Extraterrestrial: The First Sign of Alien Life?

Avi Loeb is not exactly someone who one may call an outsider to the scientific community. As a reputed scholar and the longest serving chair of Harvard’s Department of Astronomy, he is a well-known and reputed physicist, with many years of experience in astrophysics and cosmology. It is therefore somewhat surprising that in this book he strongly supports an hypothesis that is anything but widely accepted in the scientific community: ʻOumuamua, the first interstellar object ever detected in our solar system may be an artifact created by an alien civilization.

We are not talking here about alien conspiracies, UFOs or little green men from Mars. Loeb’s idea, admirably explained, is that there are enough strange things about ʻOumuamua to raise the real possibility that it is not simply a strange rock and that it may be an artificial construct, maybe a lightsail or a beacon.

There are, indeed, several strange things about this object, discovered by a telescope in Hawaii, in October 2017. It was the first object ever discovered near the Sun that did not orbit our star; its luminosity changed radically, by a factor of about 10; it is very bright for its size; and, perhaps more strangely, it exhibited non‑gravitational acceleration as its orbit did not exactly match the orbit of a normal rock with no external forces applied other than the gravity of the Sun.

None of these abnormalities, per se, would be enough to raise eyebrows. But, all combined, they do indeed make for a strange object. And Loeb’s point is, exactly, that the possibility that ‘Oumuamua is an artifact of alien origin should be taken seriously by the scientific community. And yet, he argues, anything that has to do with extraterrestrial life is not considered serious science, leading to a negative bias and to a lack of investment in what should be one of the most important scientific questions: are we alone in the Universe? As such, SETI, the Search for Extra-Terrestrial Life, does not get the recognition and the funding it deserves. Paradoxically, other fields whose theories may never be confirmed by experiment nor have any real impact on us, such as multiverse based explanations of quantum mechanics or string theory, are considered serious fields, attract much more funding, and are more favorably viewed by young researchers.

The book makes for very interesting reading, both for the author’s positions about ‘Oumuamua itself and for his opinions about today’s scientific establishment.

Possible minds

John Brockman’s project of bringing together 25 pioneers in Artificial Intelligence to discuss the promises and perils of the field makes for some interesting reading. This collection of short essays lets you peer inside the minds of such luminaries as Judea Pearl, Stuart Russell, Daniel Dennett, Frank Wilczek, Max Tegmark, Steven Pinter or David Deutsch, to name only a few. The fact that each one of them contributed with an essay that is only a dozen pages long does not hinder the transmission of the messages and ideas they support. On the contrary, it is nice to read about Pearl’s ideas about causality or Tegmark’s thoughts on the future of intelligence in a short essay. Although the essays do not replace longer and more elaborate texts, they certainly give the reader the gist of the central arguments that, in many cases, made the authors well-known. Although the organization of the essay varies from author to author, all contributions are relevant and entertaining, whether they come from lesser-known artists or from famous scientists such as George Church, Seth Loyd, or Rodney Brooks.

The texts in this book did not appear out of thin air. In fact, the invited contributors were given the same starting point: Norbert Wiener’s influential book “The Human Use of Human Beings”, a prescient text authored more than 70 years ago by one of the most influential researchers in the field that, ultimately, originally coined as cybernetics ultimately led to digital computers and Artificial Intelligence. First published in 1950, Wiener’s book serves as the starting point for 25 interesting takes on the future of computation, artificial intelligence, and humanity. Whether you believe that the future of humanity will be digital or are concerned that we are losing our humanity, there will be something in this book for you.

Is the Universe a mathematical structure?

In his latest book, Our Mathematical Universe: My Quest for the Ultimate Nature of Reality, Max Tegmark tries to answer what is maybe the most fundamental question in science and philosophy: what is the nature of reality?

Our understanding of reality has certainly undergone deep change in the last few centuries. From Galileo and Newton, to Maxwell, Einstein, Bohr and Heisenberg, Physics has evolved by leaps and bounds, as well as our understanding of the place of humans in the Universe. And yet, in some respects, we know little more than the ancient Greeks. Is the visible Universe all that exists? Could other universes, with different laws of physics, exist? Does the universe split into several universes every time a quantum observation takes place? Why is mathematics such a good model for physics (an old question) and could there exist other universes which obey different mathematical structures? These questions are not arbitrary ones, as their answers take us into the four levels of the multiverse proposed by Tegmark.

