FORTUNE — A photographer for Time, Life, and National Geographic, Rick Smolan says he relishes taking on the impossible. Decades ago he decided to try and capture life on the Australian continent in a day — so he sent dozens of photographers into the field for 24 hours, collecting their work into a single book and spawning the Day in the Life series. His latest project, The Human Face of Big Data, uses photographs, infographics, and even an app to attempt to both tell the story of how we use this astonishing glut of data and, for one day — October 2nd — take the temperature of humanity. Fortune spoke to Smolan about this project, excerpted in our latest issue.
How did you decide this — Big Data — was the project for you?
One of the nice things about living in Silicon Valley is that I end up at all these conferences and things, and I get to listen in on the zeitgeist. It was cyberspace once. About a year ago, Big Data was it. It was like one of those phrases you attached to things, and suddenly they glow.
At what point did you begin to think of this visually?
I was looking for metaphors, looking for something to latch onto. I started hearing this idea about how, with the growth of information technology, it was like watching the planet grow a nervous system. Suddenly all the pieces were coming together. I was hearing the same thing about all this data getting collected by all these devices, all of us carrying our very smart phones around all the time. And then I started thinking: How would you take photographs of it? It all sounded incredibly impossible.
So what kept you from giving up right then?
I actually wanted to understand it. I started approaching companies to see if any were willing to sponsor the project. I met dozens, but the only person that immediately understood what were trying to do was Jeremy Burton, EMC’s chief marketing officer. Like all my other projects, we maintained editorial independence.
In trying to understand it, were you thinking of how you’d structure the book?
Oh yes. Visually, the pictures fell into three categories. Some are just a cool story, but we had to send a photographer out to bring the story to life. There’s a story about tracking all the energy consumption in your house. How do you photograph a gadget in a new, and not boring, way? You have to get away from people sitting in front of a computer. You have to get a look at the digital signature.
Then there were pictures that were symbolic. You look at the pictures, the pictures are breathtaking, and they provide a filter for the narrative of the book. Finally, some of the pictures weren’t photographs at all, but infographics: How does Google use information?
You also, occasionally, turned to historic photos. Why was that?
It makes you think about data in such a fresh way. One of my favorite pages is a Time photo from the 1950s of the FBI filing system. I thought, that’s so cool, that’s the way it used to be done. Then I wondered, where does Julian Assange keep his data so people can’t hack it? I wonder if there’s a cover story with [J. Edgar] Hoover vs. Assange? It will be so interesting to see with the passage of time what he and Wikileaks represent.
Do you realize the FBI filing system from the 50s was much, more secure? How could you have stolen that data? It was on notecards. Now someone with a thumb drive, or remotely, can take the equivalent of millions of those notecards.
Now, the project doesn’t end with the book — there’s an app, a participatory element. Was that in the plan all along?
I love the idea of adding a new technology component to our books. My company, Against All Odds Productions, has done print on demand, we were the first to do a book with a CD-ROM in the early 1990s, we do custom covers. It’s always fun to do something new. I love this idea of collaborative crowdsourcing. We hope the app will be fun and compelling. It’s a week of collection. We have three mission control centers in Singapore, London, and New York City. Throughout the day, on October 2nd, we’ll have these TED-like talks from people at companies such as 23 and Me, Major League Baseball, FedEx (FDX), and real data scientists. We want to hear all about what everyone’s doing with data.
What will the app do?
We want it to help us measure the world and learn about it in the process. You can sign in through Facebook, but you can also sign in anonymously. We don’t want email addresses. All the data will be public, so scientists and researchers can study. We want to find out things like how fast the average New Yorker moves through her city vs. the average person in Shanghai.
Another pretty cool function is the app will find what we’re calling your “data doppelgänger.” Someone who is just like you but lives on the other side of the world. It’s not a dating service. You’ll never be able to talk to that person. But you’ll still know they are there.
We’re also doing a scaled-down version of this global project for students all over the world, using data to understand their communities, for one day, on November 8th.
The thing I’m probably most excited about, though, is we are collaborating with FedEx to deliver a copy of the book to 10,000 world leaders and CEOs: the most influential men and women on the planet. The more influential you are, the harder it is to get something to you. So it’s been very interesting to find, say, Richard Branson’s home address. Or figuring out how to make sure that, when you send a book to Hillary Clinton, it doesn’t just get lost in the mailroom.