At a certain point when increasing the oscillation frequency of a vessel filled with liquid, a heavy rigid ball gets suspended and “freezes” at a distance from the bottom; at a higher frequency, the ball rises to the surface. When the frequency is reduced, the ball continues to float almost until the vibration stand stops completely. The low frequency of oscillations at the end of the experiment is indicated by the transparency of the liquid, free from any air bubbles captured from the surface. Similar effects are observed in wide vessels.

The suspension, rise to the surface, and retention of the body on the surface are associated with certain hydrodynamic and acoustic effects [2–4]. The latter are due to the compressibility of a liquid holding air bubbles and to the paradoxically low speed of sound in such a medium.

The work of many researchers in this area was largely inspired by the classic paper by V. N. Chelomey [1].

References
1. Chelomey V. N. Paradoxes in mechanics caused by vibrations // Reports of the USSR Academy of Sciences. 1983. Vol. 270, No. 1. pp. 62–67.
2. Blekhman I. I., Blekhman L. I., Vaisberg L. A., Vasilkov V. B., Yakimova K. S. “Abnormal” phenomena in liquids under vibration // Reports of the Academy of Sciences. 2008. Vol. 422. No. 4. pp. 470–474.
3. Blekhman L. I. On vibratory buoyancy force and vibratory buoyancy // Obogashchenie Rud (Mineral Processing Journal). 2013. No. 4. pp. 21–29.
4. Blekhman I. I., Vasilkov V. B., Yakimova K. S., Shishkina E. V. Generation of slow fluid flows by a disk vibrating near the wall (on the theory of vibration pumps) // Obogashchenie Rud (Mineral Processing Journal). 2001. No. 1. pp. 36–38.