As you dive into it, the book takes us into an ever-expanding model of reality. Tegmark defines four level of multiverses: the first one consisting of all the (possibly infinite) spacetime of which we see only a ball with a radius of 14 billion light-years, since the rest is too far for light to have reached us; the second one which possibly holds other parts of spacetime which obey different laws of physics; a third one, implied by the many-worlds interpretation of quantum physics; and a fourth one, where other mathematical structures, different from the spacetime we know and love, define the rules of the game.

It is certainly a lot to take in, in a book that has less than 400 pages, and the reader may feel dizzy at times. But, in the process, Tegmark does his best at explaining what inflation is and why it plays such an important role in cosmology, how the laws of quantum physics can be viewed simply as an equation (the Schrödinger equation) describing the evolution of a point in Hilbert space, doing away with all the difficult-to-explain consequences of the Copenhagen interpretation, the difficulties caused by the measure problem, why is the space so flat, and many, many other fascinating topics in modern physics.

Since the main point of the book is to help is understand our place in this not only enormous Universe but unthinkably enormous multiverse, he brings us back to Earth (literally) with a few disturbing questions, such as:

  • What is the role of intelligence and consciousness in this humongous multiverse?
  • Why is this Universe we see amenable to life, in some places, and why have we been so lucky to be born exactly here?
  • Shall one view oneself as a random sample of an intelligent being existing in the universe (the SSA, or Self-Sampling Assumption proposed by Bostrom in his book Anthropic Bias)
  • If the SSA is valid, does it imply the Doomsday Argument, that it is very unlikely that humans will last for a long time because such a fact that would make it highly unlikely that I would have been born so soon?

All in all, a fascinating read, if at times is reads more like sci-fi than science!

Chinese translation of The Digital Mind

The Chinese translation of my book, The Digital Mind, is now available. For those who want to dust off their (simplified) Chinese, it can be found in the usual physical and online bookstores, including Amazon and Books.com. Regrettably, I cannot directly assess the quality of the translation, you will have to decide for yourself. Or maybe you’d rather go for the more mundane English version, published by MIT Press, or the Portuguese one, published by IST Press.

You’re not the customer, you’re the product!

The attention that each one of us pays to an item and the time we spend on a site, article, or application is the most valuable commodity in the world, as witnessed by the fact that the companies that sell it, wholesale, are the largest in the world. Attracting and selling our attention is, indeed, the business of Google and Facebook but also, to a larger extent, of Amazon, Apple, Microsoft, Tencent, or Alibaba. We may believe we are the customers of these companies but, in fact, many of the services provided serve, only, to attract our attention and sell it to the highest bidder, in the form of publicity of personal information. In the words of Richard Serra and Carlota Fay Schoolman, later reused by a number of people including Tom Johnson, if you are not paying “You’re not the customer; you’re the product.

Attracting and selling attention is an old business, well described in Tim Wu’s book The Attention Merchants. First created by newspapers, then by radios and television, the market of attention came to maturity with the Internet. Although newspapers, radio programs, and television shows have all been designed to attract our attention and use it to sell publicity, none of them had the potential of the Internet, which can attract and retain our attention by tailoring the contents to each and everyone’s content.

The problem is that, with excessive customization, comes a significant and very prevalent problem. As sites, social networks, and content providers fight to attract our attention, they show us exactly the things we want to see, and not the things as they are. Each person lives, nowadays, in a reality that is different from anyone else’s reality. The creation of a separate and different reality, for each person, has a number of negative side effects, that include the creation of paranoia-inducing rabbit holes, the radicalization of opinions, the inability to establish democratic dialogue, and the diffiulty to distinguish reality from fabricated fiction.

Wu’s book addresses, in no light terms, this issue, but the Netflix documentary The Social Dilemma makes an even stronger point that customized content, as shown to us by social networks and other content providers is unraveling society and creating a host of new and serious problems. Social networks are even more worrying than other content providers because they create pressure in children and young adults to conform to a reality that is fabricated and presented to them in order to retain (and resell) their attention.

