From MSNBC:
Until now, scientists could not explain why ice cubes in your drink melt. They’ve known the basics, but the details remained elusive. A breakthrough new study, announced today, supports a leading theory that melting starts when the fundamental structure of matter begins to crack.
The problem is that the earliest phase of melting has never been seen. Scientists can’t see the atoms involved because they are so small and because they are hidden in the structure of solid material. So the team made some big atoms. Specifically, they made see-through crystals that are like small beads and are visible in an optical microscope.
“The spheres swell or collapse significantly with small changes in temperature, and they exhibit other useful properties that allow them to behave like enormous versions of atoms for the purpose of our experiment,” said Ahmed Alsayed, a University of Pennsylvania doctoral student and lead author of a paper on the results in the July 1 issue of the journal Science.
More here.