Genius_ The Life and Science of Richard Feynman - James Gleick [261]
His own community had largely left behind questions with the spirit that first drove him toward physics. An intellectual distance had opened between the subatomic particle universe and the realm of ordinary phenomena—the magic that nature reveals to children. In The Feynman Lectures he spoke allegorically of the beauty of a rainbow. Imagine a world in which scientists could not see a rainbow: they might discover it, but could they sense its beauty? The essence of a thing does not always lie in the microscopic details. He supposed that the blind scientists learned that, in some weathers, the intensity of radiation plotted against wavelength at a certain direction in the sky would show a bump, and the bump would shift from one wavelength to another as the angle of the instrument shifted. “Then one day,” he said, “the physical review of the blind men might publish a technical article with the title ‘The Intensity of Radiation as a Function of Angle under Certain Conditions of the Weather.’” Feynman had no quarrel with beauty—our human illusion, our projection of sentiment onto a reality of radiation phenomena.
“We are all reductionists today,” said Steven Weinberg—meaning that we seek the deepest explanatory principles in the elementary particles that underlie ordinary matter. He spoke for many particle physicists but not for Feynman. Understanding the principles at the lowest level of the hierarchy—the smallest length-scales—is not the same as understanding nature. So much lies outside the accelerators’ domain, even if it is in some sense reducible to elementary particles. Chaotic turbulence; the large-scale structures that emerge in complex systems; life itself: Feynman spoke of “the infinite variety and novelty of phenomena that can be generated from such simple principles”—phenomena that are “in the equations; we just haven’t found the way to get them out.”
The test of science is its ability to predict. Had you never visited the earth, could you predict the thunderstorms, the volcanoes, the ocean waves, the auroras, and the colorful sunset? …
The next great era of awakening of human intellect may well produce a method of understanding the qualitative content of equations. Today we cannot. Today we cannot see that the water-flow equations contain such things as the barber pole structure of turbulence that one sees between rotating cylinders. Today we cannot see whether Schrödinger’s equation contains frogs, musical composers, or morality—or whether it does not.
Physicists’ models are like maps: never final, never complete until they grow as large and complex as the reality they represent. Einstein compared physics to the conception a person might assemble of the interior mechanism of a closed watch: he might build a plausible model to account for the rhythmic ticking, the sweep of the hands, but he could never be certain. “He may also believe in the existence of the ideal limit of knowledge and that it is approached by the human mind,” Einstein said. “He may call this ideal limit the objective truth.” It was a simpler time. In Feynman’s era, knowledge advanced, but the ideal of objective truth receded deeper into the haze beyond the vision of science. Quantum theory had left an impossible question dangling in the air. One physicist chose to answer it by quoting Feynman, “one of the great philosophers of our time, whose view of the matter I have taken the liberty of quoting in the form of the poetry it surely is”:
We have always had a great deal of difficulty
understanding the world view
that quantum mechanics represents.
At least I do,
because I’m an old enough man
that I haven’t got to the point
that this stuff is obvious to me.
Okay, I still get nervous