A twist in the universe’s first light could hint that scientists need to rethink physics. 

A pair of Japanese scientists looked at the polarization or orientation of light from the cosmic microwave background radiation, some of the earliest light emitted after the universe’s birth. They found the polarization of photons, or light particles, might be slightly rotated from their original orientation when the light was first produced. And dark energy or dark matter may have been responsible for that rotation. (Dark energy is a hypothetical force that is flinging the universe apart, while proposed dark matter is a substance that exerts gravitational pull yet does not interact with light.)