Quantum entanglement is a strange and fascinating phenomenon in quantum physics where two or more particles become so deeply linked that the state of one particle instantly affects the state of the other—no matter how far apart they are. This connection persists even across vast distances, such as kilometers on Earth or even between planets in space.

When particles become entangled, their properties (like spin, polarization, or momentum) are correlated in a precise way. For example, if two entangled particles are created with opposite spins, measuring the spin of one particle will immediately determine the spin of the other, even if it’s light-years away.

This appears to defy classical ideas of space, time, and information transfer, which led Einstein to famously call it “spooky action at a distance.” However, quantum entanglement does not allow faster-than-light communication, because the outcome of each measurement is still random—only the correlation is predictable.

Entanglement is not just a theoretical curiosity; it’s essential in emerging technologies such as:

• Quantum computing: for performing complex calculations using entangled quantum bits (qubits),
• Quantum cryptography: for ultra-secure communication using entangled photon pairs,
• Quantum teleportation: for transferring quantum states over distance.