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Clock comparison using black holes

Observing accreting black holes in the early Universe allows precise comparison of clocks over intercontinental distances on Earth. This is achieved with a novel observation strategy using the next generation of very long baseline interferometry systems.

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Fig. 1: Schematic outline of future intercontinental clock comparisons.


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Correspondence to Rüdiger Haas.

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Haas, R. Clock comparison using black holes. Nat. Phys. 17, 164–165 (2021).

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