The Doppler effect (or Doppler shift), named after the Austrian physicist Christian Doppler, who proposed it in 1842 in Prague, is the change in frequency of a wave (or other periodic event) for an observer moving relative to its source. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession.

Plasma is one of the four fundamental states of matter (the others being solid, liquid, and gas). Heating a gas may ionize its molecules or atoms (reducing or increasing the number of electrons in them), thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions.

Balluta Bay is a bay on the northeast coast of Malta within St. Julian's. It is a popular recreation spot used for swimming, diving, and water sports, with a triangular pjazza surrounded by cafes and shaded by Judas trees.

Its skyline is dominated by the neo-gothic Carmelite Parish Church and the stunning art nouveau Balluta Buildings, which are apartment buildings on the eastern shore, as well as a cluster of terraced townhouses in the local variant of Georgian-style architecture. The south shore of Balluta Bay features Le Meridien St. Julian's Hotel, built on the grounds surrounding the 18th century Villa Cassar Torregiani.

The Peace Corps is a volunteer program run by the United States government. The stated mission of the Peace Corps includes three goals: providing technical assistance; helping people outside the United States to understand American culture; and helping Americans to understand the cultures of other countries.

The title Grandmaster is awarded to chess players by the world chess organization FIDE. Apart from World Champion, Grandmaster is the highest title a chess player can attain. Once achieved, the title is held for life.