A collaboration between researchers in the US and Germany has made a major breakthrough in optical nuclear clocks, achieving laser-based excitation of Thoria-229 in a non-transparent host material.

For nearly 50 years, physicists have dreamed of the secrets they could unlock by raising the energy state of an atom's nucleus using a laser. The achievement would allow today's atomic clocks to be ...

Scientific clockmakers have crafted a prototype of a nuclear clock, hinting at future possibilities for using atomic nuclei to perform precise measurements of time and make new tests of fundamental ...

An international research team has taken a decisive step toward a new generation of atomic clocks. The researchers have created a much more precise pulse generator based on the element scandium, which ...

To measure time, you need a constant rhythm. For eons, the regular movements of the sun and moon have set the pace for all of life on Earth. But over millennia, humans have sought and found more ...

The famed Michelson-Morley experiment of 1887, in which perpendicular beams of light were raced against each other, seemed to show that a light-carrying ether pervading all space did not exist.