Novacene: the future of humanity is digital?

As it says on the cover of the book, James Lovelock may well be “the great scientific visionary of our age“. He is probably best known for the Gaia Hypothesis, but he made several other major contributions. While working for NASA, he was the first to propose looking for chemical biomarkers in the atmosphere of other planets as a sign of extraterrestrial life, a method that has been extensively used and led to a number of interesting results, some of them very recent. He has argued for climate engineering methods, to fight global warming, and a strong supporter of nuclear energy, by far the safest and less polluting form of energy currently available.

Lovelock has been an outspoken environmentalist, a strong voice against global warming, and the creator of the Gaia Hypothesis, the idea that all organisms on Earth are part of a synergistic and self-regulating system that seeks to maintain the conditions for life on Earth. The ideas he puts forward in this book are, therefore, surprising. To him, we are leaving the Anthropocene (a geological epoch, characterized by the profound effect of men on the Earth environment, still not recognized as a separate epoch by mainstream science) and entering the Novacene, an epoch where digital intelligence will become the most important form of life on Earth and near space.

Although it may seem like a position inconsistent with his previous arguments about the nature of life on Earth, I find the argument for the Novacene era convincing and coherent. Again, Lovelock appears as a visionary, extrapolating to its ultimate conclusion the trend of technological development that started with the industrial revolution.

As he says, “The intelligence that launches the age that follows the Anthropocene will not be human; it will be something wholly different from anything we can now conceive.”

To me, his argument that artificial intelligence, digital intelligence, will be our future, our offspring, is convincing. It will be as different from us as we are from the first animals that appeared hundreds of millions ago, which were also very different from the cells that started life on Earth. Four billion years after the first lifeforms appeared on Earth, life will finally create a new physical support, that does not depend on DNA, water, or an Earth-like environment and is adequate for space.

The Book of Why

Correlation is not causation is a mantra that you may have heard many times, calling attention to the fact that no matter how strong the relations one may find between variables, they are not conclusive evidence for the existence of a cause and effect relationship. In fact, most modern AI and Machine Learning techniques look for relations between variables to infer useful classifiers, regressors, and decision mechanisms. Statistical studies, with either big or small data, have also generally abstained from explicitly inferring causality between phenomena, except when randomized control trials are used, virtually the unique case where causality can be inferred with little or no risk of confounding.

In The Book of Why, Judea Pearl, in collaboration with Dana Mackenzie, ups the ante and argues not only that one should not stay away from reasoning about causes and effects, but also that the decades-old practice of avoiding causal reasoning has been one of the reasons for our limited success in many fields, including Artificial Intelligence.

Pearl’s main point is that causal reasoning is not only essential for higher-level intelligence but is also the natural way we, humans, think about the world. Pearl, a world-renowned researcher for his work in probabilistic reasoning, has made many contributions to AI and statistics, including the well known Bayesian networks, an approach that exposes regularities in joint probability distributions. Still, he thinks that all those contributions pale in comparison with the revolution he speared on the effective use of causal reasoning in statistics.

Pearl argues that statistical-based AI systems are restricted to finding associations between variables, stuck in what he calls rung 1 of the Ladder of Causation: Association. Seeing associations leads to a very superficial understanding of the world since it restricts the actor to the observation of variables and the analysis of relations between them. In rung 2 of the Ladder, Intervention, actors can intervene and change the world, which leads to an understanding of cause and effect. In rung 3, Counterfactuals, actors can imagine different worlds, namely what would have happened if the actor did this instead of that.

This may seem a bit abstract, but that is where the book becomes a very pleasant surprise. Although it is a book written for the general public, the authors go deeply into the questions, getting to the point where they explain the do-calculus, a methodology Pearl and his students developed to calculate, under a set of dependence/independence assumptions, what would happen if a specific variable is changed in a possibly complex network of interconnected variables. In fact, graphic representations of these networks, causal diagrams, are at the root of the methods presented and are extensively used in the book to illustrate many challenges, problems, and paradoxes.

