The Fabric of Reality

The Fabric of Reality, a 1997 book by David Deutsch, is full of great ideas, most of them surprising and intriguing. The main argument is that explanations are the centerpiece of science and that four theories play an essential role in our understanding of the world: quantum theory, the theory of evolution, the theory of computation and epistemology (the theory of knowledge).

You may raise a number of questions about these particular choices, such as why is the theory of relativity not there or why is the theory of evolution simply not a result of other theories in physics or even what makes epistemology to special. You will have to read the book to find out but the short answer is that not everything is physics and that theories at many levels are required to explain the world. Still, in physics, the most fundamental idea is quantum theory and it has profound impacts on our understanding of the universe. Perhaps the most significant impact comes from the fact that (according to Deutsch) what we know about quantum theory implies that we live in a multiverse. Each time a quantum phenomenon can conduct to more than one observable result, the universe splits into as many universes as the number of possible results, universes that exist simultaneously in the multiverse.

Although the scientific establishment views the multiverse theory with reservation, to say the least, to Deutsch, the multiverse is not just a theory, but the only possible explanation for what we know about quantum physics (he dismisses the Copenhagen interpretation as nonsense). Armed with these four theories, and the resulting conclusion that we live in a multiverse, Deutsch goes on to address thought-provoking questions, such as:

  • Is life a small thing at the scale of the universe or, on the contrary, is the most important thing on it?
  • Can we have free will, in a deterministic universe? And in the multiverse?
  • Do computers strictly more powerful than Turing machines exist, and how do they work?
  • Can mathematical proofs provide us with absolute certainties about specific mathematical statements?
  • Is time travel possible, at least in principle, either in the physical world or in a virtual reality simulator?
  • Will we (or our descendants, or some other species) eventually become gods, when we reach the Omega point?

The idea of the multiverse is required to answer most, if not all, of these questions. Deutsch is certainly not a parsimonious person when he uses universes to answer questions and to solve problems. The multiverse allows you to have free will, solves the paradoxes of time travel and makes quantum computers possible, among many other things. One example of the generous use of universes made by Deutsch is the following sentence:

When a quantum factorization engine is factorizing a 250-digit number, the number of interfering universes will be of the order of 10 to the 500. This staggeringly large number is the reason why Shor’s algorithm makes factorization tractable. I said that the algorithm requires only a few thousand arithmetic operations. I meant, of course, a few thousand operations in each universe that contributes to the answer. All those computations are performed in parallel, in different universes, and share their results through interference.

The fact that Deutsch’s arguments depend so heavily on the multiverse idea makes this book much more about the multiverse than about the other topics he addresses. After all, if the multiverse theory is wrong, many of Deutsch’s explanations collapse, interesting as they may be.

Still, the book is full of great ideas, makes for some interesting reading, and presents many interesting concepts, some of them further developed in other books by Deutsch, such as The Beginning of Infinity.


Enlightenment Now: The case for reason, science, humanism and progress

Steven Pinker’s latest book, Enlightenment Now, deserves high praise and careful attention, in a world where reason and science are being increasingly threatened. Bill Gates called it “My new favorite book of all time“, which may be somewhat of an exaggeration. Still, the book is, definitely, a must read, and should figure in the top 10 of any reader that believes that science plays an important role in the development of humanity.

Pinker’s main point is that the values of the Enlightenment, which he lists as reason, science, humanism, and progress have not only enabled humanity to evolve immensely since they were adopted, somewhere in the 18th century, but are also our best hope for the future. He argues that these values have not only improved our lives immensely, in the last two and a half centuries, but will also lead us to vastly improved lives in the future. “Dare to understand“, the cry for reason made by David Deutsch in his The Beginning of Infinity, is the key argument made by Pinker in this book. The critical use of reason leads to understanding and understanding leads to progress, unlike the beliefs in myths, religions, miracles, and signs from God(s).  Pinker’s demolition of all the values not based on the critical use of reason is complete and utterly convincing. Do not read this book if, at some level, you believe in things that cannot be explained by reason.

