Experimenters guide heat around a two-dimensional object
without leaving a trace.
Researchers have devised ways to force light rays to detour
around an object in a way that is reminiscent of the invisibility cloaks of
science fiction. Now a team reporting in Physical Review Letters demonstrates
that they can similarly manipulate the flow of heat on a sheet of metal to hide
a large obstruction in the sheet. Although heat cloaking as such does not have
a clear practical use, the same principles could potentially be used, for
example, to guide the flow of heat or electricity, or the diffusion of
chemicals.