Bubbles in micro- or zero- gravity

Bubbles in micro- or zero- gravity show some striking behaviors. Such experiments are often conducted on the International Space Station or parabolic flights.

During April, 2012, Don Pettit, a NASA astronaut, conducted an experiment by injecting bubbles into bubbles on the International Space Station. Without gravity, the rim between bubbles becomes very thick and can also last for a long time. Don Pettit also used laser to reflect different layers of bubbles.

Bubble experiment made by Don Pettit on the International Space Station. From Youtube. Also reported by DailyMail.

The bubbles made by Don Pettit are usually referred as antibubble, which is is a thin film of air surrounding liquid.

A schematic show of antibubble. Source

In 2010, Japanese astronaut Naoko Yamazaki mixed red tropical fruit juice with soap and blew shiny red bubbles. Because of zero-gravity environment, color pigments can spread evenly around a bubble in space. But on the earth, due to the gravity, the bubble will be colorless with the same recipe.

 

Bubble on the earth (left) and on the space (right). Source Also refer to Link.

"Flash&Splash" team, officially affiliated with the Cavitation Research Group at EPFL (École Polytechnique Fédérale de Lausanne, Switzerland),  has conducted a series of experiments of fundamental research on bubbles on the parabolic flights. Water drops with centimetric diameters were produced by the micro-gravity platform (Obreschkow et al., 2008, p.15). An electrode was used to generate cavitation bubbles. The shock wave propagation in this confined water drops was visualized and studied. Bubble collapse under variable gravity was also compared.

Parabolic flights by Airbus A300 zero-g managed by European Space Agency (ESA). From Flash & Splash. Link Also refer to Obreschkow et al. (2008, Fig.1a).

Cavitation bubbles inside water drops in microgravity. Obreschkow et al. (2007). Download link

Cavitation bubbles in variable gravity. From EPFL webiste Link. Also refer to Obreschkow et al. (2011).

Based on the data of bubble sonoluminescence collected on parabolic research aircraft of NASA, Tom Matula (Applied Physical Laboratory, University of Washington, USA) concluded that the sonoluminescence intensity increases in microgravity.

References

Matula, T.J. (2000). Single-bubble sonoluminescence in microgravity, Ultrasonics, Volume 38, Issues 1–8, March 2000, Pages 559–565.

Obreschkow, D. et al. (2011). Universal Scaling Law for Jets of Collapsing Bubbles, PRL 107, 204501 (2011). pdf

Obreschkow, D. et al. (2008). Microgravity experiment: The fate of confined shockwaves, Proceedings o WIMRC cavitation forum 2008, July,7-9, Coventry, UK, pp.15-19.

Obreschkow, D. et al. (2007). Cavitation bubbles inside water drops in microgravity, APS DFD Movie contest.