We must recognise that because of the very nature of human inquiry every age has its unknowables. The question we need to address, then, is whether certain unknowables are here to stay or whether they can be dealt with in due course. Must every question have an answer? — Marcelo Gleiser Picture an island. The ocean, in all directions, stretches to the horizon. The island is what we know and understand of the universe. The ocean recedes and advances unevenly around the coastline as we learn more, subsuming what turned out to be false and revealing new land when a new “truth” is affirmed. This is the central metaphor in Marcelo Gleiser‘s endlessly fascinating The Island of Knowledge: The Limits of Science and the Search for Meaning (Basic Books, 2014). In this free-ranging, accessible account of what we know, how we came to know it, and what we can maybe never know, Gleiser reveals wonders both cosmic and quantum. Although its subtitle, “The Limits of Science and the Search for Meaning,” may sound defeatist, The Island of Knowledge is instead inspiring. It’s a tribute to the extraordinary enterprise of the world’s scientists and philosophers over the last few millennia. It’s a paean to our […]