What is the furthest distance particles can interact and still become entangled?

[DWRLRX]

I was wondering, what is the farthest two particles can interact and still become entangled, and what form of interaction would this require, gravitation? Also, would this be assumed the same in regards for the entanglement of macroscopic objects?

 

[humanino]

There is no such distance, entanglement remains at arbitrary distances until "measurement" occurs. No interaction occurs between the two entangled particles, rather the two entangled particles do not exist as separate entities before "measurement".

For macroscopic objects, "measurement" occurs in the form of decoherence exponentially fast with the size of the objects.