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Laser technique measures distances with nanometre precision
A new technique involving lasers can measure long distances more precisely than ever, which could be useful for space telescopes
A new way to gauge distance using lasers can measure lengths of more than 100 kilometres to within a thousandth of the width of a human hair, and could be used to make better space telescopes. In lab-settings, scientists can use lasers to measure distances with extreme precision, to within a few nanometres. But for longer distances of a kilometre or more, the precision of these techniques tends to be much lower, to within around a millimetre.
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