UK researchers have demonstrated the highest-resolution optical microscope ever - aided by tiny glass beads. The microscope imaged objects down to just 50 billionths of a metre to yield a never-before-seen, direct glimpse into the "nanoscopic" world.
The team says the method could even be used to view individual viruses. Their technique, reported in Nature Communications, makes use of "evanescent waves", emitted very near an object and usually lost altogether.
Instead, the beads gather the light and re-focus it, channeling it into a standard microscope, allowing researchers to see with their own eyes a level of detail that is normally restricted to indirect methods such as atomic force microscopy or scanning electron microscopy.
Using visible light - the kind that we can see - to look at objects of this size is, in a sense, breaking light's rules. Normally, the smallest object that can be seen is set by a physical property known as the diffraction limit.
Light waves naturally and inevitably "spread out" in such a way as to limit the degree to which they can be focused - or, equivalently, the size of the object that can be imaged.
At the surfaces of objects, these evanescent waves are also produced.