Impossibility: The Limits of Science and the Science of Limits

In Impossibility, John D. Barrow--one of our most elegant and accomplished science writers--argues convincingly that there are limits to human discovery, that there are things that are ultimately unknowable, undoable, or unreachable. Barrow first examines the limits of the human mind: our brain evolved to meet the demands of our immediate environment, and much that lies outside this small circle may also lie outside our understanding. He investigates practical impossibilities, such as those imposed by complexity, uncomputability, or the finiteness of time, space, and resources. Is the universe finite or infinite? Can information be transmitted faster than the speed of light? The book also examines deeper theoretical restrictions on our ability to know, including Godel's theorem, which proved that there were things that could not be proved. Finally, having explored the limits imposed on us from without, Barrow considers whether there are limits we should impose upon ourselves. Weaving together this intriguing tapestry, Barrow illuminates some of the most profound questions of science, from the possibility of time travel to the very structure of the universe.

Perhaps it's a harbinger of the end of science that so much attention is being paid to the impossible. In Impossibility, astronomer John D. Barrow outlines a maturation pattern for areas of deep human inquiry that includes an adolescence of exciting discoveries, new formulas, and unusual predictions. As science has matured, our confidence in it has grown. We expect that science has answers, that its predictive powers are mostly accurate. But what happens when the science gets old? Oddly enough, it seems to have started trying to find the end of its own usefulness--its formulas "predict that there are things which they cannot predict, observations which cannot be made, statements whose truth they can neither affirm nor deny."

Barrow's book is a fairly tough read, delving into topics as varied as theology, art, mathematics, and cosmology in its quest to define impossibility. But for those who have noticed that, "Scientists seem no longer content merely to describe what they have done or what Nature is like; they are keen to tell their audience what their discoveries mean for an ever-widening range of deep philosophical questions," Impossibility is an intriguing look at the evolution of our thoughts on knowing everything. Without limits, there would be no science, and though our imaginations may roam freely through the realms of impossibility, we may find in the end that "what cannot be known is more revealing than what can." --Therese Littleton