Take a paper clip, and pull one of the ends sideways. If you pull gently and release, it will elastically rebound to its original shape like a spring. If you pull harder, it deforms permanently into a new shape, a process called yielding. On page 251 of this issue, Csikor et al. (1) provide convincing theoretical evidence that, rather than a smooth process, yielding is like a phase transition that consists of a series of small avalanches. These avalanches not only provide the microscopic underpinnings we need to build theories of how ordinary-sized objects bend, but Csikor et al. further argue that the avalanches become crucial problems for controlling bending on micrometer and nanometer scales (see the figure).
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