The speed of light was a mystery for millennia, a fugitive constant that escaped measurement and understanding. Now among the ...

Black hole and Big Bang singularities break our best theory of gravity. A trilogy of theorems hints that physicists must go ...

The National Institute of Standards and Technology (NIST) has dramatically enhanced the precision of time measurement with ...

Abstract: We summarize the development of microfabricated atomic frequency references at NIST. The physics packages of these devices have volumes near 10 mm/sup 3/ and power dissipation below 150 mW, ...