Stuck in the dirt

日期:2019-03-07 05:07:01 作者:长孙午瞅 阅读:

TO GET something moving across a surface, you have to give it an initial shove. But scientists have never understood why. Now Martin Muser of the University of Mainz and his colleagues have shown that dirt is to blame. In Physical Review Letters (vol 86, p 1295) they suggest that particles of dirt and grime catch in the gaps between the two jagged surfaces,