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.
The Sun is the source of energy for most of life on Earth. It derives its energy mainly from nuclear fusion in its core and releases it into space mainly in the form of radiant (light) energy.