“WHEN YOU HEAR someone arguing that scientific knowledge is limited, you could be excused for expecting to find a creationist or a tobacco industry spokesperson. Instead, here we have a distinguished Ivy League physicist contending that science gives us only a fraction of reality. In The Island of Knowledge, Marcelo Gleiser wants to forge a third way between scientism and obscurantism whereby we can embrace both the power and incompleteness of science.”
“Many people suggest we should trust science because it is almost finished — final explanations for everything from quarks to consciousness are here or just around the corner. As Gleiser tells us, this is a dangerously distorted perspective. He provides a compelling list of reasons to think that science is not done and, indeed, that it will never be done. Some of these reasons are technical, some conceptual. As our instruments improve, we will see things that we cannot even conceive of now. The limitation of light speed and our particular location in the history of the universe mean that we can only observe a tiny slice of the cosmos. Gödel’s incompleteness theorems and the halting problem keep us from any mathematical road to final truth.”
“To illustrate the consequences of these limits Gleiser introduces his metaphor of the “island of knowledge.” Like an active volcano, this island is slowly growing as new knowledge is added. We should not think of the island as ever being “done” because we can always add more surface area, even if occasionally a peninsula gets washed away by the rogue wave of a disproving experiment. And as the island grows, the shoreline — the dark edge of our ignorance — continues to expand. A bigger island only presents us with more mysteries.”
“This means we can never know all the truths about reality and, indeed, that a “theory of everything” is a pointless quest. A “unified theory” is impossible because we will never even know all of the data and ideas that would need to be unified. Gleiser dismisses projects such as string theory as little better than romantic fantasies. Even more strongly, he contends that we have no access to universal knowledge of any kind; we are all trapped in our own little corners of space-time, behind our deeply flawed brains. Even mathematical truths are simply the systems we find useful for solving our particular problems at a particular point in time.”
“Gleiser wants us to be left with an image of science as an open-ended pursuit: an island that can always expand, not a bucket that is almost full. It can never be finished. We can, and should, push on our limits. Indeed, this book is a compelling call to a new “way of living, a collective aspiration to grow as a species in a world filled with mystery, fear, and wonder.””
“Perhaps this is a fruitful way to think about changes within science. Instead of Kuhn’s political metaphor of the “revolution,” where an entirely new institution completely replaces a previous one, here we have fierce competition for finite niches. Then, eventually, a new balance forms between invasive and native species. Maybe Copernicanism invaded the island of Aristotelianism, and dominated the lowlands of positional astronomy while the Peripatetics continued to thrive in the highlands of moral philosophy and aesthetics.”