While researching Too Big to Ignore: The Business Case for Big Data, it became pretty obvious to me pretty quickly that we don't know nearly as much as we think we do. As countless studies have shown, we're not very good at making decisions-and what we know today may not be true tomorrow.
Against this back drop, I read and thoroughly enjoyed The Half-life of Facts: Why Everything We Know Has an Expiration Date by Samuel Arbesman. It's a great read and I sat down with the author to talk about the book.
Why did you write the book?
Simply put, I wrote the book in order to explain how our current state of knowledge changes. We all know that facts are changing around us--from how we deal with nutrition to whether Pluto is a planet. That isn't particularly surprising. But for many people, when they see such examples, they either throw their hands up in despair at ever being able to keep abreast of all that's changing, or worse, begin to doubt the scientific enterprise and how it discovers new things.
I wanted to show that beneath all of the flux and seeming chaos of changing knowledge, there are rules to how facts grow and change, and that understanding how science works can help us to understand this. The metaphor of the half-life encapsulates this: we can't predict when a single radioactive atom is going to decay, but when you get a lot of atoms together, you can chart out a clear curve of decay, and even capture this in a single number: the half-life. The same kind of thinking is true with facts. I can't predict the discovery that will occur next, or which fact will be overturned in a week, but when looked at as a whole, knowledge obeys an order. And this order can be understood in the language of mathematics.
What myths do you hope to dispel?
I hope to dispel the myth that just because scientists learn new things, or overturn old ideas, that we are in a constant state of not knowing the truth. We must learn to distinguish between the work done at the frontier of knowledge--which is subject to flux--and that in the core, where we have a much better sense of the truth of the world around us. And even when knowledge does get overturned, it is part of coming ever-closer to an understanding of our surroundings.
Will facts continue to have half-lives?
Well, facts about the state of the world--such as how many billions of people there are on the planet, or the fastest computer speed--are always going to change. But there are some regularities behind these. In addition, scientific knowledge will continue to be overturned. Whether it's the refinement of our theories and measurements, or the rarer--but exciting--overturning of scientific models, we aren't near the end of science. And closer to the everyday, medical techniques, treatments, and cures, will continue to have half-lives, being overturned as we learn new things about ourselves and the world around us.
Favorite story from book?
There are a lot of really interesting stories I discovered about changing knowledge when writing The Half-Life of Facts. But one of the more bizarre examples is a story I tell to explore how bits of information, true or otherwise, spread from person to person. Once while perusing the reference book Dictionary of Theories, I chanced upon the entry about the dynamics of an asteroid. Within it was a discussion of the work of James Moriarty. But here's the thing: James Moriarty is Professor Moriarty, the nemesis of Sherlock Holmes. Despite his fictional status, I have discovered multiple references to Moriarty's scholarly work in books and articles, used as references for topics in mathematics and physics. This ability for fiction and reality to intermingle (and possibly confuse readers, though these references are often included as inside jokes) is fascinating, but also an indication that how knowledge spreads is a far more complicated process than we often realize.