Without getting into a mathematical explanation, can anyone who reads this posting explain to me how there can be a "tractive" force in our world. For example, a vessel that is evacuated with atmospheric pressure on the outside is said to have been "sucked in" (a tractive cousin) while in reality the vessel collapsed due to the external forces (pressure) on the outside (a pushing force). When you bring a strong magnet into proximity of a steel ball bearing, the ball bearing at some point will begin to move toward the magnet- someone might say that the ball bearing was being drawn-attracted-pulled toward the magnet ! I don't buy it!! I have a theory, but I want to hear from an educated person what their spin is on this example. Please answer!! This seeming mystery/enigma between "pushing" and "pulling" forces has been bothering me for so long that I can't stand it anymore. I need help!!