Major tragedies such as plane crashes can capture the world’s attention for months or even years as we pore over the facts to figure out what went wrong, but how long will we remember these events before they fade into obscurity? Based on a study of Wikipedia traffic data, several scientists believe they have found the answer: about 45 years.

According to the study, which was published in the journal Science Advances, Internet traffic can tell us a lot about our collective memory.

“On the one hand, the Internet has had strong impacts on memory and the processes of remembering and forgetting,” the team says in the paper, “and on the other hand, it has converted collective memory into an observable phenomenon that can be tracked and measured online at scale.”

Wikipedia has become a go-to source of information for many people, and the researchers said that current events can often trigger visits to articles for similar events that had occurred in the past, a process they call “view flow.” Looking specifically at articles related to plane crashes, the researchers found that recent crashes trigger more article views for previous crashes.

View flow is stronger for more recent events, but the effect grows weaker the further back you go. In other words, many users might delve into crashes that occurred in the last few years, but few are interested in looking back much further than that. The researchers measured the strength of view flow between a large number of articles related to plane crashes and determined that those events stay in our memory for roughly 45 years before they are more or less forgotten.

There are a few factors that could make certain events stick in the public mind longer, including both high death counts and no deaths at all. The research team was also quick to note that Internet traffic may not paint a completely foolproof picture of collective memory, and the 45-year number could be skewed by a few different factors.

“This 45-year limit might reflect the fact that people who were adults at the time of the accident might not use Wikipedia,” the researchers said, “or may have died in the interim or simply may have forgotten about the accident during that time interval, such that only written records are left in the end.”

You can read the full paper here.

Photo: wilco737 Malaysia Airlines Boeing 747-400 at LHR (9M-MPJ) via photopin (license)