Units of time used by the Sphere

Standard units:

One standard cycle is the longest unit in use. It is equal to the half-life of hydrogen's smallest radioactive isotope: tritium.

The Sphere uses three other time units, that derive from the standard cycle: the period, the shift and the spin.

The spin is the smallest time unit in use.

Here is the breakdown:

• 250 000 spins = 1 shift
• 4 shifts = 1 period
• 1000 periods = 1 cycle

Non-standard units:

Various non-standard units may be used in several places of the galactic arm. The most common of which is the day. It applies only to ground-living people, and is obviously only relevant to one celestial body at a time. When talking about longer periods of time, even non-travelling persons living on a specific celestial body will tend to revert to standard units and not use their local days and years, as to avoid confusion.

Conversion to human time units

The Sphere's time units can be converted into Earth's units. Here is the breakdown:

• 1 Standard Cycle = 12,32 Earth years
• 1 Period = 4,49 Earth days
• 1 Shift = 1,12 Earth days
• 1 Spin = 0,38 Earth seconds

One may notice the gap between a spin and a Shift, especially when related to Earth's time units. There are no known equivalents of an Earthian minute or hour, for instance. Or at least not in widely used standard units.

Scholars from Earth actually studied this subject after they became aware of the Sphere's existence. Their conclusions state that there had indeed been smaller units used in the past, though none of it was standard, as the Sphere didn't exist at the time. However, with the ascendance of the Haruspii came the rejuvenations, and thus the Sphere. At that point, the ruling classes began to live for so long that small units of time became irrelevant to them. As such, no standard unit below the period was created.

The shift and spin were only added long after, because of their wide usage in naval circles. Both units had been deemed necessary to describe shift management for crewmembers (hence the "shift"), and to transmit travel time and coordinates with sufficient accuracy.