The Terror of Threes in the Heavens and on Earth
Physicists have long explored how phenomena in groups of three can sow chaos. A new three-body problem, they warn, could lead to not only global races for new armaments but also thermonuclear war.
By William J. Broad
June 26, 2023 | Updated 1:52 p.m. ET
Isaac Newton was baffled. He was already famous for discovering how gravity holds the universe together and for using that knowledge to predict the movements of celestial bodies, such as the moon’s path around the Earth. Now, by taking the sun’s gravitational tugs into account, he sought to improve his lunar predictions. Instead, it made them worse.
The setback, Newton’s friend Edmond Halley reported, “made his head ache, and kept him awake so often, that he would think of it no more.” Newton felt his defeat so keenly that he recalled it more than once in his old age.
Today it’s called the three-body problem. Famous in science and science fiction for orbital perturbations and chaotic phenomena, it’s recently become a concern of atomic experts and military planners. As Beijing rapidly expands its nuclear arsenal, they warn that the world of atomic superpowers is about to escalate to three from two. The outcome, they add, compared with the Moscow-Washington standoff, now 70 years old, could represent a dangerous new kind of unthinkable.
The looming era could encourage “states to resort to nuclear weapons in a crisis,” Andrew F. Krepinevich Jr., a senior fellow at the Center for a New American Security, recently warned. He cited the natural instabilities observed by physicists and astronomers as a portent.
Experts say the tripolar age could put human survival at risk. But they also cite a number of three-body lessons from nature — starting with Newton’s — that illuminate the issue and suggest possible ways forward. So far, however, no answer stands out. The world’s nuclear thinkers are finding the knotty topic to be as intractable as it was for Newton.
“We have a conceptual problem,” said Ernest J. Moniz, a physicist who as the secretary of energy in the Obama administration oversaw the U.S. nuclear arsenal. “We’ve got to change the traditional approach of equalizing weapons or strategic delivery systems, but how to do that is still unclear.”
France A. Córdova, an astrophysicist and past director of the National Science Foundation, said the study of three-body phenomena in the natural sciences could nonetheless help reveal the military risks. “Things are changing very rapidly,” she said. “Anything that helps in understanding that is great.”
Security-minded hawks want to expand the American arsenal in response to China’s nuclear rise and the threat of Beijing’s closing ranks with Moscow. Doves see a window for three-body downsizing. They want to break the problem into smaller and more manageable parts. For instance, they argue that Washington should deal with the two superpowers independently and seek diplomatic bonds that reinforce two-body stability.
Recently, the Biden administration called for a further simplification. Jake Sullivan, the national security adviser, argued that the American response should focus less on the quantity of the nation’s nuclear arms than on their quality. To deter attacks successfully, he said in a speech, the American military has no need for arms that “outnumber the combined total of our competitors.”Continue reading The Terror of Threes in the Heavens and on Earth