In fact, the chapter on paradoxes is particularly entertaining, covering the Monty Hall, Berkson, and Simpson’s paradoxes, all of them quite puzzling. My favorite instance of Simpson’s paradox is the Berkeley admissions puzzle, the subject of a famous 1975 Science article. The paradox comes from the fact that, at the time, Berkeley admitted 44% of male candidates to graduate studies, but only 35% of female applicants. However, each particular department (departments decide the admissions in Berkeley, as in many other places) made decisions that were more favorable to women than men. As it turns out, this strange state of affairs has a perfectly reasonable explanation, but you will have to read the book to find out.

The book contains many fascinating stories and includes a surprising amount of personal accounts, making for a very entertaining and instructive reading.

Note: the ladder of causation figure is from the book itself.

Instantiation, another great collection of Greg Egan’s short stories

Greg Egan is a master of short-story telling. His Axiomatic collection of short stories is one of my favorites. This new collection of short stories keeps Egan’s knack for communicating deep concepts using few words and dives deeper into the concepts of virtual reality and the impacts of technology in society.

The first story, The discrete charm of the Turing machine, could hardly be more relevant these days, when the discussions on the economic impacts of Artificial Intelligence are taking place everywhere. But the main conducting line of the book is the series of stories where sentient humans who are, in fact, characters in virtual reality games, plot to break free of their slave condition. To find out whether they succeed or not, you will have to read to book yourself!

PS: As a joke, I leave here a meme of unknown origin

Human Compatible: AI and the Problem of Control

Stuart Russell, one of the better-known researchers in Artificial Intelligence, author of the best selling textbook Artificial Intelligence, A Modern Approach addresses, in his most recent book, what is probably one of the most interesting open questions in science and technology: can we control the artificially intelligent systems that will be created in the decades to come?

In Human Compatible: AI and the Problem of Control Russell formulates and answers the following, very important question: what are the consequences if we succeed in creating a truly intelligent machine?

The question brings, with it, many other questions, of course. Will intelligent machines be dangerous to humanity? Will they take over the world? Could we control machines that are more intelligent than ourselves? Many writers and scientists, like Nick Bostrom, Stephen Hawking, Elon Musk, Sam Harris, and Max Tegmark have raised these questions, several of them claiming that superintelligent machines could be around the corner and become extremely dangerous to the humanity.

However, most AI researchers have dismissed these questions as irrelevant, concentrated as they are in the development of specific techniques and well aware that Artificial General Intelligence is far away, if it is at all achievable.  Andrew Ng, another famous AI researcher, said that worrying about superintelligent machines is like worrying about the overpopulation. of Mars.

There could be a race of killer robots in the far future, but I don’t work on not turning AI evil today for the same reason I don’t worry about the problem of overpopulation on the planet Mars

Another famous Machine Learning researcher, Pedro Domingos, in his bestselling book, The Master Algorithm, about Machine Learning, the driving force behind modern AI, also ignores these issues, concentrating on concrete technologies and applications. In fact, he says often that he is more worried about dumb machines than about superintelligent machines.

Stuart Russell’s book is different, making the point that we may, indeed, lose control of such systems, even though he does not believe they could harm us by malice or with intention. In fact, Russell is quite dismissive of the possibility that machines could one day become truly intelligent and conscious, a position I find, personally, very brave, 70 years after Alan Turing saying exactly the opposite.

Yet, Russell believes we may be in trouble if sufficiently intelligent and powerful machines have objectives that are not well aligned with the real objectives of their designers. His point is that a poorly conceived AI system, which aims at optimizing some function that was badly specified can lead to bad results and even tragedy if such a system controls critical facilities. One well-known example is Bostrom’s paperclip problem, where an AI system designed to maximize the production of paperclips turns the whole planet into a paperclip production factory, eliminating humanity in the process. As in the cases that Russell fears, the problem comes not from a machine which wants to kill all humans, but from a machine that was designed with the wrong objectives in mind and does not stop before achieving them.

To avoid that risk os misalignment between human and machine objectives, Russell proposes designing provably beneficial AI systems, based on three principles that can be summarized as:

  • Aim to maximize the realization of human preferences
  • Assume uncertainty about these preferences
  • Learn these preferences from human behavior

Although I am not fully aligned with Russell in all the positions he defends in this book, it makes for interesting reading, coming from someone who is a knowledgeable AI researcher and cares about the problems of alignment and control of AI systems.

