Lorimer and Narkovic had uncovered the first fast radio burst, or FRB. It was a total surprise to them; the idea of radio wave bursts had been abandoned after scientists in the ’70s and ’80s failed to locate such signals. Only a handful of them (11 at last count) have been observed since their discovery nine years ago, and they remain unique. Many astronomers think they come from outside the galaxy, but beyond that, their origins remain mysterious. As novel as FRBs are, however, they are just the latest example of a sporadic but always exciting moment in science: an unexpected discovery of an anomaly in the expected data.
Although each unusual scientific discovery is unique, different disciplines of science process these anomalies similarly. The physicist and philosopher of science Thomas Kuhn first advocated the importance of such unexpected discoveries in the 1960s. Scientific progress is not a linear development of accepted theories, he argued, but instead relies on such anomalous discoveries to move the field forward. When enough accumulate from experiments, a field will enter a period of crisis, which often leads to a fundamentally new understanding of the field, known as a paradigm shift. Science is filled with examples of paradigm shifts throughout its history, such as the switch from Newtonian to Einsteinian physics, the rise of evolution to account for the variety of life and the acceptance of plate tectonics to explain the movement of continents over time.
In astronomy, paradigm shifts typically come from an unexpected signal in the sky. Steady pulses in the 1960s yielded the unexpected discovery of pulsars — the city-size neutron stars that Lorimer sought when he stumbled upon FRBs. Similarly, gamma ray bursts can originate from among the most violent events in the universe, such as the collapse of a massive star, but they were only serendipitously discovered by researchers monitoring nuclear proliferation on Earth during the Cold War.
Kuhn revolutionized how scientific anomalies are viewed today, but it’s still not so simple. “Most historians and philosophers of science, although they like the thrust [of Kuhn’s argument], don’t buy it all,” says Alan Rocke, a science historian at Case Western Reserve University in Cleveland. “There are still many disagreements about the details.” In reality, history is far messier. Some paradigm shifts take a long time before a theoretical framework emerges, and sometimes anomalies lie dormant for decades or even centuries before being accepted and changing the course of science. Critical scholars argue that a Kuhnian world defined by sudden shifts is too simplistic, and that in reality things play out differently under different circumstances.