We’ve just recently begun to understand how the planets in our solar system evolved. Dan Levitt looks at the Soviet mathematician who spent a decade working on a subject that most astronomers had given up on, and was met with disinterest and doubt when he finally solved it in the excerpt below from “What’s Gotten Into You” (HarperCollins, 2023).
The atoms that would become humanity sailed in huge clouds of gas and dust over 4.8 billion years ago, toward… well, nothing. There were no planets, no solar system, and no Earth. For a long time, scientists couldn’t explain how our solid planet, let alone one so friendly to life, came to be. How did our now-rocky planet appear, seemingly by magic, from an ethereal cloud of gas and dust? When and how did Earth become so hospitable to life? And what hardships were our molecules forced to endure before life could evolve?
Scientists would discover that our atoms could only produce life after enduring agonizing collisions, meltdowns, and bombardments – disasters that dwarfed any destruction ever observed by humanity.
Explaining how our planets formed appeared to be so difficult that most astronomers had given up by the 1950s. Their theories appeared to be pointless. Two centuries ago, the German philosopher Immanuel Kant and the French scholar Pierre-Simon Laplace correctly theorized that gravity reeled in a massive spinning cloud of gas and dust so tightly that intense temperatures and pressures ignited it into a star — our sun. But how did the planets come to be? They proposed that a disk of wayward dust and gases continued to rotate around the Sun, breaking up into smaller clouds that formed the planets. No one, however, could explain how the disk broke up or how the planets formed from these smaller clouds.
In 1917, the Englishman James Jeans took a novel approach that Cecilia Payne’s peers supported. Jeans hypothesized that a passing star’s gravitational pull was so strong that it pulled enormous chunks of gas off the sun’s surface, which created the planets. Others believed that our planets were debris left over after star crashes. Nobody knew how nine distant planets formed from such a collision. It appeared as possible as putting wet laundry in the dryer and then opening it to discover your clothing not only dry, but perfectly folded. Only a few astronomers remained interested in the topic.The astronomer George Wetherill described it as “innocent entertainment” or “outrageous speculation.” It was just impossible for us to see that far back in time. Additionally, you can also read about- The Big Bang Facts: 8 Amazing Things You Didn’t Know
Nonetheless, in the late 1950s, at the height of the Cold War, a young physicist in the Soviet Union resolved to confront the problem head on – with mathematics. Viktor Safronov was his name. Safronov was short in stature and suffered from malaria as a result of his military training in Azerbaijan during WWII. He was modest, humble, and unusually intelligent. He excelled at Moscow University, earning advanced degrees in physics and mathematics. Otto Schmidt, a mathematician, geophysicist, and polar explorer, recognized his brilliance and attracted him to the Soviet Academy of Sciences.
Schmidt, like Kant and Laplace before him, believed that our planets were formed from a disk of gas and dust around the Sun. He needed someone with technical knowledge to assist him in figuring out how, and the soft-spoken Safronov was a great mathematician.
Safronov began in the outset at an office at the Academy of Sciences. He embarked on the arduous challenge of explaining how trillions upon trillions of gas and dust particles could construct a solar system. He’d try it with mathematics, especially statistics and fluid dynamics equations, which describe the flow of gases and liquids. All of this without the need of computers. In fact, his absence of a computer may have aided him by pushing him to hone his already razor-sharp intuition.
Safronov began by thinking that our solar system created when the immense primordial cloud of dust and gas, which we left drifting in space in the previous chapter, was changed into a star by the unrelenting pull of gravity. Almost all of it (99%, we now know) turned into our sun. However, residual remains were too far away to be carried into the sun, but not far enough to completely escape its grasp. Instead, gravity and rotation’s centripetal force flattened this cloud into a disk of dust and gases around the sun.
Safronov, who astounded colleagues with his ability to make quick mathematical estimates, set out to calculate what happened when tiny particles within the disk collided and subsequently struck their neighbors. He diligently endeavored to quantify the impacts of trillions upon trillions of collisions with pencil and paper and a slide rule, possibly in the quiet of a library where Soviet scientists often retired from the hubbub of vast shared offices. That was a huge undertaking, with or without a computer. In example, one would expect that estimating a hurricane’s route from the initial water droplets accumulating in clouds would be simple.
Safronov realized that the swarm of cosmic dust and gas around the sun would be moving in the same direction and at nearly the same speed. When the particles collided with one another, they would sometimes stay together like snowflakes. More collisions resulted in larger and larger clusters, eventually reaching the size of rocks, ocean liners, mountain ranges, and, finally, mini-planets. Building on his understanding, Safronov listed most of the fundamental challenges that scientists would need to address in order to explain the origins of our planets. And he vanquished many of them with mathematical boldness.
For years, he had nearly the whole area of planetary formation to himself. Most of his Soviet colleagues were dubious and indifferent; his research appeared fanciful and devoid of evidence. Then, in 1969, Safronov released a tiny paperback that served as a retrospective of his decade of solitary effort. He gave a copy to a visiting American graduate student, who forwarded it to NASA with the recommendation that it be published. Three years later, an English version was released in the United States.
It would fundamentally alter our knowledge of how the Earth and all other planets are formed.