To be fair, a large part of the book is dedicated to showing that progress has, indeed, been remarkable, since the 18th century, when reason and science took hold and replaced myths and religions as the major references for the development of nations and societies. No less than 17 chapters are dedicated to describing the many ways humanity has progressed in the last two and a half centuries, in fields as diverse as health, democracy, wealth, peace and, yes, even sustainability.  Pinker may come up as an incorrigible optimist, describing a world so much better than that which existed in the past, so at odds with the most popular current views that everything is going to the dogs. However, the evidence he presents is compelling, well documented, and discussed at length. Counter-arguments against the idea that progress is true and unstoppable are analyzed in depth and disposed of with style and elegance.

But the book is not only about past progress. In fact, it is mostly about the importance of viewing the Enlightenment values as the only ones that will safeguard a future for humanity. If we want a future, we need to preserve them, in a world where fake news, false science, and radical politics are endangering progress, democracy, and human rights.

It is comforting to find a book that so powerfully defends science, reason, and humanistic values against the claims that only a return to the ways of the past will save humanity of certain doom. Definitely, a must read if you believe in, and care for, Humanity.

Our Final Invention: Artificial Intelligence and the end of the human era

In what regards the state of the art in Artificial Intelligence, and the speed that it will develop, James Barrat is extremely optimistic. The author of Our Final Invention is fully convinced that existing systems are much more advanced than we give them credit for, and also that  AI researchers will create Artificial General Intelligence (AGI) much sooner than we expect.

In what regards the consequences of AGI, however, Barrat is uncompromisingly pessimistic. He believes, and argues at length, that AGI will bring with it the demise of the human race and that we should stop messing with advanced AI altogether.

I found the arguments presented for both positions rather unconvincing. His argument for the most likely development of AGI in the next decade or so is based on rather high-level considerations and conversations with a number of scientists, researchers, and entrepreneurs from the field. Needless to say, they were picked from the ones most connected with his ideas. As for the arguments that AGI will be not only dangerous but, ultimately, fatal for humanity, they are borrowed, with minor changes, from the standard superintelligence (Bostrom) and intelligence explosion (I. J. Good) ideas.

From Watson’s performance in Jeopardy and from the ANN’s small victories in the perception fields, Barrat concludes, without any additional considerations, that AGI is around the corner and that it will be very, very, dangerous. The book was written before the recent successes achieved by DeepMind and others, which leads me to believe that, if written now, his conclusions would be even more drastic.

Even though there is relatively new material here, a few stories and descriptions are interesting. Barrat makes extensive use of his conversations with the likes of Omohundro, Yudkwosky, Vassar, and Kurzweil and some stories are very entertaining, even though they look a bit like science fiction. Altogether, the book makes for some interesting, if somewhat unconvincing, reading.

Virtually Human: the promise of digital immortality

Martine Rothblatt’s latest book, Virtually Human, the promise – and the peril – of digital immortality, recommended by none less than the likes of Craig Venter and Ray Kurzweil, is based on an interesting premise, which looks quite reasonable in principle.

Each one of us leaves behind such a large digital trace that it could be used, at least in principle, to teach a machine to behave like the person that generated the trace. In fact, if you put together all the pictures, videos, emails and messages that you generate in a lifetime, together with additional information like GPS coordinates, phone conversations, and social network info, there should be enough information for the right software to learn to behave just like you.

Rothblatt imagines that all this information will be stored in what she calls a mindfile and that such a mindfile could be used by software (mindware) to create mindclones, software systems that would think, behave and act like the original human that was used to create the mindfile. Other systems, similar to these, but not based on a copy of a human original, are called bemans, and raise similar questions. Would such systems have rights and responsibilities, just like humans? Rothblatt argues forcefully that society will have to recognize them as persons, sooner or later. Otherwise, we would assist to a return to situations that modern societies have already abandoned, like slavery, and other practices that disrespect basic human rights (in this case, mindclone and beman’s rights).

Most of the book is dedicated to the analysis of the social, ethical, and economic consequences of an environment where humans live with mindclones and bemans. This analysis is entertaining and comprehensive, ranging from subjects as diverse as the economy, human relations, families, psychology, and even religion.  If one assumes the technology to create mindclones will happen, thinking about the consequences of such a technology is interesting and entertaining.

