The world has powerful computers almost everywhere around us thanks to a technology called semiconductor lithography.
Semiconductor lithography is the science of printing intricate circuits with extreme precision.
The smallest feature size that can be moulded on the silicon wafer is governed by a physics principle called the Rayleigh scattering criterion.
According to this criterion, the size of the feature to be projected on the wafer is proportional to the wavelength of light used and inversely proportional to the aperture of the lens that collects light before projecting it onto the wafer.