Any matter dissolved (or otherwise suspended) in the superfluid will tend to aggregate together in clumps, encapsulated by a 'quantum solvation shell '. Due to the totally frictionless nature of the superfluid medium, the entire object then proceeds to act very much like a nanoscopic ball bearing, allowing effectively complete rotational freedom of the solvated chemical species. A quantum solvation shell consists of a region of non-superfluid helium-4 atoms that surround the molecule(s) and exhibit adiabatic following around the centre of gravity of the solute. As such, the kinetics of an effectively gaseous molecule can be studied without the need to use an actual gas (which can be impractical or impossible). It is necessary to make a small alteration to the rotational constant of the chemical species being examined, in order to compensate for the higher mass entailed by the quantum solvation shell.