The (Im)possibility of Detecting a Fifth Dimension

We show that it is impossible to rule out the existence of a fifth dimension using the classical tests of relativity in the solar system. A similar impasse occurs in certain cosmologies. However, it might be possible to detect a fifth dimension indirectly, via its effects on vacuum energy, thermodynamics or spin.

A THEORY OF SPACE, TIME AND MATTER

We unify the gravitational field with its source by considering a new type of 5D manifold in which space and time are augmented by an extra dimension which induces 4D matter. The classical tests of relativity are satisfied, and for solitons we obtain new effects which can be tested astrophysically. The canonical cosmological models are in agreement with observations, and we gain new insight into the nature of the big bang. Our inference is that the world may be pure geometry in 5D.