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Descartes: arguably the 82nd most significant person in history (Image: Dumesnil, Pierre-Louis the Younger (1698-1781)/Bridgeman Art Library)

Which historical figures command most attention? A computer scientist and a Google engineer have devised an algorithm to rank them all in Who鈥檚 Bigger?

ISAAC NEWTON, Jesus Christ, Alexander the Great: who should we rate as most significant? And how does Elvis Presley fare next to Ren茅 Descartes?

Posing such questions would once have been laughable. Not any more. Now we can make these comparisons as rationally as whether Twitter is a better investment than Apple. This is the thrust of Who鈥檚 Bigger? Where historical figures really rank by Steven Skiena, a computer scientist at the State University of New York, and Charles Ward, a software engineer at Google.

They approach world history with the tools of quantitative analysis favoured by Wall Street traders and baseball managers, distinguishing from the outset traditional history from their interest, historiography 鈥� the study of history as a discipline. They try to measure which historical figures command our attention most powerfully and persistently. This is people as memes, so the contest of Elvis versus Descartes becomes a question of whether 鈥渁in鈥檛 nothin鈥� but a hound dog鈥� is more viral than 鈥渃ogito ergo sum鈥�.

Evidently it is, since Elvis ranks 69 to Descartes鈥檚 82 on their list of history鈥檚 100 most significant people. Skiena and Ward derive this list from a ranking algorithm they created, inspired by Google鈥檚 PageRank system, which looks at how many links to other Wikipedia pages there are on a person鈥檚 own page. This measure of gravitas is combined with statistics on the entry鈥檚 length, revision history and monthly hits to achieve what the authors call celebrity. It is then adjusted for 鈥渞eputational decay鈥�, an estimate of how fame falls when someone passes out of living memory.

Each of the 843,790 people who had their own Wikipedia page on 11 October 2010 when the model was run is now reduced to a number, from Jesus (1) to aikido master Sagusa Ryusei (843,790).

But it鈥檚 one thing to rate Jesus higher than Ryusei, another to rank Elvis above Descartes. The authors try to verify their algorithm by taking people from narrow categories (US presidents, baseball stars) and comparing their ranking to expert/popular ratings, or to game statistics. Examining dozens of lists in nine categories, they found an average correlation of 0.544 between their rankings and those on published lists, significantly higher than the 0.49 average correlation between all published lists in a category.

For example, here鈥檚 the ranking for eminent scientists: 12 Darwin; 19 Einstein; 21 Newton; 31 Linnaeus; 44 Freud; 49 Galileo; 74 Copernicus; 81 Bacon; 103 Ptolemy; 112 Pasteur; 156 Kepler; 175 Faraday; 216 Hooke; 250 Mendel; 276 Lavoisier.

Even so, what do rankings mean when there is no real connection between those being compared? While Skiena and Ward鈥檚 claim that their analysis provides a new way to interpret the past seems promising, they rarely offer an observation that isn鈥檛 obvious or wildly speculative. For example, they plot autograph prices against historical significance to calculate Jesus鈥檚 signature should be worth $5,780,960, but admit that a lack of data on ancient autographs makes matters very tricky.

聯The authors plot autograph prices against historical significance: Jesus鈥檚 should be worth $5,780,960聰

This is all fun: reputational face-offs are great entertainment. And, shrewdly, Skiena and Ward have an app. More seriously, historians will put quantitative analysis to good use 鈥� and their model may help historiographers grapple with Wikipedia.

But there is a dark underside, revealed when the authors offer their rankings as guidelines for textbooks. When it comes to educating under-11s, Skiena and Ward propose favouring higher rated figures over lower, and banish those who rank over 5000 to the 鈥渄ead zone鈥�.

Skiena and Ward鈥檚 techniques are new, but their 鈥済reat man鈥� view of history is ultimately old-fashioned. Importance is a matter of context.

This article appeared in print under the headline 鈥淧eople as memes鈥