In our quest for understanding, the scientific enterprise is far from a smooth endeavor. Over the centuries, scientists and philosophers alike have sought to describe and make sense of the world around us. So great is science’s explanatory power that some believe it holds the key to all the answers we’ve been seeking for so long, even if we do not possess the tools and technology to reach them yet. Yet, while science has done much to describe the world around us and improve our daily lives, there is an uncomfortable truth that we must face, especially in the face of the strange world of quantum mechanics: Science has its limits. 

In his 2014 book, The Island of Knowledge: The Limits of Science and the Search for Meaning, professor of physics and astronomy at Dartmouth College Dr. Marcelo Gleiser discusses the limits of science and its implication for our understanding of the world around us, arguing that our understanding of the world will always remain incomplete. By recounting the history of Western science from the ancient Greeks to the current world of quantum mechanics, Gleiser posits that even while our understanding and knowledge of the world grow, so does our ignorance of it. Utilizing a balance of hard science with philosophical musings, Gleiser hopes to capture the reader’s curiosity, unseating us from our comfortable certainty, and pushing us towards greater horizons of discovery. 

Overview:

The title of the book comes from Gleiser’s analogy regarding the nature of knowledge. According to Gleiser, our understanding of the world around us is like a lone island amidst an ever-expansive sea. The more we learn about the world, the more the island grows; yet, the more the island grows, the more we understand the vastness of the ocean. For Gleiser, the sea is infinitely expansive, and as such, our knowledge of the world will never be complete. Rather, as we discover more of the natural world, we increasingly realize just how little we do know and how much is left to discover; essentially, as soon as we answer one question, ten more arise to take its place. 

Accordingly, Gleiser begins his investigation into the limits of science by giving us a brief history of science, with a particular emphasis on physics. Tracing the development of physics from the ancient world to the present day, Gleiser hopes to expose the various ways in which scientists have developed complex theories about the universe, only to be usurped by better and more accurate explanatory models. Gleiser does this in three main parts of the book. Part One is concerned with cosmology, as it traces the development of cosmological models of the universe from Aristotle’s earth-centered cosmos to modern string theory and multiverse models of the Universe. Along the way, in traditional fashion, Gleiser introduces readers to the ideas of Copernicus, Newton, Einstein, and more as he explains how each of their successors upended their explanatory models of the universe.

After examining cosmology on a macro-level, Part Two concerns the micro-world of quantum mechanics. Taking us from Atomists of the ancient world to the role of alchemy as a precursor to chemistry, and finally, to the strange world of quantum mechanics, Gleiser shows us the development of competing theories of the fundamental building blocks of the universe. He spends the bulk of this section discussing the weirdness of the quantum realm, such as the unpredictable nature of electrons and photons, as well as the still-bewildering process of quantum entanglement and nonlocality. Gleiser, not content with the Copenhagen Interpretation of quantum mechanics (aka quantum mechanics does not apply on the macro-level of our experience), contemplates the implications of quantum mechanics for our own understanding of the world, including our ability to even measure quantum phenomena. As such, in this section of the book, the subject does take a sharp turn from history to theoretical physics very quickly, and Gleiser has a penchant for constantly focusing much of his time on quantum mechanics (for good reason, as it gets really weird and serves as a great illustration for our current limits of scientific understanding). While quantum entanglement and wave functions may be heavy-duty reading for most people, much to his credit, Gleiser keeps most of the mathematical details and equations within the endnotes.  While the subject matter is a lot to take in, Gleiser does utilize a litany of analogies and examples in order to make it accessible.

Finally, in the third and final section of the book, Gleiser puts forth some musings and speculations regarding the implications of quantum theory for other branches of inquiry, such as computer science, neurology, and theories of the mind. Here, Gleiser contemplates the use of quantum theory for applications such as quantum computing, artificial intelligence, the problem of consciousness, and simulation theory. While the shortest and weakest chapter of the work, Gleiser connects it to the rest of the book by revealing the interconnected links between philosophy (particularly epistemology and metaphysics) and science. Ultimately, science helps us to understand the world around us and push ourselves to the limit of understanding. As humans, we are meaning-seeking beings trying to make sense of the world around us, and the strangeness of the quantum world reveals our limitations in understanding. Even the intellectual giants such as Aristotle, Newton, and Einstein understood the limitations of their theories, and so must we approach our understanding of the world with similar humility. Through this work, Gleiser argues that while we can advance our knowledge of the world around us, at the end of our searching, there will always be an element of suspended, unknowable belief. While this may be discouraging and defeating to some, Gleiser remains optimistic. Regarding our place in the cosmos, and echoing the sentiments of Dr. Manhattan comforting the Silk Specter in that pivotal scene on Mars in Alan Moore’s Watchmen, Gleiser asserts that in the midst of a strange and seemingly indifferent universe, “we matter because we are rare” (192). For Gleiser, the unknowable should not be frustrating or disheartening, but rather awe-inspiring, pushing us ever further in our quest for discovery. 

Commendations

First of all, Gleiser is a clear and level-headed communicator, and he writes with the voice of a teacher who is passionate and well-versed in the subject.  While many topics in this book can be heady and difficult to grasp, he takes his time getting into the more complex bits, easing the reader into it by slowly building his argument. Gleiser shies away from using technical jargon, and he is sure to sprinkle in some personal stories as well as imaginative examples to illustrate his points. Gleiser’s book gives us a cursory guide into the limitations of our current scientific understanding, explaining developments and failed models throughout the centuries (which, although different in scope, articulation, and purpose, reminded me of Mac’s humorous presentation in It’s Always Sunny in Philadelphia, “Science is a Liar Sometimes”). Essentially, Gleiser argues that our limitations arise from two specific problems: the tools and technology at our disposal and the inherent limitation of our brains to comprehend the infinite universe. Gleiser is pragmatic in his approach to science, framing it as a way to construct models about the world through observation, testing, and repeatability. 

