One of the things I love about Mistborn is the magic feels grounded in physics. Steelpushing and ironpulling affect metal in a straight line between you and the object, and the object that moves, and how fast, depends on the relative mass of the two objects. I wanted the magic system in Lightning Born and Silent Scars to have a similar feel, so when they throw electricity around, it behaves like lightning.
It is a plot point in Silent Scars that the magic users have their power diminish. In doing so, I wanted to have real numbers that mean something. So, first I had to decide which variable I wanted my main character to measure. I jumped to a physics website, and started going through the possibilities.
Resistance (Ohms) : Measures how easy it is for electricity to move through material. Important to keep in mind for when the mages are using their magic, but it wouldn’t measure what I’m trying to convey.
Power (Watts) : The amount of energy in a current. This sounds like what I want, but the number really depends on two other variables, potential and current.
Potential (Volts) : The work required to move a charge from point to point. This definitely plays a role in the magic system. I have my mages create something called “potential points” which is how they direct where their electricity is going. It seems to me that it would be hard to directly measure the strength of these potential points. So that leaves me with…
Current (Amps) : The amount of electricity flowing. This is a perfect description for what is happening in the plot, because there is less power to go around. A mage can easily send his/her current through an ammeter to measure it. Awesome.
So now I know what I’m measuring, but what would be a good number? Since my mages can shoot electricity through the air like lightning, I figured that for now, I would base my number on the low range of lightning strikes.
So, according to Professor Google, the average lightning strike is 30,000 amps with typical ranges between 5,000 and 50,000 amps. I chose the base number for my story to be 9,200, since 9.2 is a number I had pulled out of the air earlier as a stand in. If you are an engineer/scholar/whatever, and have a compelling reason why this number should be different, I would be happy to know it!