Bubble (physics)
A bubble is a globule of a gas substance in a liquid. In the opposite case, a globule of a liquid in a gas, is called a drop.[1] Due to the Marangoni effect, bubbles may remain intact when they reach the surface of the immersive substance.
Common examples
Bubbles are seen in many places in everyday life, for example:
- As spontaneous nucleation of supersaturated carbon dioxide in soft drinks
- As vapor in boiling water
- As airmixed 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
- As the indicator in a spirit level
Physics and chemistry
Bubbles form and coalesce into globular shapes because those shapes are at a lower energy state. For the physics and chemistry behind it, see nucleation.
Appearance
Bubbles are visible because they have a different
The above explanation only holds for bubbles of one medium submerged in another medium (e.g. bubbles of gas in a soft drink); the volume of a
Applications
Nucleation can be intentionally induced, for example, to create a bubblegram in a solid.
In medical ultrasound imaging, small encapsulated bubbles called contrast agent are used to enhance the contrast.
In thermal
The violent collapse of bubbles (
Bubbles are used by chemical and metallurgic engineer in processes 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.[3]
The star-nosed mole and the American water shrew can smell underwater by rapidly breathing through their nostrils and creating a bubble.[4]
Research on
Bubble lasers use bubbles as the optical resonator. They can be used as highly sensitive pressure sensors.[6]
Pulsation
When bubbles are disturbed (for example when a gas bubble is injected underwater), the wall oscillates. Although it is often visually masked by much larger deformations in shape, a component of the oscillation changes the bubble volume (i.e. it is pulsation) which, in the absence of an externally-imposed sound field, occurs at the bubble's
where:
- is the specific heat ratio of the gas
- is the steady state radius
- is the steady state pressure
- is the mass density of the surrounding liquid
For air bubbles in water, smaller bubbles undergo
Excited bubbles trapped underwater are the major source of liquid
Physiology and medicine
Injury by bubble formation and growth in body tissues is the mechanism of decompression sickness, which occurs when supersaturated dissolved inert gases leave the solution as bubbles during decompression. The damage can be due to mechanical deformation of tissues due to bubble growth in situ, or by blocking blood vessels where the bubble has lodged.
See also
- Antibubble
- Bubble fusion
- Bubble sensor
- Foam
- Minnaert resonance
- Nanobubble
- Sonoluminescence
- Underwater acoustics
References
- ISBN 9780521496056.
- ^ R. J. Dijkink, J. P. van der Dennen, C. D. Ohl, A. Prosperetti, The ‘acoustic scallop’: a bubble-powered actuator, J. Micromech. Microeng. 16 1653 (2006)
- ISBN 978-0-486-44580-9.
- ^ Roxanne Khamsi. "Star-nosed mole can sniff underwater, videos reveal".
- ^ Whitcomb, Isobel (August 6, 2019). "The Key to Life's Emergence? Bubbles, New Study Argues". LiveScience. Retrieved January 8, 2022.
- ^ Miller, Johanna. "Bubble lasers can be sturdy and sensitive". Physics Today. American Institute of Physics. Retrieved 2 April 2024.
- ^ Minnaert, Marcel, On musical air-bubbles and the sounds of running water, Phil. Mag. 16, 235-248 (1933).
- ^ a b Leighton, Timothy G., The Acoustic Bubble (Academic, London, 1994).
- PMID 29599511.
- .
- ^ Rankin, Ryan C. (June 2005). "Bubble Resonance". The Physics of Bubbles, Antibubbles, and all That. Retrieved 2006-12-09.