Marvin Minsky

Marvin Minsky has passed away from us last night. Right before I got the sad news, I had spent an hour in a conversation with a friend in on the other side of the continent, discussing how Marvin has influenced our work and our way of looking at what makes us human.

(Marvin Minsky, me and Cosmo Harrigan, at his house)

Marvin Minsky was quite certainly the most influential thinker about the nature of our minds in recent history. When psychology focused on behavior because it had failed to develop methods to study mental processes, thought and intentionality, Marvin realized that minds are information processing systems, and we can make progress in understanding them by building computer models of these processes. Minsky became the founding father of this new computational science of the mind: Artificial Intelligence. 

Marvin Minsky did not think that minds are governed by a simple general principle, like neural learning, or homeostasis. The richness and depth of what makes us human requires an enormous complexity of cooperating and often self-regulating mechanisms, which Minsky started to address in his famous "Society of mind" theory. He pushed hard against approaches that he considered too simplistic, and inadvertently contributed to the schism between symbolic AI, which started out to address higher levels of cognition, and connectionist AI, which concentrated on learning, perception, and motor control.

AI has always been the pioneer battalion of computer science, but despite all its engineering successes, it is still far from explaining intelligence. We may have discovered many pieces of the puzzle, but we are still in the early stages of fitting them together.

Nothing is as strongly associated to the Massachusetts Institute of Technology as Artificial Intelligence and the person of Marvin Minsky himself. In the 60 years since Marvin started the field, he has inspired several generations of students and researchers to think about minds. Many of his inventions, and scientific contributions, his deep, yet very accessible books and his lectures were far ahead of their time, and have not lost any of their relevance.

Marvin Minsky's ideas led me, as many others, on my personal scientific quest. It has been an incredible honor to get to know him during the past year, and my thoughts are with his family and his friends.

I believe that today, the need for working on AI is as pressing as ever. Psychology is still unable to formulate and test theories, neuroscientists are entirely focused on nervous systems and not on minds. Artificial Intelligence is our best bet at understanding who we are, and it is time to continue Marvin's work, to recognize and describe the the richness of our minds, and to build machines that think, feel, perceive, learn, imagine and dream.

No, the universe is not a brain.

At Forbes, Ethan Siegel asks if the universe may be alive. This might bring us to the question what it means to be alive. When biologists started their field, they could only define it by extension (e.g. animals, plants and other similarly animated things), but did not yet have a functional definition of what made the living stuff so special, and came up with vague and wrong ideas (like a motive force, a vis vitalis, permeating living tissue). Now, a few hundred years later, biologists have agreed that they study the class of systems that are organized into one or more cells and self-organize and stabilize based on information stored in DNA. By that definition, the universe is quite certainly not alive.

However, Ethan Siegel (and a few others, like Bernardo Kastrup) suspect that the universe might be conscious, i.e. that the structure given by its stars, galaxies and galaxy clusters might lend itself to a giant information processing architecture.

Arguably, the field of cognitive science is still comparable to early biology when it comes to defining its object of study: researchers somewhat agree that higher mammals, birds and octopi have minds, cognition, a degree of intelligence and awareness, but we do not have a universally accepted functional definition of these properties. Fortunately, cognitive scientists have discarded the vis vitalis equivalent of the mind: the soul, and most of them will agree that minds are motivated information processing systems that make sense of their environment. In a biological organism, this information processing is facilitated by the exchange of signals between different types of neurons and possibly involving glia cells, by means of electrical impulses and chemicals that either act on large portions of the nervous system, or locally at the interface between individual neurons.

It is not clear what environment our universe should make sense of, but contemporary physics tells us something about the limits of its information processing.

Both Siegel and Kastrup (and Clifford Pickover, and oh well, you know who you are) like to illustrate their arguments with the following image:

This image sends a clear message: if we squint a little, then a well-chosen cutout of a false colored image of a golgi stained pyramidal neuron will look like a red down feather, and a well-chosen cutout of a differently false colored galaxy cluster also looks like a purple down feather, and therefore it is extremely likely that the universe is a giant brain.

Why I don't think that Quantum Computers will work, ever

I have just made a bet that quantum computers will not turn out to be better than classical computers within the next fifteen years. I would rather want to bet on "ever", but how could I win such a bet? We could also do a lifetime thing: if you die before the first superclassically fast quantum computer is built, I inherit all your stuff, but that might set the wrong incentives for me. So, 15 years it is. Now let me go out on a limb and explain my intuition that quantum computation will turn out to not really be a thing, ever.

