[Alan McDougall (OP)]

http://www.slate.com/articles/health_and_science/books/2012/10/samuel_arbesman_s_the_half_life_of_facts_reviewed_.html

A network scientist examines the lifespan of a fact.


It's an irony of modern life that the exponential spread of information has given rise to another exponential spread, of books about the exponential spread of information. We've got more facts than we ever had before, and so we've got more ruminations on how those facts affect us. Does Google make us stupid, or has it given us a deeper knowledge? Is there now so much to read and learn that we'll never master anything (a concern that dates back at least 800 years)? Are all these facts disposable, such that what we learn today will be obsolete tomorrow?

DANIEL ENGBER

Daniel Engber is a columnist for Slate.

The Harvard network scientist and pop theorist Samuel Arbesman stokes our fears of information on the cover of his recent book, The Half-Life of Facts: Why Everything We Know Has an Expiration Date. Watch out, that title says: The truth is melting! But the argument that Arbesman lays out (in a set of loosely connected anecdotes and essays) works to do the opposite. He uses math as a medication for this anxiety, to keep us calm in the face of shifting knowledge. His book works like a data-beta-blocker: By fitting fickle truths to models and equations, it promises a way to handle life's uncertainty and keep abreast of "the vibrations in the facts around us." In the end, though, the prescription runs afoul of a more fundamental ambiguity: What does it mean to call a fact a fact to start with?

Arbesman's book expands on a piece he wrote in 2010 for the Ideas section of the Boston Globe. That short essay, called "Warning: Your reality is out of date," laid out a theory of what Arbesman named the mesofact. "When people think of knowledge," he wrote, "they generally think of two sorts of facts."

One includes the data that should never change, like the atomic weight of hydrogen, while the other comprises all the tidbits that shift from day to day, like the closing price of the Dow Jones Industrial Average. Even in the stable camp, facts can mutate: An atom's weight, for example, varies depending on the isotope. But Arbesman is more interested in a third category of knowledge, one that's nestled between the other two in terms of how amenable it is to change. These are the facts that shift too slowly for us to notice, but not so slowly that they'll only matter to our children. "Mesofacts," he says, evolve within our lifetimes but often out of view.

Do facts become half-truths? (My Comment Alan)

[alancalverd]

There are indeed two sorts of facts. Those you are told by scientists, which you can check for yourself (repeatability being an important criterion in science) and those you are told by priests, politicians, philosophers, economists, and all the other professional parasites who infect the planet. The second type of fact cannot, of course, be checked and occupies part of a spectrum between guesses, wishes, halftruths and outright lies.

You can usually tell the difference by the qualifying context. Did the speaker say "don't take my word for it, look down the microscope and see if you agree", or did he say "all the experts agree...."? When projecting his fact into the future, did he say "therefore I expect...." or "obviously....."? And is the future "interesting" or "inevitably disastrous"?

Even the statement "an atom's weight varies, depending on the isotope" is a lie, i.e. not a scientific statement. The mass of an atom does not vary, but atoms of several different masses can have the same number of protons and electrons, hence very similar chemical properties, and thus be named as the same element. The only exception is hydrogen/deuterium/tritium whose significantly different atomic masses give rise to measurably different reaction rates. And of course the weight of an atom depends on the local gravitational field.

[evan_au]

At one time it was suggested that the number of scientific papers was doubling every 5 years.

So by the time you finish a 5-year degree, half of what you learned will be obsoleteor incomplete in some sense.

Life-long learning is the only way to stay moderately up-to-date.