Langley's Ark - Don't touch the firebombs

The Laws of 'mancy
'mancy is the act of taking raw personal power, focusing it through a component, and sending it out in physical or semi-physical manifestations. In short - magic. However, it has developed into a science of its own and now, any scientist worth mentioning has at least a touch of 'mancer in him.
There is a special set of natural laws regarding 'mancy. Just like Newton's apple, 'mancy has rules of physics it must follow. While these are different from the normal ones, they still share some similarities. For instance, if velocity is measured by starting velocity plus acceleration times time, adding a 'mancer would change the formula. Using a chronomancer slowing down time as an example, we'd have: v = v(0) + a*(tc) with c being the amount of personal 'mancer energy expended multiplied by individual talent and quality of component being used as the focus. So instead of an anvil falling at massive amounts of speed, it would fall much slower as the time directly around it would be reduced, thus reducing the velocity. Of course, any expenditure by the 'mancer takes personal energy and so 'mancers can find themselves growing exhausted by excessive use of 'mancy. There are of course consequences to this, and are too varied to explain in any detail. Suffice to say that it's bad.
There are many kinds of 'mancy. Some schools are generalized - like the elemental schools - and others are more specialized. Many schools overlap in areas or work in conjunction with another. Most 'mancers know a bit of all the major schools and specialize in one or two that catch their interest.
In society, 'mancers play the roles of just about everything. They are found in positions of power as government officials, or as scientists and teachers, down to a technician working in a factory that builds skimmers. Practically any endeavor will seek to obtain the service as a 'mancer. Since roughly 40% of the population has some sort of 'mancy talent this usually isn't too difficult. However, only about 20% of the population has significant talent. Furthermore, 'mancy is a 'use it or lose it' ability. If a weak 'mancer fails to receive any sort of training in their childhood years, the chances of them actually retaining it to adulthood are very low. Like muscle, it atrophies, and regaining it is a very difficult process and often not worth the effort for the majority of the populace. So, there remains just enough 'mancers to supply the demand reasonably, but few enough to make them a valuable commodity.
Schools of 'mancy (and common components used as focuses)*

Aermancy - air element (feather, dandelion fluff, aquamarine)
Pyromancy - fire element (twisted rope, fire, ruby)
Technomany - technology (screwdriver, shaped piece of metal, hematite)
Chronomancy - time (pocket watch, sand, fossil)
Bestiamancy - animals or other non-humans (wolf fang, tuft of fur, carved ivory)
Voidmancy - void, mass, matter (prism, warped mirror, piece of string)
Literamancy - written or spoken word (page from a book, ink, stone with 'mancer's name engraved on it)
Gravimancy - gravity (magnet, moonstone, feather)
Necromancy - death and some elements of the human body (bone, skin, blood)

*some components are more effective than others. The included lists are just a sampling and are no measure or accuracy or effectiveness and serve only as examples. However, it should be noted that any component that qualifies as a precious metal or precious gem should be taken with a grain of salt as those are regarded as generic materials that have extremely loose association with a particular school. They are rarely used for serious 'mancy and are regarded as emergency components only by many 'mancers.