At the quantum level, determining time becomes the simplest task. Scientists have proposed a new method. The researchers’ experiments on Rydberg atoms have opened up a new way to measure time that does not require a precise starting point. In such atoms, the outer electron is in a highly excited state. As a result, the size of a Rydberg atom can exceed the size of the same atom in the ground state by almost 106 times.

It is irradiated with a laser to change an atom from the ground state to the excited state. In some applications, a second laser can be used to monitor changes in the electron’s position, including time. A wave packet may consist of several Rydberg states. As with real waves, the presence of multiple wave packets oscillating in space creates interference. These unique patterns will reflect the specific time it takes for wave packets to form in line with each other.

In new experiments, physicists have shown that such patterns are persistent and reliable enough to be a kind of quantum timestamp. “The advantage is that you don’t need to initialize the clock – just look at the interference pattern and say, ‘OK, 4 nanoseconds has passed’.”scientists explained.