![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
spallation
May. 19th, 2011 07:14 amspallation (spaw-LAY-shun) - n., the process whereby pieces are ejected from a body due to an impact; esp., the ejection of numerous smaller particles from a nucleus that has been hit by a high-energy particle.
The chips and fragments that come off something you hit are spalls, as are the ejecta from a meteorite impact. The verb form is, of course, to spall, and there is such a thing as a spalling hammer. Spallation was coined in the 1940s (possibly in a nuclear physic context?), but to spall is much older: at least the 15th century, in the sense of a chip, of uncertain origin but possibly germanic root (Old High German had a cognate verb spaltan, to split).
---L.
The chips and fragments that come off something you hit are spalls, as are the ejecta from a meteorite impact. The verb form is, of course, to spall, and there is such a thing as a spalling hammer. Spallation was coined in the 1940s (possibly in a nuclear physic context?), but to spall is much older: at least the 15th century, in the sense of a chip, of uncertain origin but possibly germanic root (Old High German had a cognate verb spaltan, to split).
---L.
