2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/135486The undoing of quantum measurements is discussed in the broader context of irreversibility in physics. We give explicit examples of how a wavefunction can be uncollapsed in two solid-state experimental set-ups. Wavefunction uncollapse shows the quantum observer paradox in a new and significantly clearer way.8 pages, 4 figures, proceedings paper for Coherence and Quantum Optics 9Quantum PhysicsMesoscale and Nanoscale Physicstext