead from the perspective of a modern applied mathematician, computational scientist or data scientist that is knee-deep within the modern deep learning revolution (
NB: I'm fairly ankle-deep in this as a consequence of supervising (under)graduate students doing such research).
HBrown said:
I read through his initial post.
He's clearly excited about some ideas, but they are still vague, and to some extent he seems aware of this.
He seems to make the common mistake of being just vague enough about some important pieces that he can oscillate between different concepts as it suits his hand waving. For example how he wants to extract physical notions from an abstract graph, even simple things like distance change flavor in various hand wavy descriptions.
In the end, he has an idea that he enjoys, and he has resources to chase them.
It doesn't sound compelling to me, but arguing motivations and what sounds plausible is pointless, he's going to spend his time on it regardless. So I guess I wish him luck. Looks like a long shot.
S.G. Janssens said:
If this is indeed what he believes his "program" is capable of, then it is not just comfortably vague, or "too good to be true" (post #11), but it is also blatantly arrogant. Based on his "New Kind of Science" I did not expect anything less.
I understand your skepticism and actually appreciate it in order to paint a contrast. What Wolfram in his enthusiasm doesn't emphasize enough is that his method doesn't only produce a "unique correct answer", but instead also a veritable multitude of answers; a selection procedure (from mathematical physics/condensed matter theory flavored statistical physics) is then used to trim this forest down to find the "fittest" answers (
NB: as in survival of the fittest). Subsequently these fittest answers are then used axiomatically to rederive known physical theories, as a kind of second order selection method. All of this is quite typical hybrid methodology in modern machine learning.
The above hybrid methodology is a highly creative but very specific application of evolutionary algorithms applied to axiomatization applied to derivation from first principles applied to theory construction, which each are of course each tried and true methods. What isn't conventional knowledge to physicists is that this hybrid method isn't actually new; it is known as "experimental mathematics" and has actually been quite conventional since the 80s within applied mathematics and engineering under another moniker namely, "dynamical systems theory".
A presentation or communication problem which often arises is that most physicists (and many mathematicians and computer scientists as well) simply aren't accustomed to or familiar with this type of research and therefore are unable to recognize it when they come across it and so end up reliably misjudging its scientific value. What
is truly novel is that Wolfram seems to have automated a large part of the experimental mathematics methodology, and so actually given it a rigorous grounding, when before it was seen as more of an art form, i.e. like skillful experimentation often is seen.
In any case, the importance of this discovery cannot be stressed enough: what Wolfram has discovered is a revolution not just for theoretical physics, but actually for pure mathematics as well; namely Wolfram has laid bare, in a purely axiomatic format, that there are as of yet unidentified existing links between the theory of analysis, computational complexity theory and algebraic geometry which is not generally recognized by either the physics literature or the physics community, apart from a handful of subfields within mathematical physics.
In fact, the last time that I can recall off the top of my head that such a huge mathematical discovery was actually done in mathematical physics proper on the basis of deepening the understanding of older theories was when Euler, Lagrange and Hamilton reviewed Newtonian Mechanics using extremely sophisticated mathematics for their time and ended up inventing Analytical Mechanics as well as emphasizing and/or literally inventing the associated mathematical disciplines.
martinbn said:
If this is an accurate description then it sounds like a meta-theory, not physics. Not so sure if this is useful. The input is theories that are well understood, the output is theories that are also well understood, but only if you can recognize them otherwise you get all kinds of possibilities without any hope of filtering a useful one.
May be I should have been more specific myself. By a problem I mean the type of problems physicists solve. Say heat conduction in a rod, a vibrating membrane, an orbiting planet, or anything like that. Any example at all. How does his black box deal with it?
Those actually aren't "physics problems", but instead
applied physics problems i.e. actually engineering problems and therefore, generally speaking, completely uninteresting to the discipline of theoretical physics directly; of course, this doesn't mean they are uninteresting to experimental physics, since such problems obviously can lead to better experiments. However that is clearly a matter of secondary concern for the enterprise of theoretical physics - especially when experimental physics has already reached the degree of sophistication as today - and it is even of tertiary concern for mathematical physics.
More directly, Wolfram's black box is a complete overkill for such applied physics problems since such problems - by their very hands-on nature - literally require to be defined within an already given mathematical framework; Wolfram's blackbox is instead for addressing problems with entire frameworks themselves, i.e. by actually removing what is given. Actually doing such a thing successfully literally requires a seasoned expert in theoretical physics and/or mathematical physics, e.g. a practicing physicist at the level of
John Baez and often in that age category as well.
Suffice to say, Wolfram's earlier invented, pedestrian tools - i.e. Mathematica and WolframAlpha - tend in almost all cases to be sufficient for tackling most applied physics problems with a fair amount of effectiveness such that even most undergraduates are typically capable of quickly making some headway towards finding solutions to such applied physics problems; difficult outstanding applied problems from this perspective are merely remaining 'low hanging fruit' which require at most a few grad students and perhaps a good doctoral advisor.