Crumpling a piece of paper and making it into a "paper ball" is so ordinary an act that we do it all the time and few will think the paper ball is worthy of investigation. Mr. Y. C. Lin, however, certainly did not think so. In his senior year, Y. C. Lin crumpled a lot of paper and made paper balls not out of frustration but as subjects for his research into "physics of crumpling." Supervised by Professor Hong Tzay-Ming, Mr. Lin submitted his research findings in a paper entitled "Three Dimensional Experiment on Crumples" to Physical Review Letter, the most authoritative journal in the U.S.. His paper was accepted and published on September 19, 2008.

Although "physics of crumpling" is a relatively new subject, it is a phenomenon that occurs in many situations, including plate movement that forms mountains, car accidents on freeways and, of course, even when you rumple a sheet of paper at your desk. Imagine yourself holding a piece of paper in your hand. With all your might you rumple it but only to find that the ball shows a high level of resistance and, in the end you have no choice but to stop! At the same time, you probably did not realize that the ball still contains over 70% air. It remains to be a mystery as to why a crumpled sheet can have resistance at that level, though scientists believe it has to do with the complicated distribution of pointy structures and creases. Lin designed an instrument that can rumple a sheet into a ball by air compression. He first crumples the sample by hand and wraps it with ceram-wrap. Then he inserts an air duct that extends outwardly in order to inject high pressure gas into the instrument. Since the sample is separated from the gas by the ceram-wrap, it is subjected to the pressure difference and an enormous amount of ambient pressure. This is the simple design with which Lin and his team systematically studied the physics of crumpling.

Professor G. Gompper of the German IFF-Institute reported in Nature in 2006 that power law exists between the size of crumpled sheet and external force. Power law can be observed in many situations, such as Newton's law of gravitation, Coulomb's static force and even the currently much discussed long tail theory that commonly exists in economic systems. Gompper's report especially pointed out that power law of crumpled sheet is a common phenomenon. This means that the same relationship can be found in any type of sheet, regardless of size, thickness or toughness. Lin's experiment proves that the theory is partly right and in need of modification. In samples of the same material, the same correlation is found between the size of compressed ball and external force, but samples of different material show different power.