However, the book falls short in that it does not provide any convincing evidence that the technology will come to exist, in any form similar to the one that is assumed so easily by the author. We do not know how to create mindware that could interpret a mindfile and use it to create a conscious, sentient, self-aware system that is indistinguishable, in its behavior, from the original. Nor are we likely to find out soon how such a mindware could be designed. And yet, Rothblatt seems to think that such a technology is just around the corner, maybe just a few decades away. All in all, it sounds more like (poor) science fiction than the shape of things to come.

The Beginning of Infinity

David Deutsch‘s newest book, The Beginning of Infinity is a tour de force argument for the power of science to transform the world. Deutsch’s main point is that human intelligence, once it reached the point where it started to be used to construct predictive explanations about the behavior of nature, became universal. Here, “universal” means that is can be used to understand any phenomenon and that this understanding leads to the creation of new technologies, which will be used to spread human intelligence throughout the known universe.

The Beginning of Infinity is not just one more book about science and how science is transforming our world. It is an all-encompassing analysis of the way human intelligence and human societies can develop or stagnate, by adopting or refusing to adopt the stance of looking for understandable explanations. Deutsch calls “static” those societies that refuse to look for new, non-supernatural explanations and “dynamic” those that are constantly looking for new explanations, based on objective and checkable evidence. Dynamic societies, he argues, develop and propagate rational memes, while static societies hold on to non-rational memes.

In the process, Deutsch talks authoritatively about evolution, the universality of computation, quantum mechanics, the multiverse and the paradoxes of infinity. They are not disparate subjects since they all become part of one single story on how humanity managed to understand and control the physical world.

Deutsch is at his best when arguing that science and technology are not only positive forces but that they are the only way to ensure the survival of Humanity in the long run. He argues, convincingly, against the myth of Gaia, the idea that the planet is a living being providing us with a generous and forgiving environment as well as against the related, almost universal, concern that technological developments are destroying the planet. This is nonsense, he argues. The future survival of Humanity and the hope of spreading human intelligence throughout the Cosmos reside entirely in our ability to control nature and to bend it to our will. Otherwise, we will follow the path of the many species that became extinct, for not being able to control the natural or unnatural phenomena that led to their extinction.

Definitely, the book to read if you care about the Future of Humanity.


Crystal Nights

Exactly 80 years ago, Kristallnacht (the night of the crystals) took place in Germany, in the night from the 9th to the 10th of November. Jews were persecuted and killed, and their property was destroyed, in an event that is an important marker in the rise of the anti-semitism movement that characterized Nazi Germany. The name comes from the many windows of Jewish-owned stores broken during that night.

Greg Egan, one of my favorite science fiction writers, wrote a short story inspired in that same night, entitled Crystal Nights. This (very) short story is publicly available (you can find it here ) and is definitely worth a reading. I will not spoil the ending here, but it has to do with computers and singularities. The story was also included in a book that features other short stories by Greg Egan.

If you like this story, maybe you should check other books by Egan, such as Permutation City, Diaspora or Axiomatic (another collection of short stories).

Hello World: how to be human in the age of the machine

Computers, algorithms, and data are controlling our lives, powering our economy and changing our world. Unlike a few decades ago, the larger companies on the planet deal mostly with data manipulation, processed by powerful algorithms that help us decide what we buy, which songs we like, where we go and how we get there. More and more, we are becoming unwitty slaves to these algorithms, which are with us all the time, running on cell phones, computers, servers, and smart devices. And yet, few people understand what an algorithm is, what artificial intelligence really means, or what machine learning can do.

Hannah Fry’s new book opens a window on this world of algorithms and on the ways they are changing our lives and societies. Despite its name, this book is not about programming nor is it about programs. The book is about algorithms, and the ways they are being used in the most diverse areas, to process data and obtain results that are of economic or societal value.

