technologyreview | In July, Joseph Giaime, a physics professor at Louisiana State University and Caltech, gave me a tour of one of the most complex science experiments in the world. He did it via Zoom on his iPad. He showed me a control room of LIGO, a large physics collaboration based in Louisiana and Washington state. In 2015, LIGO was the first project to directly detect gravitational waves, created by the collision of two black holes 1.3 billion light-years away.
About 30 large monitors displayed various aspects of LIGO’s status. The system monitors tens of thousands of data channels in real time. Video screens portrayed light scattering off optics, and data charts depicted instrument vibrations from seismic activity and human movement.
I was visiting this complicated operation, on which hundreds of specialists in discrete scientific subfields work together, to try to answer a seemingly simple question: What does it really mean to know anything? How well can we understand the world when so much of our knowledge relies on evidence and argument provided by others?
The question matters not only to scientists. Many other fields are becoming more complex, and we have access to far more information and informed opinions than ever before. Yet at the same time, increasing political polarization and misinformation are making it hard to know whom or what to trust. Medical advances, political discourse, management practice, and a good deal of daily life all ride on how we evaluate and distribute knowledge.
We overstate enormously the individual’s ability to amass knowledge, and understate society’s role in possessing it. You may know that diesel fuel is bad for gas engines and that plants use photosynthesis, but can you define diesel or explain photosynthesis, let alone prove photosynthesis happens? Knowledge, as I came to recognize while researching this article, depends as much on trust and relationships as it does on textbooks and observations.
Thirty-five years ago, the philosopher John Hardwig published a paper on what he called “epistemic dependence,” our reliance on others’ knowledge. The paper—well-cited in some academic circles but largely unknown elsewhere—only grows in relevance as society and knowledge become more complex.
One common definition of knowledge is “justified true belief”—facts you can support with data and logic. As individuals, though, we rarely have the time or skills to justify our own beliefs. So what do we really mean when we say we know something? Hardwig posed a dilemma: Either much of our knowledge can be held only by a collective, not an individual, or individuals can “know” things they don’t really understand. (He chose the second option.)
