Mar. 2, 2012 Almost three years ago a team of scientists at the
U.S. Department of Energy's Lawrence Berkeley National
Laboratory (Berkeley Lab) was performing an experiment in which
layers of gold mere nanometers (billionths of a meter) thick
were being heated on a flat silicon surface and then allowed to
cool. They watched in surprise as peculiar features expanded and
changed on the screen of their electron microscope, finally
settling into circles surrounded by irregular blisters. The
circles varied in diameter up to a few millionths of a meter,
and in the center of each was a perfect square. The mysterious
patterns were reminiscent of nothing so much as so‑called
"alien" crop circles. Until recently the cause of these strange
formations remained a mystery. Now theoretical insights have
explained what's happening, and the results have been published
online by Physical Review Letters. Eagerly melting alloys When
two solids are combined in just the right proportions, changes
in chemical bonding may produce a