Seven Truths That Can't Coexist in the Quantum World ✎ express
We are used to thinking that events have causes, objects exist independently, and signals cannot outpace the speed of light. Quantum mechanics, which describes the Standard Model of particles, challenges all these assumptions at once — as if a recipe couldn't use all seven ingredients.
Scientists have named this impossibility a heptalemma (a seven-sided dilemma). Any six statements coexist with quantum experiments, but the seventh is always superfluous. Rejecting a specific thesis determines which picture of the quantum world we adopt.
The heptalemma becomes a culinary test: if a physical system obeys all seven conditions, it is classical, akin to spacetime curvature in Einstein's theory. Violating any point transports us to the quantum kitchen. Six ingredients are enough to bake all of classical physics — from falling apples to the motion of galaxies.
Six of the seven statements fully describe all of classical physics — from the falling apple to the rotation of galaxies. The seventh ingredient always turns out to be redundant.
A universe where all seven theses held would be classical and empty — without stars, atoms, or life.