New quantum technology, and the measurement and definition of time

Einstein's relativity, optical atomic clocks, and November's Perimeter Institute public lecture from David Wineland. With some added geek nostalgia

A while ago the Independent asked me, and others, to share some science books that have excited us. My choice was "Science and the Universe" from the Mitchell-Beazley Joy of Knowledge library. In a pre-wikipedia (and for me pre-O level) age, this book opened up a whole landscape of amazing ideas - ideas backed by facts.

The page I remember best is the one on the "Idea of Relativity"^1, which amongst other things shows cosmic muons lasting longer than usual because of the time-dilation effects of their high speeds. I think that must have been the first time I came across muons, or cosmic rays. But the illustration that stuck in my mind most strongly was that of a light clock, in which a ray of light is reflected between two mirrors.