Scientists think that a chameleon-like field, which shifts its nature based on its environment, could explain dark energy. But a new experiment casts doubt on such theories.
This force would result from a chameleon field — an addition to the known fields in physics, such as electric, magnetic and gravitational fields. A chameleon field with these morphing properties could drive theBut it’s a challenge to suss out such a changeling force. On Earth, says astrophysicist Jianhua He of Nanjing University in China, “it’s very, very tiny. That’s the most difficult part.”
So He and colleagues designed a detector to search for a subtle fifth force. A wheel with plastic films attached spins past another film sitting on a magnetically levitated piece of graphite. If a chameleon force really exists, the films spinning by would cause a periodic force on the levitating plastic, pulling it up and down.
The team was able to rule out a category of chameleon theories. In the future, the researchers hope to improve their results by chilling their device to allow for more sensitive measurements.