CELL theories of liquid helium have been proposed by several investigators1. They distinguish successfully between the statistics of helium-3 and helium-4 but are unable to reconcile the measured energy gap with the distance of the observed nearest neighbour. Co-operative motion of the cells accounts without difficulty for the phonon spectrum, but the assumption of weak coupling between the diatomic rotors and the acoustical vibrations is inadequate. The analysis recorded here is a new attack on the nature of the excitations which account for the normal component.
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