what is an attosecond
An attosecond is an incredibly tiny unit of time equal to one quintillionth of a second, written as 10−1810^{-18}10−18 seconds.
What Is an Attosecond? (Quick Scoop)
Ultra‑tiny slice of time
- Definition: An attosecond (symbol as) is 0.0000000000000000010.0000000000000000010.000000000000000001 seconds, i.e., 10−1810^{-18}10−18 seconds.
- That’s one quintillionth of a second.
- There are about as many attoseconds in one second as there are seconds in the age of the universe.
Think of it this way:
An attosecond is to one second what one second is to roughly 31–32 billion years.
So if a single second were “stretched” to the age of the universe, an attosecond would be like a single second inside that cosmic span.
Why scientists care about attoseconds
Attoseconds show up in ultrafast physics and chemistry , where everything happens absurdly quickly.
- Electrons in atoms and molecules move and rearrange on attosecond timescales.
- To “see” this motion, researchers use attosecond light pulses – incredibly short flashes of light.
- This has given rise to attosecond spectroscopy , where scientists track how electrons move during processes like chemical reactions and charge transport in materials.
Previously, femtosecond (10−1510^{-15}10−15 s) pulses were fast enough to study slower atomic nuclei, but not fast enough to resolve electron motion; attosecond pulses finally match the speed of electrons.
How small is it compared to other time units?
Here’s a quick feel for where an attosecond sits among common “tiny time” units:
| Unit | Seconds | Relation to attosecond |
|---|---|---|
| Nanosecond | $$10^{-9}$$ | 1 nanosecond = 1,000,000,000 attoseconds |
| Femtosecond | $$10^{-15}$$ | 1 femtosecond = 1,000 attoseconds |
| Attosecond | $$10^{-18}$$ | Base unit here |
| Zeptosecond | $$10^{-21}$$ | 1 attosecond = 1,000 zeptoseconds |
Attoseconds in recent news and prizes
Attoseconds have been in the spotlight because generating and measuring attosecond pulses led to major breakthroughs:
- Researchers developed techniques to create attosecond light flashes and use them to study electron dynamics.
- This attosecond science underpinned the 2023 Nobel Prize in Physics , awarded for experiments that use attosecond pulses to probe electrons inside atoms and molecules.
- Articles and explainers from late 2023 highlight how a “billion billion” attoseconds pass in the short time you read a sentence, yet those intervals are exactly what matter at the quantum scale.
So when you see discussions, forum threads, or news headlines asking “what is an attosecond?” today, they’re usually talking about this new ability to take ultrafast snapshots of electrons – like going from a blurry long‑exposure photo to a crisp high‑speed camera.
TL;DR
- An attosecond = 10−1810^{-18}10−18 seconds, one quintillionth of a second.
- It’s so short that one second contains about as many attoseconds as the universe’s age contains seconds.
- Attosecond pulses of light let scientists watch electrons move, enabling new physics and chemistry experiments and helping inspire a recent Nobel Prize in Physics.
Information gathered from public forums or data available on the internet and portrayed here.
