Stoney’s British Pub
3007 Concord Pike
University of Delaware
“The Sun to the Earth and Beyond: Dynamics of the Plasma State of Matter”
The plasma state represents a fourth state of matter that may not be as familiar as solids, liquids and ordinary gases, but actually pervades most of the universe. From magnetars and accretion disks, to molecular clouds and planetary nebulae, the dynamics of matter in the plasma state determines much of what we see in the cosmos. Closer to home, in the solar system, plasma dynamics in the sun’s corona generates a very fast solar wind that blows out a huge bubble in the interstellar gas, creating the plasma heliosphere. Plasma dynamics controls the energetic particle and magnetic environment within this bubble, where our planet Earth resides.
After reviewing some general features of cosmic plasmas, this talk will focus on three challenging problems in heliospheric plasma physics. First we will discuss the peculiar way in which the coronal plasma is heated, thus generating the solar wind and creating the heliosphere. Second we will discuss how turbulent motions in the solar wind propagate out to the Earth and causing magnetic storms and Space Weather. Finally, as the solar wind continues outwards it pushes back galactic cosmic rays, which are a major hazard to long term travel in space. In this way the rhythmic cycle of solar activity exerts an important control over the Earth’s radiation environment.