Woodruff T. Sullivan III—”Woody” for short—is a professor emeritus of astronomy at the University of Washington and co-founder of its astrobiology program. Here, he answers questions about the search for life beyond Earth, his plan to write a historical biography, and “the world’s first working sundial tattoo.”
Q: Would you describe your recent work with Adam Frank? It was covered by the New York Times under the headline, “Yes, there have been aliens.”
A: Well, scientists don’t like to use the term “aliens,” but that is a decent summary. In SETI—the search for extraterrestrial intelligence—one normally thinks about the actual problem of communication. And so you want to know how many are simultaneously existing.
We are saying that the Kepler mission, which has discovered so many exoplanets around other stars, allowed us to nail down several factors in the Drake Equation so that we could ask a different question: how many technological species like us have ever existed. We now can reliably estimate, for example, that in our Milky Way alone there are about 60 billion habitable planets.
It’s a philosophical thing to be concerned about how many past civilizations have occurred. You could think of it as a sort of cosmic archaeology. If you could travel around to planets not just in our own galaxy but in other galaxies—like an archaeologist goes around the world looking for evidence—we’re saying that it seems likely that you’d find evidence of these guys all over. And wouldn’t that be interesting?
We can now estimate how many habitable planets there are in the universe. But we don’t know, given a habitable planet, how often life begins and evolves to technology. Now if you want to posit that there’s never been a second such civilization in our entire universe, how pessimistic must you be? The answer is that you have to think that, given a habitable planet, the odds of a technological species emerging are worse than one chance in 10 billion trillion. That’s only one chance in 10,000,000,000,000,000,000,000!
This shows the degree of pessimism that you must have to say that we are unique over the entire 13 billion year history of the universe.
Q: Is there more work ahead for you and physicist and astronomer Adam Frank?
A: No, we’re still talking but I am not looking to do any more research on that. He will continue with his modeling work, which uses mathematical models to ask what ways we can imagine technological civilizations changing over millions of years.
Q: You are writing a biography of astronomer William Herschel (1738-1822). Why a biography, and why Herschel?
A: I’ve done much research and teaching in the history of astronomy over the decades, but never a biography, so that’s part of the fascination, to do something new. And Herschel has so many aspects—he was certainly one of a handful of the greatest observers of all time—discovered the planet Uranus, mapped out the Milky Way, discovered infrared radiation, and on and on.
He was a musician until he was age 40, but not just a player; he composed 20 symphonies and concertos and so forth. There have been many biographies of Herschel, even in the last 10 years, but they all focus on the astronomy and give half a chapter to the music. I’m not going to make that mistake. I’m collaborating with a musicologist who was a physics undergraduate. We are just beginning. And the key thing is, can we find connections between his science and his music and the way he thought about music and composing?
Another aspect is the technology—when he flipped to being an astronomer, Herschel learned how to make telescopes. And these were the world’s largest telescopes, mirrors made out of polished metal; you couldn’t make large glass mirrors in that era. His largest was 4 feet in diameter. He had a foundry in his basement! All self taught—just an amazing guy.
Yet another aspect is his interest in extraterrestrial life. He was convinced that all the planets were inhabited by intelligent beings—and even the sun.
Q: The sun as well?
A: The sun as well, which is why everyone goes ho ho ho! But, it was a very rational thing—the sun was a cold solid with a hot upper atmosphere—just the grandest of all the inhabited planets.
Q: Let’s move to your great interest in sundials—you have created or consulted on the design of many, even including one on the Mars Rovers. What sparked that interest, and when?
A: My sundial interest began very specifically in 1991. I got interested because three years before we moved in to the new Physics-Astronomy Building in 1994, the architects asked, what do you want? I’m thinking of my interest in history of science and art and design, so I casually said, “A sundial would be nice.” Since then, it’s hard to believe—like getting married—that there’s a phase in my life before that.
Q: Any sundial projects now underway?
A: I am working with the University of California, San Diego, and a Seattle architect, for a sundial that’s going up on a new building there this winter. It’s a wall dial, but a different design in many ways than the UW one. It will be 50 feet above the ground with a very asymmetric design.
That’s my current public sundial project. Then there is the sundial tattoo, which I call a private sundial project.
Q: A sundial tattoo? What’s the story behind that?
This started with a paleontologist graduate student in the astrobiology program. She likes sundials and we got talking and over the last couple of years we designed it. The idea was for her to have it, but she now has her degree and has since left town.
Meanwhile I said to myself, dammit – that would be pretty neat. In April I gave a talk to the British Sundial Society about the technical details and showed the decal I’d made for my inner forearm. I’m going to write it up for their publication. The world’s first working sundial tattoo!
Q: Will you get the sundial tattoo decal permanently inked?
A: My daughter asks, “Are you going to want it five years from now?” But it would be on the inside of my arm, not obvious. I’m seriously thinking about it, but haven’t made the final decision—I already have the required bracelet.
Q: A cliché question but: Is there a discovery you wish you had made that didn’t happen—a “one that got away”?
A: (Laughs.) I think I have been very fortunate in being able to work on things I found satisfying. I do also want to write a book called “Astronomy and Culture,” looking at the many aspects of how astronomy bears on the broader culture. I’ve written a couple of chapters.
One other thing—and it’s much larger than me—is that I hope, before I “shuffle off this mortal coil,” that we do find strong evidence for extraterrestrial life. Microbial life is the most likely.
If we found life somewhere down deep on Mars, should we dig it up and study it? Or protect the planet as is, on the theory that we are the invading “virus”?
A: There are different points of view even among scientists—many are gung-ho to terraform Mars—turn it