Where Photons Have Been: Nowhere Without All Components of Their Wavefunctions

A nested interferometer experiment by Danan et al. is discussed and some claims are evaluated concerning the whereabouts of the photon, primarily within the context of time-symmetric interpretations of quantum theory, including the Two-State Vector Formalism (TSVF) and the Transactional Interpretation (TI). It is pointed out that the TSVF account fails to predict the observed data based only on the first-order wavefunction component. It is shown that the Transactional Interpretation readily accounts for all the observed phenomena.