For the first time, two atomic clocks have developed quantum entanglement.

Atomic clocks have been quantum entangled

by researchers, enabling more precise synchronization. Such entangled clocks could be used to more precisely examine dark matter and gravity.Quantum entanglement, a characteristic that inherently binds them so that changes in one instantly affect the other, has been used to connect two atomic clocks. The link makes it simpler to synchronize the clocks, which might be used to detect gravity and dark matter more precisely.

Atoms are used in atomic clocks, which are controlled with extreme precision by lasers. Each "tick" represents a regular and observable change in the energy of the electrons in an atom. The outcome is...