Weekly Colloquium at the SETI Institute

Fullerenes are a class of large and remarkably stable carbonaceous molecules in the shape of a hollow sphere or ellipsoid; the best known member of the class is the archetypical “buckminsterfullerene” C60 that resembles a soccer ball (and is therefore often called “buckyball”). Dr. Cami and colleagues have recently discovered the unmistakable spectral signatures of the fullerene species C60 and C70 in Spitzer observations of a young planetary nebula, and these are now the largest molecules known to exist in space. Since this discovery, fullerenes have been reported in a wide variety of astronomical objects at abundances of typically 0.1—1.5% of the cosmic carbon. They are formed in carbon-rich evolved stars, survive in the interstellar medium and are also detected in the disks surrounding young stars. Fullerenes have many interesting properties and could play a unique role in the physics and chemistry of the interstellar medium.

In this talk, Dr. Cami will give an overview of what we have learned so far from observational analyses, with a special focus on the surprising aspects that have challenged our understanding of some of the physics and chemistry involved – in particular about the formation and the state of fullerenes in space.

Time travel makes great science fiction, but can it really be done? Travel into the future is already a reality, but visiting the past is a much tougher proposition, and may require fantastic resources such as a wormhole in space. Nevertheless, if going back in time is allowed, even in principle, then what about all those paradoxes that make time travel stories so intriguing?

Paul Davies is a physicist, cosmologist and astrobiologist at Arizona State University, where is Director of the Beyond Center for Fundamental Concepts in Science. He is the author of many books, including "How to Build a Time Machine" and, most recently, "The Eerie Silence: are we alone in the universe?"

The current feeds of the antennas in the Allen Telescope Array are somewhat unusual and provide wide bandwidth and good sensitivity.  We have recently developed an upgrade to the feed which has even more bandwidth and, equally important, substantially better sensitivity.  The new sensitivity is about as good as can be achieved.  We describe the steps to the upgrade and then lay out new science that is enabled by it, including SETI and the structure of both the nearby and distant universe.