Furthermore, in a surprising break from many other popular scientists, Gleiser refuses to denigrate the role of philosophy and metaphysics. Gleiser is careful to not overestimate the explanatory potential of science, making the point that science is much more concerned with describing the natural world, rather than explaining it. Reining in the overzealous claims of scientific realism, Gleiser cautions, “When it comes to physical reality, there are no final explanations, but ever more efficient descriptions” (185). While some of Gleiser’s summations of philosophy are a bit surface-level, he displays a kind of epistemological humility that is rare among scholars, and his rejection of rigid, dogmatic scientism is certainly commendable. Gleiser is respectful and charitable to both philosophy and science as legitimate avenues of inquiry into the nature of the universe. Gleiser connects the pre-Socratic understanding of the world to the present moment, arguing that the motivations and theories we propose are often very similar and persistent across the centuries, even if we have better tools and methods of measuring at our disposal. This perpetual process of discovery is what excites Gleiser about science. It is a field that is always open to change in the face of new discoveries and data, challenging our preconceived notions of the universe and helping us to grow and expand our own understanding of the world around us. 

Finally, Gleiser makes a few asides and concessions throughout the texts that I deeply respect. As someone who’s research interest includes the intersection between religion, magic, and medicine, I often try to bridge the gap between pre-modern attempts at science and the Scientific Revolution. Often, when scientists and scholars describe the rise of modern science, for example, they will praise Newton’s discovery of the theory of gravity while casting his fascination with alchemy and the occult as a quirky, unfortunate, and embarrassing byproduct of his time. By distancing these figures from their strange occult roots, many scholars actually miss that these discoveries were influenced by their strange beliefs in alchemy, astrology, etc. Thus, we also see alchemy serving as a precursor to modern chemistry, providing the fundamental principles for the scientific discipline, muddled and misguided as they were. Many historians of science are embarrassed that their scientific heroes could have such seemingly irrational and silly beliefs, not realizing that these beliefs helped to serve as the foundations for their scientific discoveries. Gleiser rightly brings these forces back to the foreground of the scientific narrative, and it is so breathtakingly refreshing to see a scholar and scientist recognize these dimensions of history, treating them holistically with nuance. 

Critique

While much of Gleiser’s work here is to be commended, there are just a few shortcomings in this text. First of all, this book is incredibly ambitious in scope, as Gleiser attempts to provide a wide historical perspective to the development of science. This wide breadth of historical narrative, while illuminating at times, can often, by necessity, lack a certain depth. Especially toward the start of the narrative, Gleiser does his best to summarize philosophical concepts, but can often be a bit over-simplistic and cursory. To his credit, Gleiser’s summation of ancient Greek philosophy is passable for a popular science book, but several of his comments on the moral issues of artificial intelligence and neuroscience leave much to be desired. However, Gleiser isn’t a philosopher; he’s a scientist, and one cannot expect him to be equally thorough on a topic outside of his field. Yet, especially in the third section of the book, I wish he had expanded on some of his thoughts and implications on the problems of consciousness. 

Furthermore, Gleiser, along with most historians of science, glosses over the contributions of the Islamic world and the Middle Ages toward the development of science. As with most popular histories of science, Gleiser recounts the history of science by beginning with the ancient Greeks before discussing Copernicus, Galileo, and Newton in the early modern era, and then finishes by discussing Einstein, Bohr, and Heisenberg in the 20th century. Vast swaths of history are essentially erased from the narrative of science, and I do understand the reasoning. Large advances and revolutions in scientific thought occurred in these eras, and the epochs in between are much more difficult to address. Furthermore, I understand that one cannot recount everything within the history of science within one popular science book. Yet, exempting one reference to alchemy and the work of eighth-century alchemist Jabir ibn Hayyan, there is very little reference to the contribution of the Middle Ages or the Islamic world, both of which set the fundamental building blocks for the Scientific Revolution. 

Finally, as the book progresses, much of it is dedicated to understanding the strange and fascinating details regarding the realm of quantum mechanics. While it is a compelling branch of physics and lends support to Gleiser’s overall thesis, I found that Gleiser’s focus on the quantum realm could be a bit confusing for many readers. While personally, I do have an affinity and special interest in quantum mechanics, those who are not as interested in the subject might find themselves overwhelmed and struggling through many chapters. Much to his credit, Gleiser does attempt to make quantum mechanics understandable through the plentiful use of examples and metaphors; even still, the bulk of the book is dedicated towards quantum mechanics, so one’s enjoyment of this book will most likely depend on their interest in the subject. 

Conclusion

Overall, Gleiser gives us a robust account of the history of science and our current understanding of quantum mechanics, showing us that the quest for knowledge is only beginning. While there’s not much within the book that’s particularly new or groundbreaking, it is still a wonderful introduction/refresher into the limits of the scientific enterprise. For the reader who is interested in cosmology, physics, and quantum mechanics, then this book is a great starting point into some basic concepts, even if you have no prior knowledge. For anyone interested in the history of science, the limits of what we can know about the world around us, and what we might hope to understand beyond those limits, then this book will serve as a quick, gripping, and wholly worthwhile read.