When We Cease to Understand the World

by Benjamín Labatut

Did all describe the same object, or did each represent a possible world? Schrödinger considered the second possibility: those multiple waves would be the first glimpse of something completely new, each a brief flash of a universe that was born when the electron leapt from one state to the other, branching out to populate the infinite, like the jewels of Indra’s net. But such a thing was inconceivable. Rack his brain as he might, he could not understand how he had strayed so far from his original intent. He had hoped to simplify the atomic world, had looked for a common attribute to all things, and had given birth to a greater mystery.

and that seemed to exclude the possibility that a given phenomenon should possess certain perfectly defined attributes simultaneously. His original intuition had been correct: it was impossible to “see” a quantum entity for the simple reason that it did not have a single identity. Illuminating one of its properties necessarily obscured the other. The best description of a quantum system was neither an image nor a metaphor, but rather a set of numbers.

In philosophical terms, he told him as he took his arm, this was the end of determinism. Heisenberg’s uncertainty principle shredded the hopes of all those who had put their faith in the clockwork universe Newtonian physics had promised. According to the determinists, if one could reveal the laws that governed matter, one could reach back to the most archaic past and predict the most distant future. If everything that occurred was the direct consequence of a prior state, then merely by looking at the present and running the equations it would be possible to achieve a godlike knowledge of the universe.

Never before or again were so many geniuses united beneath the same roof: seventeen of them had won, or would go on to win, the Nobel Prize, including Paul Dirac, Wolfgang Pauli, Max Planck and Marie Curie, who had won it twice and was overseeing the conference committee along with Hendrik Lorentz and Albert Einstein.

That afternoon, Heisenberg and Bohr presented their vision of quantum mechanics, which would come to be known as the Copenhagen Interpretation.

Reality, they said to those present, does not exist as something separate from the act of observation. A quantum object has no intrinsic properties. An electron is not in any fixed place until it is measured; it is only in that instant that it appears. Before being measured, it has no attributes; prior to observation, it cannot even be conceived of. It exists in a specific manner when it is detected by a specific instrument. Between one measurement and the next, there is no point in asking how it moves, what it is, or where it is located. Like the moon in Buddhism, a particle does not exist: it is the act of measuring that makes it a real object.

They live in worlds of potentialities, Heisenberg explained; they are not things, but possibilities.

Einstein had to yield. He had not found a single inconsistency in Bohr’s reasoning. He accepted defeat grudgingly, and condensed all his hatred of quantum mechanics in a phrase he would repeat time and again in the succeeding years, one he practically spat in the Dane’s face before his departure: “God does not play dice with the universe!”

He struggled to arrive at a grand unified theory and died without achieving it, admired by all, but completely alienated from the younger generations, who seemed to have accepted

Fame accompanied him until his death in January 1961 at the age of seventy-three from a final attack of tuberculosis that besieged him in Vienna. His equation remains a pillar of modern physics, though in a hundred years nobody has been able to unravel the mystery of the wave function.

The night gardener told me that the man who invented modern-day nitrogen fertilizers—a German chemist called Fritz Haber—was also the first man to create a weapon of mass destruction, namely chlorine gas, which he poured into the trenches of the First World War. His green gas killed thousands and made countless soldiers claw at their throats as the poison boiled inside their lungs, drowning them in their own vomit and phlegm, while his fertilizer, which he harvested from the nitrogen present in the air itself, saved hundreds of millions from famine and fuelled our current overpopulation. Today nitrogen is more than plentiful, but in centuries past wars were fought over bird and bat shit, and thieves ransacked the bones of the Egyptian pharaohs to steal the nitrogen hidden in their bones. According to the night gardener, the

The night gardener’s decision to drop out of life was not merely because of his admiration for Grothendieck, of course. He had also gone through a bad divorce, become estranged from his only daughter and been diagnosed with skin cancer, but he insisted that all of that, however painful, was secondary to the sudden realization that it was mathematics—not nuclear weapons, computers, biological warfare or our climate Armageddon—which was changing our world to the point where, in a couple of decades at most, we would simply not be able to grasp what being human really meant.

We can pull atoms apart, peer back at the first light and predict the end of the universe with just a handful of equations, squiggly lines and arcane symbols that normal people cannot fathom, even though they hold sway over their lives. But it’s not just regular folks; even scientists no longer comprehend the world. Take quantum mechanics, the crown jewel of our species, the most accurate, far-ranging and beautiful of all our physical theories. It lies behind the supremacy of our smartphones, behind the Internet, behind the coming promise of godlike computing power. It has completely reshaped our world. We know how to use it, it works as if by some strange miracle, and yet there is not a human soul, alive or dead, who actually gets it. The mind cannot come to grips with its paradoxes and contradictions. It’s as if the theory had fallen to earth from another planet, and we simply scamper around it like apes, toying and playing with it, but with no true understanding.

The night gardener once asked me if I knew how citrus trees died: when they reach old age, if they are not cut down and they manage to survive drought, disease and innumerable attacks of pests, fungi and plagues, they succumb from overabundance. When they come to the end of their life cycle, they put out a final, massive crop of lemons. In their last spring their flowers bud and blossom in enormous bunches and fill the air with a smell so sweet that it stings your nostrils from two blocks away; then their fruits ripen all at once, whole limbs break off due to their excessive weight, and after a few weeks the ground is covered with rotting lemons.

and such displays of overripening feel out of character for a plant and more akin to our own species, with its uncontrolled, devastating growth. I asked him how long my own citrus had to live. He told me that there was no way to know, at least not without cutting it down and looking inside its trunk. But, really, who would want to do that?