General Sessions & Public Talks

The 2006 Cosmology Prize of the Peter Gruber Foundation was awarded to John Mather and the COBE team during the Opening Ceremony of the General Assembly.

"I was in the first generation of humans that could actually do a search [for extraterrestrial intelligence] to try to answer the ancient "Are we alone?" question. For millennia, humans had just been asking the priests and philosophers what they believed." -- Jill Tarter

The Sun's magnetic field is produced throughout the solar interior; it emerges and is dispersed by surface and subsurface flows, and then expands above the surface to dominate the structure of the corona. To resolve the effects of the magnetic field it is necessary to image the interior and measure its rotation and flow systems; track the responses of the magnetic fields to flows in the surface; and to follow the evolution of structures in the corona. Because the Sun is dynamic both high spatial and temporal resolution are essential. Because the Sun's magnetic field effects encompass the entire spherical exterior, the entire surface and outer atmosphere must be mapped. And because the magnetic field is cyclic high-resolution observations must be maintained over multiple cycles.

This talk will illustrate solar phenomena with a sampling of the highest resolution images and movies of the photosphere, chromosphere, and corona. Many of the observations are both strikingly beautiful and surprising in their complexity. Surprising observations are the reason science is so exciting. Each new surprise drives new approaches, insights, and understanding. It is not discouraging that many complex interactions are occurring in the Sun it is exciting, challenging, and important to all of physics and astrophysics.

Many similar phenomena occur in astrophysical systems with spatial and mass scales different by many orders of magnitudes. In this talk I will summarize briefly these phenomena and possible physical mechanisms responsible for them. I will emphasize the importance of using the Sun as an astrophysical laboratory in studying some of these physical processes, especially the roles magnetic field plays in them; it is quite likely that magnetic reconnections dominate the fundamental energy release processes in all these systems. As a case study, I will show that X-ray light curves from solar flares, black hole binaries and gamma-ray bursts exhibit a common scaling law of non-linear dynamical property, over a dynamical range of many orders of magnitudes in intensities, in support of self-organized criticality mechanisms operating in their energy release processes.

The ongoing work on an IAU Resolution to scientifically define the meaning of the concept "planet" is of particular interest to the public. The IAU is the arbiter of planetary and satellite nomenclature since its inception in 1919. The boundary between planets and other solar system objects has never been defined and the recent discoveries of new objects in the solar system has made it necessary for the IAU to address this issue. The decision process and a draft Resolution for the Definition of a Planet will be published in the conference newspaper during the first week of the General Assembly.

Evidence has been accumulating for several decades that quasars, the most luminous objects in the Universe, are powered by accretion of matter onto massive black holes. I will discuss recent observations, employing adaptive optics imaging and spectroscopy on large ground-based telescopes that prove the existence of such a massive black hole in the center of our Milky Way, beyond any reasonable doubt. These observations also indicate that the Galactic Center black hole may be rotating rapidly. The central black hole is surrounded by a cluster of young massive stars, partly arranged in two, rotating disks. I discuss possible explanations for this "paradox of youth".