In a rebroadcast from March 7, 2010, Keith talks with Phillip Wannamaker of the Energy & Geoscience Institute of the University of Utah. He talks about using electromagnetic waves to image the interior of the earth. Wannamaker also talks about how lighting and sunspot activity is used in his research. http://egi.utah.edu/about/staff/phil-wannamaker.php. Aired Sept. 1, 2013.