Changing Planet

Underwater Caves, Outer Space, and the Fear Factor

What does a cave diver who dives into dark, narrow underwater caverns with only a thin cable connecting him to the surface have in common with an astrophysicist who does his exploration sitting at a computer monitor his bathrobe?  The unexpected answer, from Nobel Laureate in Physics Adam Riess: fear.

Adam Riess, Nobel Laureate in Physics. Photo by Will Kirk.

“We’re both scared,” said Riess, the director of the Space Telescope Science Institute at Johns Hopkins University, while sharing a stage at National Geographic headquarters Wednesday night with environmental anthropologist and Nat Geo Explorer of the Year 2011 Kenny Broad, who has explored the flooded caves, or “blue holes” of the Bahamas.  “Kenny’s probably scared cause he could die… I’m just scared that I’ll embarrass myself.”

For Kenny, the fear is immediate and existential: one false move or bad decision in a blue hole can quickly prove fatal.  Reiss’ moment of fear came when he realized that his calculations were showing something thought to be impossible by most of his fellow physicists: not only is the universe still expanding, as predicted by the Big Bang model, but it’s speeding up, rather than slowing down as the model also predicted.  “[Scientists] make mistakes all the time.  They run out of their office going ‘wow, something really weird’s going on,’ but most of the time it’s a bug or it’s a mistake or a minus sign in the wrong place.  I was just very afraid for many weeks and months as I kept analyzing this that I’d made a mistake and it would be a stupid mistake.”  Instead, observations by other scientists confirmed Reiss’ finding, which was eventually declared a “breakthrough of the year” by Science magazine.

NG Explorer Kenny Broad. Photo courtesy NGS.

On stage along with Broad, Riess and moderater John Bredar, the Senior Executive Producer for National Geographic Specials, were a wetsuit and a pair of fuzzy slippers,  symbolizing the very different, but equally important, styles of exploration exemplified by diver and physicist.  Our Big Idea series uncovers not just the contrasts but the surprising connections between the work of Nat Geo explorers and Nobel laureates, both of whom are using their distinctive tools and techniques to probe the unknown, and showing that the spirit of exploration is alive and well in the 21st century.

Join us at National Geographic headquarters in Washington, D.C. for our next two conversations between Nat Geo explorers and Nobel Laureates, on November 30  and December 11.

About the Blog

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society’s conversation platform Voices.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service.

Voices director: David Braun (

Social Media