Activities in 2008-2009

From the Report for Academic Year 2008-2009
of the Institute for Advanced Study

PIET HUT's activities included both his astrophysics research and his responsibilities as the Head of the Program of Interdisciplinary Studies. The latter program had twenty-one visitors, with durations of their visits ranging from days to months, in fields including physics, mathematics, biology, computational science, artificial intelligence, cognitive science, philosophy, history, education, law, library science and media.

During the year, Prof. Hut, together with colleague Caroline Bynum from the School of Historical Studies, organized a series of After-Hour Conversations, which were held at IAS in Harry's Bar, two or three times a week for a period of two months during each semester. Each gettogether had a more formal part lasting thirty minutes, starting with a ten-minute talk by a speaker and followed by a twenty-minute period of questions. In addition, many participants would continue informal conversations afterward. These activities were widely seen as an effective way to lower the threshold for inter-School communication at IAS.

Prof. Hut's main research focus this year continued to be his exploration of virtual worlds, especially Second Life, currently the largest non-game 3D on-line virtual world, with a continued presence in-world of well over 50,000 residents at any given time. In the spring of 2008, he brought into Second Life an organization that he had founded a year earlier, the Meta Institute for Computational Astrophysics (MICA; During the first year of its operation, MICA developed into a kind of virtual astronomy department, with regular colloquia for professional astrophysicsts as well as outreach events, including popular talks about astronomy as well as "ask an astronomer" sessions in which amateur astronomers were invited to engage in questions with the professionals present.

In addition to these weekly events, MICA organized a workshop at Caltech, where the people present there in Real Life were joined by those present in Second Life. This was a fascinating so-called "mixed reality" event combining the advantage of face-to-face interactions between the local participants with ease of access of remote participants through the use of virtual world technology.

A whole other dimension to doing science in virtual worlds was added in the summer of 2008, when Hut and co-workers used an open-source version of Second Life, called OpenSim, to perform N-body simulations. Through a relatively small change in the physics engine, the software module that governs gravity and other physical effects, they were able to replace simple constant-force gravity on the surface of the Earth by the Newtonian inverse-square force law. As a result, creating a bunch of stars and letting them loose in the virtual sky resulted in a realistic stellar dynamics simulation. In this way, it was straightforward to turn a virtual world into a virtual astrophysical laboratory.

Another institute that was co-founded by Hut, Kira (, was brought into Second Life in the fall of 2008. Kira was founded twelve years ago as a broadly interdisciplinary institute by faculty members from Stanford University, Princeton University, IAS and elsewhere, as a forum to discuss the nature of scientific knowledge and to compare that with other ways of knowing, from philosophy and art to various contemplative traditions. The move into a virtual world was very successful. Whereas Kira had offered one summer school and several weekend workshops, yearly, in Real Life, the virtual Kira Institute soon offered half a dozen events every day in Second Life. In this way, Kira has become one of the most vibrant organizations in Second Life.