For the Team Third assignment, our team chose to capture the “dancing” of a liquid inside a singing bowl.

A Singing bowl, also known as a standing bell, is an artifact that is played to generate a sound that is considered by many as soothing or relaxing, and is commonly used to invoke meditation. These are made with brass and other alloys, and are most commonly hand-made, making each of them unique. The singing bowl creates sound when a stick, called a striker or a mallet, is moved across its edge while adding a little pressure on the edge. These are sometimes played after adding water halfway in the bowl. The sound is created because of the bowl resonating due to the movement of the striker on its edge. The bowl can have a single or multiple resonant frequencies and harmonics. This particular bowl had resonance at 310Hz and 818Hz. As these bowls are handmade, each of them would have a different resonant frequency.

As the bowl starts resonating, waves start forming in the liquid which could be described as Faraday waves. As the amplitude increases, the wall of the bowl starts oscillating enough to launch small droplets of the liquid that come in contact with the wall. These droplets are launched inwards and bounce on the surface waves of the liquid and eventually coalesce with the liquid. Surface tension plays a big role here, as having a lower surface tension leads to droplets easily breaking off at the walls. Due to this, isopropyl alcohol (rubbing alcohol) was utilized for this experiment instead of distilled water, as isopropyl alcohol has a surface tension of around 22dyn/cm as opposed to around 72dyne/cm of distilled water. It was interesting to observe the droplets of liquid bouncing for quite a long time on the agitated surface of the liquid, and immediately coalescing once the singing bowl stopped playing.

Multiple diffused white light sources were utilized to illuminate the bowl and its liquid. The camera utilized was a Pixel 6 primary camera as my Canon EOS 1500d DSLR could not record 4k and at a higher fps. Recording at higher fps was needed for slow-motion playback. The camera settings are as follows:

• Camera – Pixel 6 primary camera
• Aperture – f/1.85 fixed
• Sensor – 50MP 1/1.31″
• Focal length – 24mm equivalent
• Recorded in 4k (3840p x 2160p) at 60fps
• Slow-motion video playback at 2.5x (40% playback speed) resulting in 24fps

The report can be accessed here: