Fracturing across the multi-scales of diverse materials.

Everyone has to deal with fracturing of materials at one level or another, beginning from normal household chores and extending to the largest scale of observations reported for catastrophic events occurring on a geological level or even expanded to events in outer space. Such wide perspective is introduced in the current introduction of this theme issue. The follow-on organization of technical articles provides a flavour of the range in size scales at which fracturing occurs in a wide diversity of materials-from 'fracking' oil extraction and earth moving to laboratory testing of rock material and extending to the cracking of tooth enamel. Of important scientific interest are observations made and analysed at the smallest dimensions corresponding to the mechanisms by which fracture is either enhanced or hindered by permanent deformation or other processes. Such events are irrevocably linked to the atomic structure in all engineering materials, a sampling of which is presented, including results for crystalline and amorphous materials. Hooray for the broad subject description that is hoped to be appealing to the interested reader.