Main Page | See live article | Alphabetical index Main Page | See live article | Alphabetical index Yoctosecond A yoctosecond is one septillionth (10^-24) of a second. The word yoctosecond is formed by the prefix yocto and the unit second. It is abbreviated as ys. For a list of times on the order of 1-10 yoctoseconds, compare 1 E-24 s. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.