The Origin of Consciousness in the Breakdown of the Bicameral Mind

The origin of consciousness in the breakdown of the bicameral mind, a 1976 book by Julian Jaynes, is probably one of the most intriguing and contentious works in the already unusually controversial field of consciousness studies. This book proposed bicameralism, the hypothesis that the human mind once operated in a state in which cognitive functions were divided between one half of the brain, which appears to be speaking, and another half which listens and follows instructions. Julian Jaynes’ central claim is that consciousness in humans, in the form that is familiar to us today, is a relatively recent phenomenon, whose development followed the invention of writing, the evolution of complex societies and the collapse of bicameralism. According to Jaynes, in the bicameral eras, humans attributed the origin of the inner voices (which we presumably all hear) not to themselves, but to gods. Human behavior was, therefore, not conscious but automatic. Actions followed from strict obedience to these inner voices, which represented orders from a personal god, themselves conditioned by social and cultural norms.

In Jaynes view, consciousness is strongly connected with human language (an assertion hard to refute but possibly an insufficiently general description) and results, in large part, from our ability to introspect, and to hold conversations and dialogues with ourselves. The change in human’s perception of these voices, a process which, according to Jaynes, took place over a time span that lasted only a couple of millennia, during the Babylonian, Assyrian, Greek and Egyptian civilizations (the ones he studied) led to the creation of consciousness as we know it today. This implies that human consciousness, as it exists today, is a brand new phenomenon, in the evolutionary timescale.

Taken at face value, this theory goes totally against the very ingrained belief that humans have been fully conscious for hundreds of thousands or even millions of years, if we consider other species of hominids and other primates. It is certainly strange to think that consciousness, as we know it, is a phenomenon with only a few millennia.

And yet, Jaynes’ arguments are everything but naive. They are, in fact, very sophisticated and based on extensive analyses of historical evidence. The problem with the theory is not that it is simplistic or that there is a lack of presented evidence. The problem I have with this theory is that the evidence presented comes mostly from a very subjective and argumentative analysis of historical artifacts (books, texts, vases, ruins), which are interpreted, in a very intelligent way, to support Jaynes’ main points.

To give an example, which plays an important role in the argument, let’s consider the Iliad. In this text, which predates, according to Jaynes, conscious behavior, and has its origins in bicameral times, all human actions derive, directly, from the clear and audible instructions received from gods. In the Iliad, there is no space for reflection, autonomy, cogitations, hesitations or doubts. Heroes and plain humans act on the voices of gods, and that’s it. The Odyssey and posterior texts are progressively more elaborate on human thought and motivation and (according to Jaynes) the works of Solon are the first that can be viewed as modern, consistent with our current views of human will and human consciousness. Most significant of all, to Jaynes, is the Bible, in particular the Old Testament, which he sees as the ultimate record of the progressive evolution of men from bicameralism to subjective, conscious, behavior.  Analysis of these texts and of other evidence of the evolution of consciousness in Mesopotamia, Assyria, Greece, and Egypt, are exhaustively presented, and should not be taken lightly. At the least, Jaynes may have a point in that consciousness, today, is not the same thing as consciousness, five millennia ago. This may well be true, and it is hard for us to understand human thought from that time.

An yet, I remained unconvinced of Jaynes’ main point. True, the interpretation he makes of the historical evidence is from someone who has studied the materials deeply and I am certainly unable to counter-argue with someone who is so familiar with the topics. But, to me, the many facts (thousands, probably) that he brings to bear on his argument can all be the result of many other factors. Maybe the writers of the Iliad wanted to use god’s voices for stylistic effect, maybe the empty throne of the Assyrian king Tukulti-Ninurta depicted in a famous scene is not due to the disappearance and silence of the gods (as he argues) but to some other reasons. Jaynes proposes many interesting and ingenious interpretations of historical data, but in the end I was not convinced that these interpretations are sufficient to support his main thesis.

Despite missing his main objective, however, the book makes for a great read, presenting an interpretation of ancient history that is gripping and enlightening, if not fully convincing.