Ricegrain-sized atomic clock
The US National Institute of Standards and Technology has come up with an atomic clock the guts of which measure 1.5 x 4 mm, which they claim is 100X smaller than any rival. Unfortunately it would end up measuring a slightly less impressive 1 cubic centimetre once an oscillator and control circuits are attached, but it looks like a big use for this might be in military location devices where space is not at such a premium. Benefits down at the user end should include better accuracy for GPS receivers.
