Cady Coleman and Ron Garan measure the orbiting radius of a water droplet as it circles a piece of statically charged rubber tubing on the International Space Station. (NASA)
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An example of water 'bending' towards a static charge created by a balloon.
(Image credit: ©Faith Fashion & Photos LLC)
View large image Even simple scientific experiments can yield amazing results and add to the collective knowledge of the research community. Take the winning proposal for the most recent round of the Kids in Micro-g competition, for example, which was designed by two 5th grade girls from Chabad Hebrew Academy in San Diego. Conducted in April 2011 on the International Space Station, this study, called "Attracting Water Drops," looked at static attraction in microgravity to reveal an exciting new understanding of physics in space.
Kids in Micro-g was a hands-on design challenge and part of NASA's Teaching from Space education program. Six finalists were selected in the 2011 Kids in Micro-g competition, earning the chance to have their proposed studies performed on the space station. The Attracting Water Drops experiment involved rubbing a piece of rubber tubing with a pair of nylon shorts to create a static charge. Then astronauts released a droplet of water close by and watched to see what happened.
Marilyn Sniffen, advanced placement science coordinator with Chabad Hebrew Academy, found out about the Kids in Micro-g competition while researching new challenges for her students online. Having previously participated with her classes in other NASA education challenges, she was aware of NASA as a resource to help foster a love of science in students. "I asked my current students if they would like to participate," said Sniffen. "There was no hesitation, as they immediately wanted to check out the list of supplies available for the physics tests that could be done aboard the space station."
Students did their own companion study in the classroom to gain results for the investigation under the force of gravity here on Earth. They observed that a piece of charged rubber tubing held near a stream of running water caused the flow of water to bend toward the tubing. Students learned that the action of rubbing the tubing with nylon transferred negatively charged electrons to the tubing, creating a negative static charge. Since opposite charges attract to each other, and water molecules have a polarity with a positive end, the negatively charged tubing held near the water caused the positive end of the water to draw towards the tubing.
Astronauts Cady Coleman and Ron Garan performed the Attracting Water Droplets experiment aboard the station on April 23, 2011. You can view a video of the investigation being performed here . Their objective was to study the electrostatic interaction of the charged rubber tubing and water drops in microgravity. Students anticipated a greater attraction of the water droplet to the electrostatic charge than found on Earth. "Their hypothesis was that the results in space would be dramatically different than on Earth," commented Sniffen. "This is because the force of gravity on the water was greater than the force attraction to the static charge on the tube."
In addition to successfully proving the hypothesis, however, students and crew members were astonished to see the water droplet actually orbit the charged piece of tubing. "Look at that!" exclaimed Cady Coleman during the experiment on the space station. "It is going around our tubing. You would think it would keep sailing; in microgravity it would keep sailing, but it is coming back to our tubing and around."
Sniffen echoed Coleman's surprise, as she detailed the student's expectations for the water droplets in space. "The students predicted that in micro-g, the drop would be free floating and that it could be 'pulled' around by the charged rubber tube without it falling to the ground. The actual experiment on the station showed they were able to pull the drop around in the air, but it also revealed a surprise we didn't predict. The droplet of water actually orbited the tube at about 6 cm! So our hypothesis was supported, but we learned something entirely new in the process. The kids were amazed, as were we!" said Sniffen.
The school plans to repeat the Earth-bound portion of the experiment while showing the video of the study done on the space station to allow more students to share in the science next school year. "This kind of collaboration is really important for our students as they so often feel that what they are learning in school has no real connection to everyday life," comments Sniffen. "This program has allowed our students to make connections with real science and scientists, real discovery, and other students. It has inspired analytical thinking, creativity and communication for all our students."