Franz Emil Melde (March 11, 1832, in Großenlüder near Fulda – March 17, 1901, in Marburg) was a German physicist and professor. A graduate of the University of Marburg under Christian Ludwig Gerling, he later taught there, focusing primarily on acoustics, also making contributions to fields including fluid mechanics and meteorology. He began in 1860 as Gerling's assistant at the University's Mathematical and Physical Institute, succeeding him in 1864.
Standing waves were first discovered by Melde, who coined the term "standing wave" (stehende Welle) around 1860. What is known as "Melde's experiment", "a lecture-room standby", demonstrates standing waves and their patterns on a string, is used to measure the speed of transverse wave, and to determine the effect of tension, length, and mass on the transverse waves of a string. In 1859 Melde generated parametric oscillations in a string by employing a tuning fork to periodically vary the tension at twice the resonance frequency of the monochord string.
