2016-12-16

Meaning, quantum process and inscrutability

The analogy between meaning and measurement in quantum mechanics is something that has been on my mind for quite a while, as attested by a couple of posts from the early years of this blog. I'm therefore walking here an old path, but with a couple of new things in mind, including a quite radical shift in my viewpoint on signification since 2005, and the current lively debate around inscrutability of machine learning algorithms. The following points sum up where I stand today.

Meaning is a process

The Web has been a wide-scale experience in applied semantics, and more and more, in applied semiotics. Our interaction with the Web is using signs, the primordial and main ones being those weird identifiers called URIs. For years, I have, with many others, struggled with the thorny issue of what those URIs actually identify, or denote, or mean, or represent, spent hours in endless debates with Topic Maps and Semantic Web people to figure the difference or similarity between subjects and topics of the former, and resources of the latter. Eventually fed up with those intractable ontological issues, I decided to keep definitely agnostic about them, to focus on the dynamic aspects.

To the question What does it mean? I answer now It means what it does. In other words, the meaning of a URI on the Web is a process, whatever happens when you use it. This process can be technically described and tracked. It includes query processing, client-server dialogue, content negociation and federation, distributed computing, and more and more artificial intelligence. But from the end-user viewpoint, the URI are now hidden under the hood, the interface with the Web using natural language signs like words and sentences, written or spoken, and more and more those application icons on the touchscreen of our mobile devices, simple signs bringing us back to hieroglyphs and magic symbols. Meaning on the Web is the (more and more complex) processing of (more and more simple) signs.

Is this conception of meaning specific to the Web? If one looks closely, the answer is no. Meaning of (often simple) signs outside the Web is also the result of a (often complex) process. Whatever its nature, a sign means nothing outside a process of signification. The Web has simply given us an opportunity to explore this reality in-depth because we have engineered those process, whereas outside the Web those process are given, we use them without question on a daily basis, and we are not aware of their complexity. The more complex the Web is becoming, and the simpler the signs we use to interact with it, the closer it seems to our "natural" (read : pre-Web) semiotic activity.

Meaning process is similar to quantum process

The evolution of the Web is also tackling the difficult issue of meaning in context. The process triggered by the use of a sign is almost never the same. The time of the query, the nature state of your client device, the state of the network, your user preferences, interaction history and rights of access, the content negociation ... make every other URI resolution a unique event. Among all possible meanings, only one is realized.

Here comes the analogy with quantum mechanics. Among all possible states of a system, of which probability distribution might be known with great accuracy, only one is realized in any quantum event. Before the event, the system is described as a superposition of all its possible states. The reduction of this pack of possibles to one realization is technically called collapse of the wave function.

Samely, before you sent a query using a sign, before you click your email icon application, everything is possible. You might have mail or not. Your spam filter might have trashed an important contract. Whatever happens means the collapse of all possible states, but one. This collapse process defines the meaning of the sign at the moment you use it.

The same way in natural conversation you would say "Will you pass me the bowl?" and of all the possible meanings of "bowl" in your interlocutor's mind, all will collapse to zero but the one which indicates the only bowl sitting on the kitchen's table in front of you.

Both meaning and quantum process are inscrutable, and it's OK

The inscrutability of reference has been discussed in depth by Quine in Word and Object (1960). Quine wrote mostly before our world of pervasive information networks, before the Web, and although he died at the eve of the 21st century, he did not write anything about the Web, unless I miss something. Which is too bad, because "Word and Object" in the framework of the Web, and singularly the Semantic Web, translates easily into "URI and Resource", but maybe Quine was a bit too old in the early days of the Web to apply his theories to this new and exciting field.

Therefore, unless I miss something, Quine did not address the reference in the dynamic aspect we discuss here. Reference is inscrutable because it's a process which involves each time a sign is used a very complex and (either in theory or in practice) inscrutable process. In human natural interpretation of signs, this meaning process involves several parts of our brains and perception/action systems in a way we just barely figure. The signs we send to the network are and will be processed in more and more complex and practically inscrutable ways, such as the machine learning algorithms we already see implemented in chatbots.

Quantum process have been known since about one century ago to be inscrutable, although some of its famous founders did not like this frontal attack against determinism at the very heart of the hardest of all sciences. Albert Einstein among others was a fierce opponent to this probabilistic view of the world, defended by quantum mechanics orthodox interpretation, and used a lot of time and energy to defend without success some "hidden variable theory". Inscrutability was here to stay in physics. It seems also here to stay in semiotics, and in information systems. This is a singular convergence, which certainly deserves to be further considered and explored.

[Further reading might include works by Professor Peter Bruza (Queensland University of Technology, Brisbane, Australia) such as Quantum models of cognition and decision or Quantum collapse in semantic space : interpreting natural language argumentation.]