Useful Measurements

A question came up on the boards recently about units of measurement in the Antarean universe. Many are already established across the supplements, so we thought it might be a good idea to pull them together into one place.

Distance – yan and petayan

The yan is the normal distance of measurement for height and length (approximately five metres or one rod), then there is kiloyan, milliyan, etc. If you need to, directionality has to be something that, in 3D space, uses relative declination. For ease of _our_ understanding it might be a good idea to keep to degrees as every world is likely to have a different measurement and the IMTel would translate it’s own, internal system to whoever was listening!

In-system measurements use the Standard Astronomical Unit (SAU), based on an ancient standard that approximates to 30 million kiloyan. This probably came from Old Earth – wherever it is, now.

Light years are rarely needed as almost everything goes through the Antarean Gate and the destination may not be in the departure system’s time period, anyway. Indeed, it is possible that it isn’t even in our universe (Antares rulebook, p.212)! The time taken to another system is normally far more important as it involves travel through the gates, from/to the gates and across the Antarean surface.

If distance to a nearby star is needed, and as parsecs are somewhat relative to the system on which they’re based, anyway (and the IMTel would consider it strange to switch from yan to ly to parsec!), it might be an idea to use petayan where 2 petayan approximates to a light year. So, for us, a parsec (3.26 light years) is a little over 6 petayan.


The trouble is that every planet has a slightly different day and year, so local years are far more important for crop cycles (and perhaps for celebrations) than the Antarean year. Months are fairly meaningless and may vary from system to system based on the year, if months or weeks are used at all.

However, absolute time for humans is measured in our standard seconds, and an abstract day and year based on an arbitrary estimate of that from Old Earth. Stating the current date varies but for system- or planet- independent peoples is from the start of the current ‘Age’, e.g. 7A.1322 (we’re just over 1300 years into the Seventh Age (Antares rulebook, p.207).

In contrast, it is likely the IMTel bases it’s time measurement on the number of decay periods of an elementary particle from the establishment of the IMTel before the Seventh Age. this gives a rather large number, so it has to translate for mere biologicals.  The core notation is likely to be days in year, such as 1322.191, but we have to stress that every planet will have its own for local use.

A SOL is the standard for sub-light speed, in a similar way that ‘quantum’ is used to express probability by the IMTel. 100 SOL = 100% of the speed of light, and 1 SOL = 1/100 the speed of light. Max in-system velocity is around 10 SOL for safety reasons (Ghar are somewhat slower; good warships manage up to 15 SOL) purely because of the need to deflect the detritus around stars away from the starships.

Spaceship acceleration

Normally, it is acceleration that is important. However, the nature of interstellar and in-system detritus is such to affect the real-space deflectors integrated into the advanced races gravitic drives.Here, again, the IMTel (probably frustrated by now!) has had to translate into human terms, choosing as standard the most comfortable and healthiest human gravity (G) of around 2 yan/s².

The best Isorian military scout starships can accelerate at well over 200G, whilst the clunky Ghar drives can barely manage 50G. In both cases gravitic compensation makes things comfortable for those onboard (for Ghar, erratically so).

However fantastic such accelerations, they are limited in use because of the material deflection mentioned above. Even out the plane of the ecliptic, the shell of material around a star limits maximum velocity and it is only is ‘true’ interstellar space that higher velocities are possible.

However, even then, there is no guarantee of an unobstructed vector so, if they are attempting such a strange journey, those starships are still limited in maximum velocity. So why not use Antares instead and save the years muccking about in real space? Sure, the Isorians tried it – but look what happened to them!