At the 2014 World Science Festival, WNYC radio journalist John Hockenberry compared searching for alien life to searching for and settling into a new home: You need a real estate agent (an astronomer to find the right planet), an interior decorator (a planetary scientist to assess whether the environment is hospitable to life), a chef to check if there are the right ingredients in the kitchen (a biochemist), and an accountant to juggle all the numbers and make sure you’re looking in the right neighborhood (a physicist or computer scientist). Thankfully, the Festival panel Alien Life: Will We Know It When We See It? had all those essential ingredients in place: Harvard astronomer Dimitar Sasselov, MIT planetary scientist Sara Seager, Howard Hughes Medical Institute geneticist and biochemist Jack Szostak, and Arizona State University physicist Paul Davies. Hockenberry, who moderated the panel, asked the team to rate just how close we might be to discovering extraterrestrials.

If aliens landed in the White House Rose Garden tomorrow, they’d have some explaining to do…and the person they’re most likely to try explaining it to is Paul Davies, chair of SETI’s Post-Detection Task Group since 2005. As we discover more and more Earth-like planets (including the celebrated Kepler 186f, the first Earth-size exoplanet found in the so-called “habitable zone” around its star) bring questions about the origins of life newly into the media forefront, we asked Paul to elaborate on the odds of finding life out there, what forms it might take, and the one question he’d ask the aliens.

Imagine driving across the United States without a map or GPS. How would you do it? How would you know where you are and how far you had to go? As impossible as this feat seems, millions of birds perform it every year. Traversing thousands of miles on annual migrations, Arctic terns, bar-tailed godwits, and ruby-throated hummingbirds seem to know exactly where they are going, yet for years scientists had no idea how they did it. One physicist, Klaus Schulten, thought one explanation might be that the birds could sense the Earth’s magnetic fields, perhaps using magnetite molecules in their eyes. But no one knew how that was possible. Recent research may provide a clue. Scientists now have evidence suggesting that at least some birds use quantum mechanics, the weird rules that govern the behavior of the microscopic world. A 2004 experiment involving robins showed that an extremely weak magnetic field could throw off the birds’ navigation abilities, an effect that made no sense if magnetite molecules provided the guidance, but fit perfectly with a model involving quantum entanglement, a subatomic process that allows widely separated objects to influence each other. In this model, when a photon of light enters …