turpinrt

Okay. Thanks for clarifying.

Thanks for the replies. All of that makes perfect sense. I think my misunderstanding stemmed from an incorrect interpretation of the excerpt I used. I accidentally jumped to the conclusion that "an object" referred to "all objects", or another way I could describe it is I mistook "As long as no external force is acting on an object" as saying "As long as no external force has acted on an object" I was confused because I thought, "if no external force has acted, why and how would the object be moving in a straight line?"

Looking for help to understand some very basic ideas. I'd like to start with this: "In the "flat" space-time of special relativity, where gravity is absent, the laws of mechanics take on an especially simple form: As long as no external force is acting on an object, it will move on a straight line through space-time: at a constant velocity along a straight path." @ http://www.einstein-online.info/spotlights/geometry_force Why? Why will an object move at all if no external force is acting on it? How does this relate to "an object at rest will remain at rest..." If you can point me in the direction of understanding this, thanks in advance.