Shear Alfvén Wave (IMAGE) American Physical Society Caption This is a representation of the three-dimensional magnetic field (due to four currents threading the center of each helix) of a shear Alfvén wave. It was acquired at an instant of time throughout the volume of a large (60 cm diameter ,18m long) plasma in the LAPD device at UCLA. The currents and the field topology change in fractions of a millionth of a second. The sparkles are proportional to the electric field in the plasma induced by the wave. Credit Walter Gekelman, UCLA Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.