Black holes may transition into white holes, ejecting matter and even time back into the Universe, according to a new study by physicists from the University of Sheffield and the Universidad Complutense de Madrid. Steffen Gielen & Lucía Menéndez-Pidal study the quantum dynamics of a planar black hole, requiring unitarity in the natural time coordinate conjugate to the cosmological constant of motion appearing in unimodular gravity. Image credit:...
