|
|
|
|
|
|
Symbol | Definition |
---|---|
≡ | exactly equal |
≈ | approximately equal to |
= | equal to |
digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |
Petasecond is equal to 1 000 000 000 000 000 second (unit of time), comes from a combination of the metric prefix peta (P) with the second (s). Plural name is petaconds with symbol is Ps.
A moment (momentum) was a medieval unit of time. The movement of a shadow on a sundial covered 40 moments in a solar hour.