There's much in mouthful of M&Ms
By The New York Times



In possibly the biggest advance in the science of candy since the discovery that Wint-O-Green Life Savers emit faint blue sparks when chewed, scientists are reporting today that M&Ms pack more tightly in your mouth than gum balls.

Besides being a publicity boost for Mars Inc., which makes M&Ms, the research, whose results appear in the journal Science, could lead to better understanding of glass -- the scientific term for any solid with a random arrangement of atoms or molecules -- and to practical developments, such as stronger ceramics.

"The questions involved here are really quite deep and quite fundamental," said Salvatore Torquato, a professor of chemistry at Princeton University and an author of the Science paper.

The research is a more complicated version of a long-studied problem: how tightly identical spheres can be packed together. Neatly stacked, as in a pyramid of oranges at a grocery store, spheres occupy 74 percent of the available volume. Arranged randomly, however, spheres fill only 64 percent of the space.

In the new research, the scientists considered spheroids: spheres stretched into cigar shapes or squashed into M&M shapes. Stacked neatly, the spheroids still take up 74 percent of the space, just as spheres do. But in random arrangements, computer simulations and experiments with M&Ms showed that spheroids could be packed much more densely than spheres, filling up to 71 percent of the space and not just 64 percent.