Reality Is Not What It Seems by Carlo Rovelli review – physics versus certainty

Carlo Rovelli’s slim poetic meditation Seven Brief Lessons on Physics managed to clarify the troubling uncertainties of Einsteinian relativity, quantum theory and other physical exotica. Less than 80 pages long, it became one of the fastest-selling science books ever, and has now sold a million copies worldwide. Not since Stephen Hawking’s A Brief History of Time had there been such a consensual success in the science book market; in the author’s native Italy the lessons even outsold Fifty Shades of Grey.

Reality Is Not What It Seems – a deeper, more intellectually challenging meditation – outlines for the general reader some of the key developments in physics from the ancient Greek philosophers and the Roman poet Lucretius to the present day. In the Italian professor’s elucidation, physics goes deeper than any other science into the riddle of existence. The laws of physics – gravity, energy, motion – underpin those of chemistry, astrophysics and meteorology combined. So an understanding of the world requires some grasp of physics. This book aims to make that grasp easier for the layperson.

It should be noted, however, that Reality first came out in Italy in 2014 before Seven Lessons, so, with this edition translated into English by Simon Carnell and Erica Segre, we are getting Rovelli in reverse order of publication. No matter. In exquisitely written pages he seeks to bridge the divide between what CP Snow called the “Two Cultures” of science and the arts. According to Rovelli, this divide widened catastrophically in Italy after the 1923 fascist school reforms ensured that the classics provided the core curriculum, not science. He has never quite forgiven Italy’s pro-Mussolini philosopher Benedetto Croce for his conviction that “scientific problems are not real ones” (Croce later turned against Mussolini).

In a superb chapter on Dante and his conception of paradise and the cosmos, Rovelli writes: “Our culture is foolish to keep science and poetry separated,” adding: “they are two tools to open our eyes to the complexity and beauty of the world.” Like the Italian scientist-writer Primo Levi, Rovelli sees no incompatibility between the two cultures, only mutual attraction. In Lucretius’s long philosophical poem, On the Nature of Things, he finds a luminous celebration of the mysteries of the natural world that anticipated a large part of contemporary physics. Atoms are the sole “building blocks” of the universe, Lucretius observed. Lucretius did not know it, but he was writing about the quintessential atom of life – carbon – at a time when atomic theory did not exist. On the Nature of Things only became “modern” in 1417, however, when the papal scribe and humanist Poggio Bracciolini chanced on the last surviving manuscript of the poem in a German monastery. Subsequently, the poem was translated and disseminated widely. Shakespeare struck a Lucretian note in Romeo and Juliet, Rovelli writes, where the phantasmagoric Queen Mab is believed to have a “team of little atomies” at her command.

Certainly Lucretius was ahead of his time. Girolamo Savonarola, the firebrand church reformer of Renaissance Florence, fulminated against his pagan-era theory of atoms, which seemed to militate against Christian absolutism. Throughout, Rovelli repudiates religious fundamentalists of any denomination – but also rejects the idea that science is ever settled. “The search for knowledge is not nourished by certainty: it is nourished by a radical distrust in certainty,” he comments in a chapter on loop quantum gravity theory. Scientists such as Richard Dawkins who pretend to atheist omniscience are, Rovelli argues, no less intolerant or prejudiced; the world is not necessarily as Dawkins thinks it is.

Science is not and never has been about certainty. “Only by keeping in mind that our beliefs may turn out to be wrong is it possible to free ourselves from wrong ideas,” Rovelli writes axiomatically. The joy of physics lies partly in its willingness to be wrong and to explore the world experimentally. Dante’s Ulysses reminds his companions that we are not made “to live like brutes, but to seek virtue and knowledge”. Of course, curiosity-driven researchers such as Galileo Galilei incurred the wrath of the Catholic church in the 17th century by putting divine laws to test and conducting investigations. (“For in much wisdom is much grief”: Ecclesiastes.) In a brilliant chapter, Rovelli extols Galileo as a proto-physicist who “tasted” the apple of knowledge and was jailed by the ecclesiastical authorities for daring to exercise his curiosity.

A “curious” person (from the Latin cura, “care”) was originally understood to be somebody who undertook investigations with due diligence. One such was the Belgian Jesuit-educated priest Georges Lemaître, who, in 1927, developed what would become known as Big Bang theory. Nobody would claim that these ideas were easy, but Rovelli writes with bracing clarity of Lemaître’s discovery that the universe is not fixed, but ever-expanding. The Catholic priest personified the modern “struggle with curiosity” and even what it means to be human.

Along the way, Rovelli discourses (not always clearly) on spatio-temporal continuums, the infinitude of matter, gravitational waves and other abstract ideas. The “real magic” of 20th-century physics begins with Einstein: his notion that time and space cannot be separated (the concept of “spacetime”) posed a threat to the cosy certainties of anti-relativity scientists. Unlike the wafer-thin Lessons, this book by Rovelli will not fit easily into a pocket, but its lapidary integration of science and literature is a marvel. “Is the world not marvellous?” Rovelli asks. Yes, signor professore, we do believe it is.