Carl Zimmer's newest book — "Science Ink: Tattoos of the Science Obsessed" — is a little different from his previous texts, which have included explorations into some pretty heavy scientific topics, from "Microcosm: E coli and the New Science of Life," to "Evolution, the Triumph of an Idea" and more.

Aside from authoring books, the prolific writer heads up the award-winning science blog on Discover Magazine's website called The Loom. That his most recent book is a gorgeous images-and-essays collection of the tattoos of scientists is a bit of a (pleasant) surprise. I interviewed Carl about how the project came about, and what he learned from this fascinating combination of science and art.

MNN: What was the inspiration for this book? It's kind of an unusual topic, no?
Carl Zimmer: It just seemed to happen almost as if it had a mind of its own. Three years ago, I noticed a neuroscientist I know had a DNA tattoo. He explained how he had encoded his wife's initials in the sequence. I was so intrigued that I took a picture and posted it on my blog. Soon I was buried in a flood of emails from scientists with tattoos of their own. I posted pictures on my blog, and eventually there were so many that I decided the time had come for a book.

Were you surprised by how many scientists had tattoos related to their areas of study?
I was very surprised. "Science Ink" ended up with tattoos from just about every discipline I can imagine — from linguistics to astronomy to chemistry to engineering. And each one had a deep, precise meaning to the scientist in question.

How long did it take to gather the tattoos and the stories? Did you have more than you needed or was it hard to find enough?
It took about a year to bring everything together for the book. First, the book designers and I had to let people know we were starting the project and ask for high-resolution photographs. We got a huge number of pictures in response, and in the end we selected about 300 images for the book. Then it came time for me to write the captions, which I approached as miniature essays. It took a lot of research to write the text — I communicated with scientists to get the stories behind the tattoos and did my own reading to learn about everything from Central Asian mummies to quantum physics.

What is your favorite or the most unusual or touching science tattoo story you came across?
There's one tattoo from a neuroscientist named Lindsay Reece that seems ordinary at first. It's a neuron on her foot. You might think this was an obvious, even banal choice. But it's not just any neuron. It's the kind that we use to send commands to our muscles. And when people get Lou Gehrig's disease (ALS), it's the type of neuron that dies. Reece's father died of ALS when she was 18, and that experience made her determined to become a neuroscientist.

Which discipline is the most tattooed? The least?
I don't have hard numbers, but there sure are a lot of people with DNA tattoos. I can't blame them, though. It's a beautiful molecule.