Sometimes we have a desire to retrieve an object that is floating away in a lake or the ocean, and then we will know how frustrating it can be trying to draw that object towards us. But researchers at the Australian National University in Canberra have recently demonstrated the ability of simple wave generators to control things adrift in the water, and even more them against the direction of the waves.
The research was led by Horst Punzmann and Michael Shafts of Australian National University (ANU) and the paper has been published in Nature Physics. They conducted an experiment with ping-pong ball floating in a wave tank. By precisely manipulating the size and frequency of three dimensional waves created by a wave generator, they were able to keep the ball in place, move it away from the generator, or even towards it. Thus they control the movement of the ball using the waves they were generated.
Actually the presence of water current that causes the movement of the ball. Usually waves are produced in water, but the wave is actually just energy. It passes through the water causing the molecules to rise and fall, but they have no movement in any other direction, especially with weaker waves. But the researchers at the Australian National University produce additional current on the surface of the water by changing the size and frequency of the waves which they produced. Some of these currents push the ball along, and other draw it closer.
Although the scientists did establish that the waves generate flow patterns along the surface layer of the water, the actual mathematics behind this phenomenon are still not understood. The project leader of this research Dr. Horst Punzmann said that “It’s one of the great unresolved problems; yet anyone in the bathtub can reproduce it, we were very surprised no one had described it before.”
This research technology can be used to contain oil spills, which would expedite cleanup and could minimize environmental impacts. This will also be useful for better understanding of dangerous rip tides that drag swimmers in to the water even when the waves are heading towards the shore.
If we add this discovery in the syllabus of secondary students, this will create more interest and curiosity among science. Also this will help to make a scientific temper or an investigating mentality among students.