Alka Seltzer Dropped in Water and Microgravity

An Alka Seltzer (TM) tablet is dropped into water and moments later is dropped in free fall. A free fall like this creates a microgravity environment during the time the experiment is in free fall. This experiment was designed and built by middle school students and was conducted in the 2.2 Second Drop Tower at NASA Glenn Research Center as part of the WING student program. The tablet falls to the bottom of the container due to gravity-driven sedimentation and bubbles are formed as usual when the tablet is dropped into water. The bubbles rise to the water surface due to gravity-driven buoyancy. When the container is dropped in free fall, the effects of gravity (sedimentation and buoyancy in this case) are drastically reduced. While in free fall, the tablet floats upward, bubbles stop their rapid upward motion. Notice that the water surface also becomes curved during free fall due to surface tension and interaction between the water and the container wall. The 2.2 Second Drop Tower is described here: http://facilities.grc.nasa.gov/drop/