Arbesman, a senior scholar at the Kaufmann Foundation and an expert in scientometrics, looks at how facts are made and remade in the modern world. And since fact-making is speeding up, he worries that most of us don’t keep up to date and base our decisions on facts we dimly remember from school and university classes that turn out to be wrong.
Since scientific knowledge is still growing by a factor of ten every 50 years, it should not be surprising that lots of facts people learned in school and universities have been overturned and are now out of date. But at what rate do former facts disappear? Arbesman applies the concept of half-life, the time required for half the atoms of a given amount of a radioactive substance to disintegrate, to the dissolution of facts. For example, the half-life of the radioactive isotope strontium-90 is just over 29 years. 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,” reported the researchers.
Arbesman also delves into what he calls “hidden public knowledge.” Consider again that nearly 850,000 new articles dealing with biomedical research were published in 2009; lots of true information will be overlooked in that deluge.
People also cling to selected “facts” as a way to justify their beliefs about how the world works. Arbesman notes, “We persist in only adding facts to our personal store of knowledge that jibe with what we already know, rather than assimilate new facts irrespective of how they fit into our worldview.” All too true; confirmation bias is everywhere.
Toward the end, Arbesman suggests that eventually “exponential knowledge growth cannot continue forever.” Among the reasons he gives for the slow-down is that current growth rates imply that everyone on the planet would one day be a scientist. The 2010 study in Scientometrics mentioned above also mused about the growth rate in the number of scientists and offered a conjecture “that the borderline between science and other endeavors in the modern, global society will become more and more blurred.”