A 2010 study in the journal Scientometrics, looking at data between 1907 and 2007, concurred: The “overall growth rate for science still has been at least 4.7 percent per year.”
Since knowledge is still growing at an impressively rapid pace, it should not be surprising that many facts people learned in school have been overturned and are now out of date. But at what rate do former facts disappear? […]
Applying the concept of half-life to facts, Arbesman cites research that looked into the decay in the truth of clinical knowledge about cirrhosis and hepatitis. “The half-life of truth was 45 years,” he found.
In other words, half of what physicians thought they knew about liver diseases was wrong or obsolete 45 years later. Similarly, ordinary people’s brains are cluttered with outdated lists of things, such as the 10 biggest cities in the United States.