In 1935, physicist Erwin Schrödinger sought to draw an analogy to quantum superposition by positing what became known as Schrödinger’s cat: A cat in a box, he argued, could, by the interpretation of fellow scientists Niels Bohr and Werner Heisenberg, be both alive and dead until an observer confirmed its state.

He found the idea problematic, but Schrödinger’s cat nevertheless became foundational to quantum mechanics.

In the opening salvo of the Israel and U.S. attack on Iran, Supreme Leader Ali Khamenei perished.