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.
They move across the sky because the earth is rotating and that â¦ makes it look like the stars are moving. Just like the sun does not move across the sky, the earth rotates and the sun appears to move, the same is with the stars.