Cat: Do you expect me to compute?

Evil quantum computer scientist: No, Mr Cat, I expect you to die, and to not die, in simultaneous superposition.

Four Gods

When I follow discussions between atheists and enlightened catholics, I notice that they often talk past each other, due to entirely different ideas about what is meant by 'God'. After I found God for myself (not a religious one, but an Aristotelian one), I discovered that there are at least four different aspects of the God concept, which involve quite different assumptions. (This is not exhaustive in any way, of course.)

These are the Four Gods:

1. The God of a religious, institutional narrative. This is a (often personalized) entity with distinct properties and duties that are documented in canonical teachings. Typically, this entity holds strong opinions about the morality of individuals, metes out rewards and punishments, and his prescriptions tend to be aligned with certain political and societal goals. 

2. The God of the spiritual experience. This god is the principle of a universe that is intentional, is conscious, and usually partial towards the individual, but reveals itself independently of allegiance to any religious institution. You will often find that this principle is benevolent and loving, and its interests are well-aligned with your values (see Deepak Chopra), but that is not necessarily the case (Philipp K. Dick's god of 'Valis' comes to mind).

3. The principle of transcendental meaning: God is the question that the universe answers. In the weakest sense, this god is the reason why there is something rather than nothing (an ontological duty that hardly conflicts with any expected future results of scientific inquiry). However, it implies a telos, i.e. the universe inherits a purpose. I think this is the god of Thomas of Aquinas, as apparent in his Fourth and Fifth Proofs for the existence of God.

4. The Prime Mover: rather than assuming that physics is entirely self-contained or that the universe is essentially static (and only appears to be moving due to the way we observe it), there must be something that moves things along. This first mover (primum movens) is arguably the god of Aristotle. 

Rethinking Quantum Mechanics and Inverted Spacetime from a Computationalist Perspective

Warning: Speculative physics bullshit by a non-physicist

Tl;dr: If Maldacena and van Raamsdonk are correct, then spacetime might not be real, but weakly emergent. The computer that runs the universe does not index particles within a spacetime matrix, but only maintains a tensor network with quantized properties. The apparence of spacetime is the result of entanglement.

Nature just published a short commentary on a possible quantum theoretical foundation of space time. In short, it suggests that spacetime is not the reason why particles get entangled with each other (i.e. they got close enough to influence each other), but that it is the other way around: spacetime is the emergent result of the entanglement of particles. The case is not strong yet, but it would have huge implications for a grand unified theory, and possibly also for the relationship between the quantum world and computation.

Why Twitter was right to replace stars with hearts, and why you hate it

Last Tuesday, Twitter replaced its appreciation expressor button, pictured as a star, with a heart. Instead of "favs", twitter users will now send "likes" to each other when they want to express that they feel positively disposed towards a 140 character string or its author. Twitter did not change any functionality, but what may look like a tiny typographic change made my timeline extremely angry.

By now (Wednesday), I have seen twitter petitions with thousand of signatures, polls, threats of quitting the social network, and (within the confines of 140 characters) well argued calls for reverting the change. Twitter is "reminding us that our public spaces are privately owned", it "infantilizes communication", it "sacrifices existing users to get new users into the platform", it removes my ability to express appreciation without implying emotional alignment. How could Twitter do such a stupid thing?

In Defense of Cryonics

The current issue of Technology Review contains Michael Hendricks' scathing condemnation of the proposal of cryonics, i.e. the idea of freezing your body or at least your brain as soon and as rapidly as possible after death, with the goal of being revived in a distant future where technology has progressed to the point where it is possible to do so.

Due to the difficulties of recreating decayed and destroyed tissue, this resurrection might well not be in the flesh, but could involve scanning and recreating the configuration of the brain as closely as possible, using a computational simulation. It is this particular vision that Hendricks argues against.
Hendricks is an expert on nematodes, specifically the roundworm Caenorhabditis elegans, which tends to live in soil and feed on decaying organic matter when not spending time in the lab. I can see why Caenorhabditis dislikes the prospect of his food ending up in  Alcor's freezer instead of the soil, but the core of Hendricks' arguments is not as compelling to me.

Hendricks makes five especially salient points: