"If you're using a stopwatch, you first need to define a starting point," explains physicist Marta Berholts. However, scientists in Sweden have discovered a groundbreaking method to measure time without needing a "starting point." This innovative approach, developed at Uppsala University in 2022, delves into the realm of quantum physics, utilizing "Rydberg" atoms.
Rydberg atoms, energized by lasers, become enormous, with electrons behaving in unpredictable ways. By analyzing the wave-like structures formed by these electrons, physicists can obtain "fingerprints" that trace time. The "pump-probe" technique involves exciting an atom with one laser pulse and then monitoring its changes over time with a second pulse.
The resulting wave patterns offer fixed references for measuring time, allowing scientists to determine the passage of time simply by observing the wave pattern. "In this technique, you can just look at the wave pattern and say, 'okay, 4 nanoseconds have passed,'" Berholts clarifies. Researchers plan to refine this method further by experimenting with different atoms and laser pulses beyond helium.