> I'm biased because I'm in the industry, but nothing has cropped up that I've seen that requires a miracle. Scaling is itself the open question. Gravitational

> I'm biased because I'm in the industry, but nothing has cropped up that I've seen that requires a miracle. Scaling is itself the open question. Gravitational effects start creeping in when you scale up sensitive entangled systems and we don't have a good understanding of how gravity interacts with entanglement. Entangled systems above a certain size may just be impossible.