The paper is about entanglement, which is not "a single particle that exists in two places at the same time." By definition quantum entanglement "occurs when p

The paper is about entanglement, which is not "a single particle that exists in two places at the same time." By definition quantum entanglement "occurs when pairs or groups of particles are generated or interact." [Quantum entanglement](http://en.wikipedia.org/wiki/Quantum_entanglement http://en.wikipedia.org/wiki/Quantum_entanglement) > To summarize, we have shown that entanglement can affect the gravitational field. This suggests that entanglement “has a weight”. The perturbations in the gravitational field depend on the amount of entanglement and vanish for vanishing quantum correlations. The effects studied in this work decay with a time scale proportional to the characteristic “size” of the particle. Furthermore, the contributions to the metric are relevant only if particle positions are not extremely larger than this characteristic size. A prospective theory of quantum gravity must be able to account for this phenomenon and explain its origin. [On the weight of entanglement](http://arxiv.org/pdf/1412.4007v1.pdf http://arxiv.org/pdf/1412.4007v1.pdf)