Shelf Help: All our known unknowns

‘Known Unknowns’ was a term popularised by former U.S. Secretary of Defence Donald Rumsfeld. While he used it in the context of Saddam Hussein’s Iraq, it is now a staple of risk assessment studies and can be stretched to any field of knowledge that is expanding so rapidly that even its practitioners struggle to keep up. The most pervasive of the Known Unknowns is dark matter, the cosmic bubble wrap of our universe making up 85 per cent of the mass of the universe. Physicist Lisa Randall in her latest book, Dark Matterand the Dinosaurs , expounds an intriguing hypothesis that dark matter — impervious to light and our most acute telescopes but perceptible only through the whispers of gravity — may have caused a comet-like object to crash into Earth and extinguish the dinosaurs 66 million years ago.

It is an evocative example of how real, observable, life-altering events are brought about by equally real, unobservable objects, hiding in plain sight. Randall only speaks about one domain of knowledge — astrophysics — where humanity sees itself as armed with knowledge formidable enough to float cameras all the way to Pluto but is hard-pressed to explain why space is so empty and yet weighty enough to trigger cataclysms. Dealing with the invisible, in a sense, is what science is all about.

In the 2014 book,

Invisible: The Dangerous Allure of the Unseen , science writer Philip Ball, whose forte is chemistry, dives into folklore, myth, stage magic, Victorian science, science fiction and the detective novel to persuasively argue that through the ages, the way thinkers have interpreted invisibility has significantly shaped scientific thought as well as the sensibilities of its contemporaneous technology. Ball builds a case to argue that in interpreting and making sense of the real world, the best scientific explanations through the ages and those of today couldn’t, and cannot, help resorting to ideas of ‘invisible forces’, ‘the paranormal’ and ‘the occult’, and this is true as much of 19th century James Clerk Maxwell’s seminal electromagnetic field theory as of the edgiest, cosmological ideas of today, including string theory, dark energy and dark matter.

Then there are the other invisible forces — more known unknowns — that shape our personalities. For Freud it may have been just id, ego and superego but science writer Anil Ananthaswamy, in

The Man Who Wasn’t There... , described cases of people who couldn’t bear to live with their perfectly healthy limbs or were convinced they were dead, were led by impulses, urges, genes and nerves that were prosaic but subtly tweaked in invisible, still unfathomable ways.

jacob.koshy@thehindu.co.in