Imagine 100 cars painted gold, all at point A...

Imagine 100 cars painted aluminum, all at point B.

At the signal (start), the gold cars start driving towards B. At the same time, the aluminum colored cars start driving towards A. However, the aluminum cars run much faster than the gold colored cars... you will reach a point where all the aluminum cars have reached point A, but no gold colored cars have reached point B...

That situation creates a void.... Kirkendall voiding



Mark Goodson