Speed of Light Slowed to a Standstill from 1.08 billion km/h in Landmark Experiment

Using lasers and glass fibers, researchers managed to stop the speed of light in an experiment that could have profound effects on making quantum communications an everyday reality.

Scientists at the Vienna University of Technology (TU Wien / Vienna Center for Quantum Science and Technology) first slowed the speed of light to 180 km/h then managed to bring the light to a complete stop and to “restart” it again later.

This achievement is an important prerequisite for future glass fiber-based quantum internet in which quantum information will be teleported over great distances. Quantum communications will also make eavesdropping impossible.

The TU Wien scientists slowed down the speed of light from its typical speed in a vacuum of 1.08 billion km/h (300 million meters per second) to 180 km/h using fiber optics, which is the system currently used around the world for telecommunications. This made their results even more useful in the real world.