The current received wisdom is that quantum theory is correct but incomplete. However an examination of the history of the development of quantum theory shows that it is based on an unproven assumption. That assumption, that angular momentum is quantized, leads to the absurdity of the quantum leap and so cannot be valid. All subsequent theories which rely on this assumption must therefore be called into question.If the quantum leap is to be regarded as an absurdity then it follows that the orbital radius of the electron in the hydrogen atom must remain the same for all energy levels. The conditions necessary to bring this about are identified and a model developed for the hydrogen atom. Such a model is only possible if it is assumed that certain velocity terms are affected by relativity. This idea is combined with a second postulate concerning the nature of gravitational mass and is then used to develop a second model, this time for the photon as a compound particle comprising an electron and a positron locked in mutual orbit. This too relies on relativity affecting orbital velocity.Special relativity is unique among physical phenomena in that for objects traveling at significant speeds there are two versions of every measurement. In other words relativity is possessed of a natural duality. There are two ways to measure distance, two ways to measure time and two ways to measure mass depending on who is making the measurement; the stationary observer or the moving observer. This idea can be extended to cover frequency, wavelength. However the relationship between the wave characteristics of a particle and its particle characteristics is the same within each of the two domains and is consistent with classical mechanics. This leads to the idea of a wave/wave duality and a particle/particle duality rather than the current wave/particle duality and effectively unifies the quantum and classical worlds. This duality is shown to pervade many aspects of physics and in so doing provide explanations for phenomena that are otherwise unexplained.