Quantum clock: rotating atomic spins have been used to measure the time it takes for quantum tunnelling to occur. (Courtesy: iStock/agsandrew) The time it takes for an atom to quantum-mechanically ...

The photoelectric effect, first explained in 1905, transformed our understanding of how light interacts with matter. When high-energy light hits atoms, it knocks electrons loose. This process powers ...

The weak gravitational pull on a particle just half the mass of a grain of sand has been measured for the first time. This most precise measurement of its kind is a breakthrough towards the quantum ...

Before we can learn how to harness the potential power of atoms, we need to truly understand how they work. Now, we’re one step closer, as physicists have successfully recorded an internal atomic ...

In 1797, English scientist Henry Cavendish measured the strength of gravity with a contraption made of lead spheres, wooden rods and wire. In the 21st century, scientists are doing something very ...

Scientists have measured the shortest unit of time ever: the time it takes a light particle to cross a hydrogen molecule. That time, for the record, is 247 zeptoseconds. A zeptosecond is a trillionth ...

Today’s state-of-the-art optical clocks offer accuracy to 18 decimal places, which is roughly equivalent to measuring the ...

Accurate measurement of time is one of the glories of physics, and one of the most exciting frontiers of current research. For most of history, people measured time using the sun and moon. Earth’s ...

A millimeter might not seem like much. But even a distance that small can alter the flow of time. “This is fantastic,” says theoretical physicist Marianna Safronova of the University of Delaware in ...