The article doesn't go far enough in showing the genius of the SI system (known as metric system most of the time). The conversion factor between mechanical va

The article doesn't go far enough in showing the genius of the SI system (known as metric system most of the time). The conversion factor between mechanical values in the SI system is 1. Example: E = F * delta_x = m_1 * a * delta_x = 0.5 * m_2 * v^2 Energy = 1 J = 1 kg * m^2/s^2 = 1 N * 1 m // Force: 1 Newton applied for 1 meter distance = 1 kg * 1 m/s^2 * 1 m // Acceleration: 1 kg accelerated at 1 m/s for a distance of 1 m = 0.5 * 2 kg * (1 m/s)^2 // Velocity: 2 kg accelerated from stand still to 1 m/s velocity So you can see that no magic factors popped up at any point. This is because the SI system describes the real world very well: for example mass and force are rigorously defined units and can not be used interchangeably.