Many of the most important moments in our lives rely on the judgment of others. We expect doctors to diagnose our illnesses correctly, and judges to hand out rulings fairly. But there’s a massive flaw in human judgment that we’re just beginning to understand, and it’s called “noise.” In a new book, former University of Chicago law professor Cass Sunstein along with his co-authors, Daniel Kahneman and Olivier Sibony, take us through the literature on noise, explains how it shows up in our world and what we can do to fight it. From misdiagnoses to unequal treatment in courtrooms, noise is the “silent killer” we didn’t even know was there.