In a remarkable leap for physics, researchers have successfully measured the shortest span of time ever recorded—just 0.000 000 000 000 000 000 247 seconds, or about 247 zeptoseconds (10⁻²¹ seconds). This ultra-brief moment marks the time it takes a photon to traverse a hydrogen molecule, allowing scientists to observe subatomic events with precision previously thought impossible.
Measuring the Tiny:
The experiment, conducted by a team at Goethe University Frankfurt in collaboration with the DESY accelerator facility and Fritz‑Haber‑Institute in Germany, used beams of high-energy X-rays to hit hydrogen molecules (H₂). One photon was tuned to eject both electrons from the molecule, creating electron-wave patterns that the team then detected using a device called a COLTRIMS reaction microscope.
By observing how the electron waves interfered—a bit like ripples in a pond—they deduced how much time passed between the photon reaching the first hydrogen atom and then the second. That tiny delay turned out to be roughly 247 zeptoseconds for the average bond length of the molecule.
Why It Matters:
Until now, time-scales such as femtoseconds (10⁻¹⁵ seconds) and attoseconds (10⁻¹⁸ seconds) were used to explore ultrafast phenomena like chemical bonding and electron motion. But measuring in the zeptosecond range brings a new frontier.
Observing events at the zeptosecond scale means scientists can now watch how electrons and photons behave inside molecules in real time—that is, almost literally at the speed of light. As one of the researchers put it: the electron shell in a molecule does not respond everywhere at once; the information spreads at the speed of light within the molecule.
Potential Applications:
This is not just a showy record: studying such fleeting moments opens doors in several fields:
Quantum physics: Understanding how electrons, photons and atomic nuclei interact at ultra-short times could refine our models of matter and energy.
Material science & nanotechnology: On these time-scales, the fundamental interactions that determine how materials behave can be studied directly, potentially enabling the design of materials with tailored atomic-scale dynamics.
Electronics & photonics: As devices shrink and operate faster, knowing exactly how electrons move and respond could lead to breakthroughs in ultrafast switches, quantum devices or even new computing paradigms.
Chemical reactions: If we can monitor how bonds form, break or shift on the zeptosecond time-scale, it may become possible to steer reactions, influence outcomes, or create new reaction pathways.
How It Worked – In Simple Terms:
1. A hydrogen molecule (two hydrogen atoms bonded) is targeted by an X-ray photon.
2. That photon has enough energy to kick out both electrons.
3. The first electron is freed, then, slightly later, the second one is freed (due to the distance between the atoms and the finite speed of light).
4. Each freed electron forms a wave. These two waves overlap and interfere. The interference pattern shifts depending on the timing difference.
5. By measuring that shift and knowing the geometry, the scientists calculate the time delay: ~247 zeptoseconds.
6. Thus they indirectly measure the time it took for the photon‐electron interaction sequence in the molecular scale.
Why the Term “Zeptosecond”?
A zeptosecond is 10⁻²¹ seconds—that’s one trillionth of a billionth of a second. For perspective: there are as many zeptoseconds in one second as there are seconds in roughly 2,500 times the age of the universe.
What the Future Holds:
With this achievement, the door opens to more refined measurement of ultrafast processes and perhaps eventually reaching even shorter time-scales. Technological advances in ultrafast lasers, detectors and measurement techniques will push these boundaries further. Some theoretical work already outlines methods for pushing into the “zepto‐exawatt” regime or compressing free electrons into zeptosecond pulses.
To sum up: measuring 247 zeptoseconds is not just about breaking records—it’s about giving humanity a new kind of “clock” for the quantum world. One that ticks at the speed of light inside molecules.
Source:
Scientists have measured the shortest unit of time ever: the time it takes a light particle to cross a hydrogen molecule. Live Science (October 2020)
“Zeptoseconds: New world record in short time measurement.” Goethe University Frankfurt (October 2020)