Moreover, as Mervyn King, deputy governor of the Bank of England, pointed out at Jackson Hole, there are measurement errors on the other side.

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Ascertaining the binary nature of the system also allowed the astronomers to make their accurate measurement of the bigger black hole's mass.

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When the explorer drills the ice to make a physical measurement of thickness, he will use the hole to lower a 4kg conductivity-temperature device (CTD) into the ocean below.

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The spin measurement, published in Nature, gives precious clues as to how the black hole grew and achieved supermassive status.

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