
/// Electrons moving at relativistic speeds have a mass that is greater than their rest mass.
// fn moving_electron_mass(velocity) -> f64 {
//     static LIGHTSPEED_2: f64 = powf(super::constants::LIGHTSPEED, 2.0);
    
//     let c: &f64 = &super::constants::LIGHTSPEED;
//     // gamma = 1 / sqrt(1 - v^2/c^2)
//     // let gamma = powf(1.0 - powf(velocity, 2.0)/LIGHTSPEED_2, -0.5);
//     // nicer for the compiler to do:
//     //  c / sqrt((c+v)(c-v))
//     gamma = c / powf((c + velocity) * (c - velocity), 0.5);
    
//     super::constants::ELECTRON_MASS * gamma
// }
