What came first: Chicken or Egg. Or Both at the Same Time?

Philosophers of Ancient Greece devised the “Chicken or Egg Paradox” to describe the problem of determining cause-and-effect. No one can conclusively vote for either “chicken” or for “egg” as the cause or effect; chicken comes out of egg and egg comes out of chicken!

A team of physicists from The University of Queensland, Australia and the NÉEL Institute, France has established the weirdness of quantum physics by showing that “both chicken and the egg came first!” They proved that in in quantum physics, cause-and-effect is not always as straightforward as one event causing another, which they call “indefinite causal order”. The results are published in Physical Reviews Letters by the American Physical Society.

They proved their point by referring to the working of photonic quantum switch. It is expected that the transformations on the shape of light depends on polarization. However, the team has shown that: “By measuring the polarization of the photons at the output of the quantum switch, we were able to show the order of transformations on the shape of light was not set."

The researchers anticipate to use this principle, e.g. to make computers more efficient or to improve communication."