a Swedish Physicist known for his path breaking work in magnetohydrodynamics and its applications in plasma physics. Most of his work was done at the Swedish Royal Institute of Technology in Stockholm. His most famous achievement is the description of the magnetohydrodynamics (hydromagnetic) wave, commonly called the Alfvén wave. These are disturbances transmitted through plasma in the presence of a magnetic field. Alfvén waves have been observed in the solar wind and magnetic fields surrounding planets. Alfvén also made important simplifications to our understanding of plasmas and demonstrated a way of calculating particle orbits. Hannes Alfvén received the Nobel Prize in Physics in 1970.