What:

"As an analogy, imagine you are paving a highway that runs in two directions. You have machines that will pave the highway, but can only run in the direction of normal traffic flow. The two machines have to stay near each other. By running one constantly and having the other pave in the opposite direction, then moving the machine farther back and going until it meets the part it just paved, you get the same effect."

Writer:

LCC:

Where:

Date: Apr 2 2016 3:30 PM