One petasecond equals 10 to the 15th power seconds. This translates to roughly 31.7 million Earth years. Physicists and geologists use this massive scale to quantify deep time events, such as the half-lives of extremely stable radioactive isotopes or the duration of geological epochs.
Heard on the job
The half-life of iodine-129 is roughly half a petasecond, making it useful for dating early solar system materials.
Insider tip
You will almost never hear this unit spoken aloud outside of theoretical physics seminars or deep-time geology discussions.