# Attosecond

An **attosecond** (**as**) is a very short period of time.^{[1]} It is equal to one quintillionth of a second (or 0.000000000000000001 seconds). It can also be written as **10 ^{−18} seconds**. Because it can be hard to think about how short this period of time is, on this page is a list of descriptions of periods of time longer than 1 attosecond, but shorter than one femtosecond (which is 10

^{−15}seconds). This should help when thinking about periods of time that have different orders of magnitude.

- 1 attosecond: It takes 1 attosecond for light to travel the length of three hydrogen atoms.
- 1 attosecond: It takes 1 attosecond for an atomic nucleus to react when another particle hits it.
- 150 attoseconds: It takes 150 attoseconds for an electron to circle the nucleus of an atom.
- 320 attoseconds: It takes about 300 attoseconds for an electron to jump from one atom to another.

## Related pages

## Notes

- ↑ Website of the BIPM (Bureau International des Poids et Mesures) http://www.bipm.org/en/si/si_brochure/chapter3/prefixes.html Archived 14 October 2011 at WebCite