Add a Media Piece
default edit
Back to the Gallery

This medium is available via another website:

Click here to view it.

Title: Waves in a large free sphere of water and an effervescent antacid tablet on the Internation Space Station

Description: Part 1: Waves in a Large Free Sphere of Water
A 13 centimeter diameter free sphere of water was held stationary in front of a video camera by a wire loop. A 10 cubic centimeter pulse of air was radially imparted against the surface from about 2 centimeters distance within about 100 milliseconds. The resulting disturbance formed a series of surface waves and spherical body waves that created a number of delightful interactions. The surface waves behaved like water ripples confined to a "spherical pond" and converged on the antipodal point 180 degrees from the initial impulse. The surface waves dampened leaving longer-lived spherical body oscillations.

Part 2: Water Droplets in a Bubble in a Sphere
A 75 millimeter diameter water sphere was held stationary in front of a video camera by a wire loop and a 35 millimeter diameter air bubble was injected into the center of the water sphere. Water droplets, 1 to 8 millimeters in diameter were then injected into the air bubble. This "symphony of spheres" provided an amazing display of droplet interactions seemingly in a game of three dimensional billiards. There were many near-elastic collisions between droplet-droplet and between droplet-inner bubble wall. About once every 6 to 8 collisions, a mass exchange would take place from the droplet through the inner bubble wall. This mass exchange resulted in momentum transfer thus changing the droplet trajectory. Droplets were made to move in circular motion around the inner bubble surface, held against the wall from radial acceleration forces. It is speculated that the droplets slide on this interface like a hockey puck on ice.

Part 3: An Effervescent Antacid Tablet in a Water Sphere
An effervescent antacid tablet was placed into contact with the free surface of a 50 millimeter diameter water sphere held stationary in front of a video camera by a wire loop. Contact wetting forces drew the tablet within the volume of the sphere. Heterogeneous bubble nucleation resulted from the chemical reaction of the tablet with the water that liberated carbon dioxide. The bubbles were ejected from the tablet surface with a small outward directed velocity where they would quickly coalesce into larger bubbles. Large bubbles coalesce with smaller ones at a faster rate than smaller bubbles coalesce, thus larger bubbles would feed from the smaller ones and grow even larger. The resulting dynamics would leave two large bubbles vying for the remaining smaller ones that were wedged into the interstitial volume between the larger bubbles. Eventually, only one large bubble would remain with the smaller ones confined to a thin spherical shell.

Credits: Donald R. Pettit


Web Page:

Contributed By: Tausif Billah

The eFluids editor for videos is G. M. "Bud" Homsy (
and for images is Jean Hertzberg (
Please contact them if you have any problems, questions, or concerns related to the galley or videos and images.
© Copyright on the videos is held by the contributors.
Apart from Fair Use, permission must be sought for any other purpose.