The primary responsibilities of human resources are: 1  C - Compensation. 2  H - Human resource development. 3  E - Employee and labor relations. 4  S - Safety and health. 5  S - Staff.
A new technique uses sound waves to levitate objects and move them in mid-air. Credit: Dimos Poulikakos View full size image. View full size image. Hold on to your wand, Harry Potter: Science has outdone even your best Leviosa! levitation spell.
In fact, sound moves faster through water than it does through air. But whether in air or in water, sound moves much more slowly than light does. While light travels at 186,000 miles per second, sound only goes 0.2 miles per second (343 meters per second, or about 770 miles per hour).