Using a groundbreaking new technique at the National Institute of Standards and Technology (NIST), an international collaboration led by NIST researchers has

The Standard Model describes three fundamental forces in nature: electromagnetic, strong and weak. Each force operates through the action of “carrier particles.” For example, the photon is the force carrier for the electromagnetic force. But the Standard Model has yet to incorporate gravity in its description of nature. Furthermore, some experiments and theories suggest the possible presence of a fifth force.