The term wave is often intuitively understood as referring to a transport of spatial disturbances that are generally not accompanied by a motion of the medium occupying this space as a whole. In a wave, the energy of a vibration is moving away from the source in the form of a disturbance within the surrounding medium (Hall 1980, p. 8).
The first soldier to be buried in Arlington was Private William Henry Christman of Pennsylvania on May 13, 1864. There are 396 Medal of Honor recipients buried in Arlington National Cemetery, nine of whom are Canadian.
1 In 1968 Congress made Memorial Day a federal holiday and declared the official date to be the last Monday in May (took effect in 1971).  At Arlington more than 260,000 gravestones and about 7,300 niches are decorated by soldiers. Additionally 13,500 flags are placed at the Soldierâs and Airmenâs Cemetery.