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Corbett et al.
Corbett et al. (Google), 2012. The first widely-deployed system to provide externally-consistent (linearizable) transactions across global data centers. The trick: TrueTime, an API that exposes clock uncertainty bounds, backed by GPS and atomic clocks in every data center. Transactions wait out the uncertainty interval before committing, guaranteeing global ordering. Influenced CockroachDB, YugabyteDB, FoundationDB. The paper that proved 'CAP says you can't have C+A under partition' isn't the same as 'C+A is impossible at global scale' — with the right hardware, you can get pretty close.