Sound Paths

Sound Paths

. Sound rays are bent inside the Sun, like light within the lens of an eye, and circle the solar interior in spherical shells or resonant cavities. Each shell is bounded at the top by a large density drop near the photosphere and bounded at the bottom by an increase in sound speed with depth that refracts a downward propagating wave back toward the surface. The bottom turning points occur along the dotted circles shown here. How deep a wave penetrates and how far around the Sun it goes before it hits the surface depends on the harmonic degree, l. The white curve is for l = 0, the blue one for l = 2, green for l = 20, yellow for l = 25 and red for l = 75. (Courtesy of Jørgen Christensen-Dalsgaard and Philip H. Scherrer.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University