This bronze sculpture capturing little Gabriela’s attempts to blow bubbles sits atop a rock near the south end of Shelter Island. Named “Bubble Bath,” the child-size sculpture keeps an attentive eye on the frolicking kids at the Shoreline Park West playground.
Art: BUBBLE BATH
Location: 32°42’39.2″N 117°13’46.5″W
Artist: Dan Hill – http://www.danhillsculpture.com
Learn: A bubble is a globule of one substance in another, usually gas in a liquid. Bubbles form, and coalesce, into globular shapes, because those shapes are at a lower energy state. Due to the Marangoni effect – mass transfer along an interface between two fluids due to surface tension gradient – bubbles may remain intact when they reach the surface of the immersive substance.
Bubbles are seen in many places in everyday life, for example:
- As spontaneous nucleation of supersaturated carbon dioxide in soft drinks.
- As water vapor in boiling water.
- As air mixed into agitated water, such as below a waterfall.
- As sea foam.
- As a soap bubble.
- As given off in chemical reactions, e.g., baking soda + vinegar.
- As a gas trapped in glass during its manufacture.
- An air bubble in a solution of fluorescein and water (or alcohol) is the essential part of a spirit level.
The Physics of Blowing Bubbles
Blowing soap bubbles may be child’s play, but physicists only recently developed a complete theory for the process of soap bubble formation. It was a long and complicated study, which involved building a bubble-blowing apparatus. Scholars developed a model that calculated the effects of several factors, such as the breath velocity, on the process of blowing a bubble.
The research team used their bubble-blowing apparatus to aim a jet of gas at a soap film and learned that bubbles appear only above a threshold gas speed. Like, if you blow a soap bubble too slowly, it pops. By measuring this threshold under varying conditions, the team showed that bubbles result from a competition between the pressure of the gas jet and the surface tension of the soap film.
Understanding the physics of bubbles is important for a variety of industrial processes and scientific fields, from cosmology to foam science, and future applications.
The violent collapse of bubbles (cavitation) near solid surfaces and the resulting impinging jet constitute the mechanism used in ultrasonic cleaning. The same effect, but on a larger scale, is used in focused energy weapons such as the bazooka and the torpedo. Pistol shrimp also use a collapsing cavitation bubble as a weapon. The same effect is used to treat kidney stones in a lithotripter. Marine mammals such as dolphins and whales use bubbles for entertainment or as hunting tools. Aerators cause dissolution of gas in the liquid by injecting bubbles.
Chemical and metallurgic engineers rely on bubbles for operations such as distillation, absorption, flotation and spray drying. The complex processes involved often require consideration for mass and heat transfer, and are modeled using fluid dynamics.
10 Ways to Enjoy:
- Blow bubbles.
- Appreciate the joy of the children on the playground.
- Act like a child.
- Sit on a bench and take in the view.
- Walk along the footpath.
- Enjoy a cold drink.
- See if you can hold your breath for a minute.
- Share a childhood memory.
- Play pattycake.
Share your fun: #SanDiBAT
More: Humans can see bubbles because they have a different refractive index (IR) than the surrounding substance.
While it has been known since 1884 that a spherical soap bubble is the least-area way of enclosing a given volume of air (a theorem of H. A. Schwarz), it was not until 2000 that it was proven that two merged soap bubbles provide the optimum way of enclosing two given volumes of air of different size with the least surface area. This has been dubbed the double bubble conjecture.
The star-nosed mole and the American water shrew can smell underwater by rapidly breathing through their nostrils and creating a bubble.