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.
Rockets can get you going much faster. The first spacecraft to make the run was the Soviet Luna 1 probe. It completed a flyby in 1959. Luna 1 wasn't trying to get into orbit. It was there to whiz past the Moon and take a few pictures as it went. It completed the journey in only 36 hours, traveling at a speed of 10,500 kilometers per hour.