Sometimes the simplest of things becomes extremely complex when you look closely. For example, how many times have you turned a sheet of paper into a near perfect sphere before throwing it in the trash ? Have you ever wondered what mechanism we use to transform a simple sheet of paper into that very resistant "ball"? Two physicists from the University of Massachusetts, Narayan Menon and Anne Dominique Cambou, have asked themselves this question. And they have gotten some interesting answers by studying the structure in 3 dimensions using an X-ray microtomography machine.
Among the conclusions, the researchers highlight that a piece of paper compressed manually to become a sphere contains 90% air . Furthermore, they have observed that the outer areas are always denser than the inner ones. On the other hand, taking into account that it is a structure created at random, the only pattern they have found is that the flat areas tend to fold and rest on other flat areas, forming parallel sheets, a phenomenon that seems to contain the key to the paper ball resistance, the authors suggest in the journal Proceedings of the National Academy of Sciences ( PNAS ).
