0 0.5 1 1.5 2 2.5 3 3.5 a − 3 / 2 (10 3 m − 3 / 2 ) 20 10 9 8 7 6 5 a (mm) 0 10 20 30 40 50 60 70 80 f (Hz) Power (arb. units) 0 0.5 1 1.5 2 2.5 3 3.5 −20 −10 0 10 t (s) E (mV) x10 a = 5.8 mm a = 5.8 mm l =2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 FIG. 2: Bottom: photodiode voltage E measuring the shape oscillations of an a = 5 . 8 mm water droplet. Center: power spectrum of the oscillations of an a = 5 . 8 mm water droplet, as a function of oscillation frequency f = ω/ 2 π . Top: measured frequencies f of the oscillation modes of water droplets with radii between a = 4 . 5 mm and 14 mm, up to l = 16. The broken lines show the Rayleigh frequency spectrum for a water drop, according to Eqn. 1. The measured frequencies (crosses) are slightly higher, by ∼ 1 Hz, due to the effect of the magnetogravitational potential trap. t/τ$_{l}$ ). The power spectrum of these oscillations is shown in Fig. 2, center. Several peaks are evident in this spectrum, corresponding to the l = 2 to 7 Rayleigh modes of the drop. Peak 1 is due to a small oscillation of the droplet’s center of mass of about L$_{0}$ (amplitude ∼ 1 mm). The frequency of this peak is independent of a . The upper panel of Fig. 2 shows the measured peak positions for different drops with radii between a = 4 . 5 mm and 14 mm; the broken lines show the Rayleigh frequency spectrum for a water drop, according to Eqn. 1. Note that the measured frequencies are slightly higher , by ∼ 1 Hz, due to the effect of the magnetogravitational potential trap. We shall calculate this frequency shift in the following 6