High school science teaches us that light can act either as a particle or a wave. So, theoretically, light should not be able to squeeze through a hole whose width is smaller than the wavelength of the light. Experiments performed in 1988 have shown that light does get through certain patterns of such tiny holes. Now new experiments show that less light flows through the holes etched on a thin film of gold (so thin that it was already translucent to light). In fact, more light flowed through the gold than through the holes etched in the gold film itself.
[ To learn why, read the full article at: Science ]