Sure, I understand that...... 
Sure, I understand that......
You understand addition.
Exponential sums are like addition that is performed faster and faster. It’s an accelerating addition.
Simple example with arithmetic:
It takes say 1 sec to add X + X
It takes half the time to add another X.
So now we have that it takes 1.5 sec to add (X + X) + X.
Each time we add an X to the total, it takes only half the time as before.
The result is exponential, an addition process that is increasing at an increasing rate, i.e. acceleration.
If the NASA boys and girls can get a miniscule amount of thrust from an EM Drive and they keep adding small amounts at an increasing rate, they are going to get a huge amount of thrust via an exponential process.
The point was to counter the misunderstanding that a miniscule amount of thrust was not worth the effort.
In nuclear physics, it’s similar. We split one atom and we get a barely noticeable release of energy. If we split a quadrillion atoms, the energy is enormous.
In the context of this EM Drive, an amount of thrust causes movement. Adding more thrust causes faster movement. Adding more and more thrust causes acceleration. There would seem to be no end to it except that in frictionless space, the speed attained in limited by the speed of light.