The Faster-Than-Light Telegraph That Wasn’t
In 1981 physicist Nick Herbert leveraged strange features of quantum mechanics to design a superluminal communication system. The quest to uncover its subtle flaw led to a profound new understanding of the quantum world.
This discovery became known as the “no-cloning theorem”: a powerful statement about the ultimate foundations of quantum theory. An arbitrary or unknown quantum state cannot be copied without disturbing the original state.