The idea of being able to become invisible, especially by simply
covering up a person or an object with a special cloak, has a
perennial appeal in science-fiction and fantasy literature. In
recent years, researchers have found ways to make very exotic
“metamaterials” that can perform a very crude version of this
trick, keeping an object from being detected by a certain
specific frequency of radiation, such as microwaves, and only
working at microscopic scales. But a system that works in
ordinary visible light and for objects big enough to be seen
with the naked eye has remained elusive. This image shows a
calcite crystal laid upon a paper, causing all the letters to
show double refraction. Now, a team of researchers in the
Singapore-MIT Alliance for Research and Technology (SMART)
Centre has found a relatively simple, inexpensive system that
can hide an object as big as a peppercorn from view in ordinary
visible light. The team’s discovery has been published online in
Physical Review Letters and will appear s