Recent observations of the internal structure of the rare isotope ruthenium-88 shed new light on the internal structure of atomic nuclei, a breakthrough that could also lead to further insights into how some chemical elements in nature and their isotopes are formed. [32] A new technique that allows researchers to cool ions to ultracold temperatures by placing the ions in contact with an ultracold atomic "buffer gas" has been developed by researchers in the Netherlands. [31] Researchers at EPFL have discovered that the viscosity of solutions of electrically charged polymers dissolved in water is influenced by a quantum effect. [30] In terms of physics, the interiors of neutron stars, cold atomic gasses and nuclear systems all have one thing in common: they are gaseous systems made up of highly interactive, superfluid fermions. [29] Engineers at MIT and Penn State University have found that under the right conditions, ordinary clear water droplets on a transparent surface can produce brilliant colors, without the addition of inks or dyes. [28]