Earphone definition, a sound receiver that fits in or over the ear, as of a radio or telephone. See more.
Answer Wiki. If a rocket went straight up, it would either continue in that direction and leave Earth, or it would fall back down, depending on its velocity. Most rockets intend to enter orbit, which is an elliptical trajectory, and it's much more efficient to arc into this trajectory than to go straight up and then accelerate laterally.
1 Objects can appear to move in the sky either because they are actually moving, or because they reflect our motion through space.  For stars, almost all apparent motion comes from reflex motion, because they are so far away that their intrinsic motion appears very small.