An Einstein–Rosen bridge is a theoretical solution of general relativity that connects two separate regions of spacetime through a tunnel. It is essentially the original mathematical model of what is now called a wormhole.
Wikipedia: Einstein–Rosen bridgeThe EPR paradox shows that quantum mechanics predicts strong correlations between entangled particles over large distances, suggesting “spooky action at a distance.” Bell’s theorem later showed that no local hidden-variable theory can explain these correlations, and experiments confirmed Bell’s inequalities are violated, supporting quantum mechanics.
Wikipedia: Einstein–Podolsky–Rosen paradoxThe pictures were painted with watercolor and later edited using the open-source software Krita.