Physicists just dropped a bomb. Imaginary numbers? Maybe unnecessary.
Researchers from Heinrich Heine University Düsseldorf and the German Aerospace Center revisited the math underpinning reality. Their findings suggest we don’t actually need complex numbers to describe the quantum world. Just real numbers. Plain old numbers.
Quantum mechanics doesn’t demand the imaginary axis to function.
This goes back to the weird stuff. Atoms and particles do things that defy common sense. They act like waves. They tunnel through barriers. They link up across distances. The founders—Planck, Bohr, Heisenberg, Schrödinger—built a framework to explain it all. And that framework worked. Brilliantly.
But it relied on complex numbers.
Real parts plus imaginary parts. This structure handles amplitude and phase. It calculates how systems evolve. It tells us what we might see in an experiment. For a long time, this math felt indispensable.
Or so we thought.
The Postulate Problem
The debate is old. Are complex numbers fundamental features of nature? Or are they just convenient tools for calculation?
A 2021 study said they were fundamental. Experiments backed them up. Case closed. Or was it?
Dagmar Bruß and Pedro Barrios Hita looked closer. Specifically at the postulates describing combined systems. The old model used a specific postulate about how systems come together. It was restrictive. Too restrictive, they argue.
By swapping that postulate for a more physically motivated one, the whole landscape shifts. They found a class of theories that uses only real numbers. Real numbers alone.
And here is the kicker.
You can’t tell the difference. Experiments would yield the exact same results. The predictions are identical.
Bruß puts it simply: “Within this framework, imaginary numbers are … not fundamentally necessary.”
So why use them? Tradition. Convenience. Habit?
Who knows.
The new paper, published in Physical Review Letters, leaves the door open. Maybe we strip out the imaginary part and keep the physics. Maybe the math just simplifies.
Or maybe it’s all just different hats for the same head. 🎩
The work stands. The reference is solid (Hita, Trushechkin, et al., June 18, 2026).
Whether we switch back to real numbers is a choice now. Not a law of nature.
