Nothing But The Truth

Science’s greatest weakness is also its greatest strength

The Search For Truth

Karen and Brad Emerson/Flickr CC By 2.0

Forty years ago, the legendary physicist Richard Feynman gave the commencement address at my graduation from the California Institute of Technology. It was a boiling day in June, and we graduates--all budding biologists and chemists and physicists--sprawled in folding chairs on the lawn, sweltering in our black gowns. Feynman told us that before we went public with new scientific results, we should consider every conceivable way we might be wrong. It was a tall order.

A recent case in point was the discovery, in March 2014, of evidence that purportedly confirmed the theory of inflation. According to the theory, proposed by physicists Alan Guth, Andrei Linde, and others in the early 1980s, the universe briefly inflated at an exponential rate when it was about one trillionth of a trillionth of a trillionth of a second old. It then slowed to adopt the more leisurely expansion predicted by the standard big-bang model. The theory of inflation naturally explained a number of observations not easily accounted for by the big-bang model, and it has been almost universally accepted by practicing cosmologists ever since.

But science places more value in predicting new phenomena than it does in explaining results already known. Years ago, the theory of inflation predicted a particular twisting pattern in the vibrations of the radio waves that pervade outer space, the so-called cosmic background radiation. Scientists studying three years’ worth of data from the BICEP2 observatory at the South Pole found such a telltale pattern last spring. The team involved more than 50 scientists and was led by John Kovac of the Harvard Smithsonian Center for Astrophysics. The story immediately went viral. In a press release titled “First Direct Evidence of Cosmic Inflation,” Kovac said, “Detecting this signal is one of the most important goals in cosmology today.” A YouTube video posted by Stanford University shows one of the team members excitedly telling Linde that they had found “the smoking gun of inflation,” after which they celebrate the success with a bottle of champagne, no doubt anticipating Nobel Prizes.

Then in January, another team of astronomers, using data from the European Union’s Planck satellite, announced that the twisting pattern was not actually caused by exotic processes at the birth of the universe. Instead, it was produced by galactic dust. It’s not that the Kovac group did sloppy work. Rather, the scientists had failed to follow Feynman’s advice. In their ardor to confirm what would have been one of the greatest scientific discoveries of the century, they had not sufficiently considered the possible competing effects of galactic dust--effects that other scientists had worried about at the time.

Passion is a double-edged sword, one that can bestow both fortune and misfortune upon those who wield it.

The history of science brims with similar cases, where eager scientists leaped to press too soon. One need only remember the 1970s-era anticancer drug Laetrile, which supposedly destroyed tumors; the reported discovery in 1975 of “magnetic monopoles” (magnets with either a south pole or a north pole but not both); and the reported achievement of cold fusion in 1989. Other scientists later disproved every one of these claims.

In fact, professional historians and philosophers of science know a dirty secret. The much-vaunted “scientific method” and its objective pursuit of truth often cannot be found in the work habits of individual scientists. It’s manifest only in the combined efforts of the scientific community, with researchers constantly testing and criticizing one another’s work. Individual scientists are driven by the same passions and biases and emotional attachments as non-scientists. Most try their best to be objective, but, as Francis Bacon, one of the fathers of the scientific method, said four centuries ago, “The human understanding is no dry light but receives infusions from the will and affections.”

The much-vaunted "scientific method" and its objective pursuit of truth often cannot be found in the work habits of individual scientists.

This year, in particular, it would be wise to keep Bacon's warning in mind. In March, the world's most powerful particle accelerator, the Large Hadron Collider (LHC), came back online after a two-year hiatus and an upgrade that doubled its energy. In 2012, the LHC helped scientists find the long-sought Higgs boson. This year, it could do the same for dark matter, a mysterious and still unobserved subatomic particle believed to make up about 27 percent of the universe. Elsewhere, physicists are mounting at least four major experiments to confirm the existence of dark energy, a similarly unobserved substance theorized to create a kind of negative gravity that causes space to expand at an accelerating rate. Astronomers are getting their first good looks at the comet 67P/Churyumov-Gerasimenko and the dwarf planets Pluto and Ceres, all of which could yield clues about the formation of our solar system. And the hundreds of biologists and neuroscientists involved in the Human Brain Project in the EU and the BRAIN Initiative in the U.S. will be investigating the riddles of brain function more deeply than ever before. Evidently, we may be in for another year of irrational exuberance.

And yet that may not be so bad. Exuberance carries its share of risks, certainly, but I would argue that it’s also essential to the enterprise of science. Without personal investment and passion, most scientists would not struggle with their research projects for months and years as they do. They would not stay up all night in their labs as they do. They would not endure the tedium and strain and constant possibility of failure or dead-end results. I remember well my days and nights working in astrophysics, thinking about my current research problem nearly every minute of the day, sometimes eating meals of peanut butter at my desk so as not to interrupt my feverish calculations. All my energy, my thoughts, even my personal identity and self-worth hung on those calculations.

Science would not proceed without such devotion. And there is the irony. Passion is a double-edged sword, one that can bestow both fortune and misfortune upon those who wield it. Passion is the stuff that drives us on, but it can also cloud our vision. The late physicist Joseph Weber argued for decades that he had observed gravi­tational waves with acoustic cylinders of his own making, and he adamantly defended those claims against overwhelming evidence to the contrary. Ultimately, that work was discredited, yet the concepts and equipment he developed serve as the basis for all gravitational wave detectors in use today.

We often make sharp distinctions between the sciences and the arts and humanities. Science aims at the external world of atoms and molecules, while the arts and humanities concern the internal world of emotions and sensibilities. Certainly, these distinctions are valuable as guiding principles, but in individual people, whether scientists or not, such neat separations do not occur. Nor in my view would they be desirable.

At its core, science is a human endeavor. Its strengths and flaws mirror our own. We should, of course, aspire to Feynman’s advice, to accept nothing but the truth. But we also need to accept human beings in their totality, both as scientists and humanists, as objective and subjective, as dispassionate and passionate, as travelers in this strange cosmos trying to make sense of our world and ourselves.

Alan Lightman is a physicist, novelist, essayist, and educator at the Massachusetts Institute of Technology and a finalist for the National Book Award.

This article was originally published in the May 2015 issue of Popular Science.