Any motion which repeats itself at regular intervals of time is known as periodic motion. If a body moves back and forth repeatedly about its mean position then it is said to be in oscillatory motion.

Researchers successfully observed petahertz (PHz: 1015 of a hertz) electron oscillation. The periodic electron oscillations of 667-383 attoseconds (as: 10-18 of a second) is the fastest that has ever ...

One fundamental problem of quantum electrodynamics is the fate of the superheavy atomic nucleus, which is proposed to collapse when the atomic number exceeds certain value. However, this intriguing ...