What is Quantum Entanglement?

Quantum Entanglement. What is it? In quantum physics, entangled particles remain connected so that actions performed on one affect the other, even when separated by large distances. Entanglement occurs when a pair of particles, like photons, interact physically. What causes it? Quantum entanglement occurs when two particles become linked and whatever happens to one immediately happens to the other, regardless of how far apart they are. How are entangled photons created?. A laser beam fired through a certain type of crystal can cause individual photons to be split into pairs of entangled photons. 

The photons can be separated by a large distance, hundreds of miles, or even more. When observed, Photon A takes on an up-spin state. Entangled Photon B, though now far away, takes up a state relative to that of Photon A (in this case, a down-spin state). The transfer of state between Photon A and Photon B takes place at a speed of at least 10,000 times the speed of light, possibly even instantaneously, regardless of distance. A proposed experiment would send one photon of the entangled pair to the orbiting International Space Station, a distance of around 310 miles. This would be the largest distance that has been experimentally tested.

Many people believe that quantum entanglement could be used to communicate faster than the speed of light, but it's not possible yet. Scientists are making new discoveries every day and soon we will be able to fully understand and utilize Quantum Entanglement.