"If Can Can, If No Can No Can."

"Can can," as I see it, expresses that something is possible, "no can no can" that it is impossible. As the truth of things is approached, the less official the road to it seems. In a neat twist of affairs, if constructor theory is true, then the above phrase from Hawaii's pidgin may have the distinction of expressing the fundamental nature of reality.

In the "Science of Can and Can't," Dr. Chiara Marletto explores the nature of possibility as it relates to the traditional conception of physics. The main focus of her work concerns "the counterfactual properties of physical systems." Turns out that the possible and the impossible, also known as the counterfactual, have been neglected in physics. Marletto doesn't just say that this has been wrong, she says that our understanding of reality has been impoverished as a result.

As I was reading her book, I thought of another person deeply engaged with questions of counterfactuality, the philosopher David Lewis. Lewis pioneered the metaphysical domain of modal realism. His full acceptance of the reality of possible worlds was controversial, to say the least, among fellow analytic philosophers like Saul Kripke and Robert Stalnaker, neither of which minced words in saying how wrong headed Lewis was.

While there are some obvious differences between modal realism and constructor theory, top among these is that possible worlds are causally closed and can't interact with each other. Extended modal realism, developed by Takashi Yagisawa, does seem to take a step in the direction of the constructor theory by allowing objects to have modal and non-modal properties. Thus, what's possible is itself a modal property that can be categorized according to the type of possibility: logical, physical, metaphysical.

What fascinates me is how Marletto's work potentially provides a massive unification of domains traditionally thought to be separate. Here I'm thinking not just of the huge unification that she details between information theory and thermodynamics, which already is revolutionary, but a larger one that includes an extension and deepening of modality in general.

As a developer who arrived late at the React party, I've had the priviledge of being like a kid at the Toys-R-Us (RIP) frantically loading the cart with toys before the give-away ends. From a regular user's perspective, the 2021 Web doesn't seem fundamentally different from the 2011 Web, yet something equivalent to Marletto's revolution happened in the interveening years.

The revolution was led by the React team at Facebook and their invention of the virtual DOM. The DOM in browsers is the environment for all apps and websites, but also all of their granular elements, from the HTML tags, to the CSS selectors, to the Javascript functions. We could say that the invention of the virtual DOM that components intereact with is the counterfactual part of the actual DOM. In the terminology of constructor theory, there's only one DOM, but it has actual and counterfactual properties.

In my view, what React did was complete the deep identity of browser DOMs by giving them their counterfactual properties. One of the major criticisms of React when it was first being used was skepticism that adding a virtual DOM would make apps more efficient. Not only was this proven a false worry in practice, it has become the standard for developers to think in terms of components and their state changes first to ensure that the flow of data isn't bottle necked by the inefficient rendering that afflicted previous incarnations of browser DOMs.

Where do we go from here? I, for one, am deep into the weeds of the Next.js framework developed by Guillermo Rauch and his team at Vercel. Next is fascinating because it seeks to keep the fundamental layer of React intact while making its interactions with the whole DOM more efficient for data flow. Philosophically, I'm curious how Marletto's "Science of Can and Can't" will be received. I'd imagine that, as in all revolutions in these accelerationist times, things will take a while to seep into the culture. But, there's no denying that her work is a harbinger of exciting things as we move from "no can no can" to "can can."

Reading:

Marletto, Chiara. The Science of Can and Can't: A Physicists's Journey Through the Land of Counterfactuals. Penguin: Random House, 2021.