FOR THE discerning timekeeper, solely an atomic clock will do. Whereas the perfect quartz timepieces will lose a millisecond each six weeks, an atomic clock may not lose a thousandth of 1 in a decade. Such units underpin every part from GPS and the internet to stock-market trading. That will appear ok for many. However in a paper lately printed in Nature, researchers report being able to construct its successor: the nuclear clock. Ekkehard Peik, one of many discipline’s pioneers, says such a clock may very well be an element of 1,000 occasions higher than at present’s customary atomic clocks.