They have not propelled any mass at the speed of light squared.
Nor at the speed of sound squared, or at the speed of a turtle squared, or that of continental drift squared. Speed (well, velocity) is in units of distance/time, as in meters/sec or furlongs/fortnight. Only those units. Not (meters)
2/(second)
2, like c
2 is in.
You simply have a misconception, Henrik, of what algebra is all about.
Edited by Coragyps, : fix tags?