Addiction: Central nervous system (CNS) stimulants are addictive, even if they are not abused. Many factors, including the patient's personal history, the type of stimulant that is being taken, the dose of the drug, and duration of use, influence how likely an individual is to become addicted.
The source of all waves - mechanical or electromagnetic - is something that is vibrating. Matthew Donovan.
1 Waves in the ocean are mostly generated by the wind moving across the ocean surface. 2  The medium is the substance or material that carries a mechanical wave.  One of the most important things to remember about waves is that they transport energy, not matter. This makes them different from other phenomenon in physics.