Consider, then, the sum total of our accumulated knowledge as constituting an island, which I call the “Island of Knowledge”….The Island’s growth has a surprising but essential consequence. Naively, we would expect that the more we know of the world, the closer we would be to some sort of final destination, which some call a Theory of Everything and others the ultimate nature of reality. However, holding on to our metaphor, we see that as the Island of Knowledge grows, so do the shores of our ignorance – the boundary between the known and the unknown. Learning more about the world doesn’t lead to a point closer to a final destination – whose existence is nothing but a hopeful assumption anyway – but to more questions and mysteries. The more we know, the more exposed we are to our ignorance, and the more we know to ask.
This past Spring, I took Prof. Gleiser’s science/philosophy mooc that focused on the question, Can we ever know the very essence of reality, or is there some knowledge that can never be within our grasp? Is it all a matter of developing technologies and learning how the universe works, or are there some things that simply can’t be discovered by reason, observation, and scientific method? This book was the basis for that course.
Prof. Gleiser has an eclectic approach to science. He’s a theoretical physicist, but the book is far more. I noticed a brief comment about his training towards the end: “I was twenty-seven and in search of ways of connecting the rational scientific approach that I was learning in school with a strong sense of spirituality I had nurtured since an early age.” That willingness to look beyond science, to philosophy, to human emotion and interaction, shows up clearly throughout this work. “If reason is the tool we use in science, it is not its motivation,” says Gleiser. While it’s mostly science, there is a strong thread of philosophy as well; this is a scientist comfortable with ideas of divinity. This was the course that inspired me to read Stephen Greenblatt’s The Swerve, a historical/philosophical work I enjoyed tremendously (and blogged about here).
Gleiser’s opinion is that we can’t know certain things, not because we don’t have good enough instruments or don’t have string theory nailed down yet, but because some things are simply unknowable. The “brain in vats” question is the classic example – how could we know? – but there’s also the limitation of the time horizon of the universe, and it seems there are most likely distance limitations at the small end of the scale as well. The more we know, the more we know we don’t know.
The book starts off with the pre-Socratics and the first inklinks of atomism. I discovered Ernst Mach, of Mach-1 fame, never accepted the existence of atoms, though their existence was theoretically proven during his lifetime; as I understand it (take this with a large shaker of salt), he didn’t say they didn’t exist, simply that he didn’t accept the existence of something that couldn’t be seen (he’d have changed his mind if he’d lived long enough to watch “A Boy and his Atom” on Youtube, a movie made with atoms). The first chapters move very quickly to Einstein, and the early 20th century forms a large part of the book as more and more questions arose for every answer. Once the quantum door was kicked in, everything was up for grabs, and we moved right along to the present.
While I’m sure I didn’t fully understand all the material on even an introductory academic level, it’s a very readable book, with good explanations and analogies that made most of the technical material at least partly understandable. For example:
[Q]uantum theory implies that there is a natural fuzziness to matter, a finite “smallness” to all things…. If we apply this notion to space, it is natural to expect that the same will be true: that there is a smallest distance of space beyond which nothing can be smaller. According to this view, space is not really a continuum but fuzzy, so that motion cannot proceed smoothly from point to point…. A competing view is to consider that it is not space that needs to be “quiltized” but the notion of point particles that needs to go.
When I was young and even more foolish than I am today, my then-boyfriend and I used to argue about whether the universe was fundamentally analog or digital (oh, come on, who hasn’t had those arguments). And when I read Euclid’s Elements, I was almost disappointed to find a proof that a plane must be continuous, thus analog. But maybe I was mistaken about that interpretation, since it appears scientists are still arguing about it.
I also enjoyed reading “But we do not know what electric charge or mass is…. Mass and charge do not exist per se; they only exist as part of the narrative we humans construct to describe the natural world.” I asked once in some course just what “charge” meant, since I can’t describe it without referring to electric charge, which of course is circular reasoning. So I’m always happy to find out that no one actually knows what “charge” is, beyond that it’s a quality some particles have that causes certain behaviors. This seems like the opposite of Ernst Mach’s problem with atoms: we can see it, feel it, but don’t know what it is. Mass seems to be in the same category.
How much can we know of the world? Can we know everything? Or are there fundamental limits to how much science can explain?…. From our past successes we are confident that, in time, part of what is currently hidden will be incorporated into the scientific narrative, unknowns that will become knowns. But as I will argue in this book, other parts will remain hidden, unknowables that are unavoidable, even if what is unknowable in one age may not be in the next one. We strive toward knowledge, always more knowledge, but must understand that we are, and will remain, surrounded by mystery.
This view is neither antiscientific nor defeatist. … Quite the contrary, it is the flirting with this mystery, the urge to go beyond the boundaries of the known, that feeds our creative impulse, that makes us want to know more.
It was this attitude that made this book so enjoyable for me. Back in the days when I argued about the nature of the universe for fun, I read a lot of general-readership science books, particularly Asimov. I somehow got away from that. Gleiser has written several other books on various aspects of physics and cosmology, and of course there are many other scientists writing for non-scientists these days. Maybe it’s time to get back into it again.