Physics Department Colloquium

Abstract: Rubble pile asteroids are thought to form in the aftermath of cataclysmic collisions between proto-planets. The details of how the detritus from such collisions reaccumulate to form these bodies are not well understood, yet can play a fundamental role in the subsequent evolution of these bodies in the solar system. Simple items such as how particle sizes and porosity is distributed within a body can have a significant influence on how they subsequently evolve.

Abstract: The solar corona is the hot and ionized outer atmosphere of the Sun.  It traces out the complex solar magnetic field and expands into interplanetary space as the supersonic solar wind.  In 1958, Eugene Parker theorized that the presence of a million-degree corona necessarily requires the outward acceleration of a wind.  However, despite many years of exploration of both phenomena, we still do not have a complete understanding of the processes that heat the coronal plasma to its bizarrely high temperatures.

Abstract: Over the last twenty years, physicists have learned to manipulate individual quantum objects: atoms, ions, molecules, quantum circuits, electronic spins... It is now possible to build "atom by atom" a synthetic quantum matter. By controlling the interactions between atoms, one can study the properties of these elementary many-body systems: quantum magnetism, transport of excitations, superconductivity...

Abstract: 1D gases with point contact interactions are special because they are integrable many-body systems, which means that they have many extra conserved quantities, beyond the usual few (energy, momentum, etc.). I will explain how we make bundles of 1D Bose gases in the lab, the various ways we excite them out of equilibrium, and how we use them as model systems for studying quantum dynamics.

Abstract: Neutrinos are enigmatic particles. Their properties are rather basic and yet so bizarre and surprising that at times we hardly believe them. We barely notice their presence, and yet they are everywhere and are essential to things as glaring as the sun’s energy production. The minuscule but non-zero mass of a neutrino, nearly a million times smaller than the electron (the next lightest particle), has enormous consequences for our understanding of these particles and their role in shaping the universe.

Abstract: We utilize transport systems daily to commute, e.g. via road networks, or bring energy to our houses through the power grid. Our body needs transport networks, such as the lymphatic, arterial or venous system, to distribute nutrients and remove waste. If the transported quantity is information, for example carried by an electrical signal, then even the internet and the brain can be thought of as members of this broad class of webs.

Abstract: Fusion energy is a promising technology for producing clean, limitless, zero-carbon energy. Recently, there has been a paradigm shift where today, privately funded research dominates over the historic government-funded fusion program. Private research and development paths to fusion have very short timelines, and some future milestones appear speculative. I will discuss plasma and nuclear physics constraints that experiments will face as they progress toward the fusion goal.

Abstract:

Coffee, tea and cookies will be available in G1B31 (across from G1B20) from 3:30–3:50 p.m.

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