While leading us through the many different areas where algorithms are used these days, Fry passes on her own views about the benefits they bring but also about the threats they carry with them. The book starts by addressing the issue of whether we, humans, are handling too much power to algorithms and machines. This has not to do with the fear of intelligent machines taking over the world, the fear that a superintelligence will rule us against our will. On the contrary, the worry is that algorithms that are effective but not that intelligent will be trusted to take decisions on our behalf; that our privacy is being endangered by our willingness to provide personal data to companies and agencies; that sub-optimal algorithms working on insufficient data may bring upon us serious unintended consequences.

As Fry describes, trusting algorithms to run our lives is made all the more dangerous by the fact that each one of us is handing over huge amounts of personal data to big companies and government agencies, which can use them to infer information that many of us would rather keep private. Even data that we deem most innocent, like what we shop at the grocery, is valuable and can be used to extract valuable and, sometimes, surprising information. You will learn, for instance, that pregnant women, on their second trimester, are more likely to buy moisturizer, effectively signaling the data analysts at the stores that a baby is due in a few months. The book is filled with interesting, sometimes fascinating, descriptions of cases like these, where specific characteristics on the data can be used, by algorithms, to infer valuable information.

Several chapters are dedicated to a number of different areas where data processing and algorithmic analysis have been extensively applied. Fry describes how algorithms are currently being used in areas as diverse as justice, transportation, medicine, and crime prevention. She explains and analyses how algorithms can be used to drive cars, influence elections, diagnose cancers, make decisions on parole cases and rulings in courts, guess where crimes will be committed, recognize criminals in surveillance videos, predict the risk of Alzheimer from early age linguistic ability, and many other important and realistic applications of data analysis. Most of these algorithms use what we now call artificial intelligence and machine learning but it is clear that, to the author, these techniques are just toolboxes for algorithm designers. The many examples included in these chapters are, in themselves, very interesting and, in some cases, riveting. However, what is most important is the way the author uses these examples to make what I feel is the central point of the book: using an algorithm implies a tradeoff and every application brings with it benefits and risks, which have to be weighted. If we use face recognition algorithms to spot criminals, we have to accept the risk of an algorithm sending an innocent person to jail. If we police more the locations where crimes are more likely to take place, people on those areas may feel they are treated unfairly. If we use social data to target sale campaigns, then it can also be used to market political candidates and manipulate elections. The list of tradeoffs goes on and on and every one of them is complex.

As every engineer knows, there is no such thing as 100% reliability or 100% precision. Every system that is designed to perform a specific task will have a given probability of failing at it, however small. All algorithms that aim at identifying some specific targets will make mistakes. They will falsely classify some non-target cases as targets (false positives) and will miss some real targets (false negatives). An autonomous car may be safer than a normal car with a human driver but will, in some rare cases, cause accidents that would not have happened, otherwise. How many spurious accidents are we willing to tolerate, in order to make roads safer to everyone? These are difficult questions and this book does a good job at reminding us that technology will not make those choices for us. It is our responsibility to make sure that we, as a society, assess and evaluate clearly the benefits and risks of each and every application of algorithms, in order to make the overall result be positive for the world.

The final chapter addresses a different and subtler point, which can be framed in the same terms that Ada Lovelace put it, more than 150 years ago: can computers originate new things, can they be truly creative? Fry does not try to find a final answer to this conundrum, but she provides interesting data on the subject, for the reader to decide by him- or herself. By analyzing the patterns of the music written by a composer, algorithms can create new pieces that, in many cases, will fool the majority of the people and even many experts. Does this mean that computers can produce novel art? And, if so, is it good art? The answer is made the more difficult by the fact that there are no objective measures for the quality of works of art. Many experiences, some of them described in this chapter, show clearly that the beauty is, in many cases, in the eye of the beholder. Computer produced art is good enough to be treated like the real thing, at least when the origin of the work is not known. But many people will argue that copying someone else’s style is not really creating art. Others will disagree. Nonetheless, this final chapter provides an interesting introduction to the problem of computer creativity and the interested reader can pick on some of the leads provided by the book to investigate the issue further.

Overall, Hello World is definitely worth reading, for those interested in the ways computers and algorithms are changing our lives.

Note: this is an edited version of the full review that appeared in Nature Electronics.