Computer simulation showing oscillations on the surface of the Sun. The Sun's surface is known to oscillate up and down like the surface of a wobbling jelly. The effect is due to the presence of sound waves of different frequencies, bouncing back & forth within the Sun. This simulation shows a combination of only 100 modes of oscillation; ten million different modes are known to exist. The height of the oscillations has been exaggerated by a factor of 1000 in this image. Each of these bumps moves up and down once every 5 minutes or so; the exact period of oscillation of each mode carries information on the structure & dynamics of the interior of the Sun.