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.

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 Republican Party, also commonly called the GOP (for "Grand Old Party"), is one of the two major contemporary political parties in the United States, the other being the Democratic Party. Founded by anti-slavery activists in 1854, it dominated politics nationally for most of the period from 1860 to 1932. There have been 18 Republican presidents, the first being Abraham Lincoln, serving from 1861 to 1865, and the most recent being Donald Trump who began serving in 2017.

The Mayan languages form a language family spoken in Mesoamerica and northern Central America. Mayan languages are spoken by at least 6 million indigenous Maya, primarily in Guatemala, Mexico, Belize and Honduras. In 1996, Guatemala formally recognized 21 Mayan languages by name, and Mexico recognizes eight more. The Mayan language family is one of the best documented and most studied in the Americas. Modern Mayan languages descend from Proto-Mayan, a language thought to have been spoken at least 5,000 years ago.

Deadweight tonnage is a measure of how much weight a ship is carrying or can safely carry. It is the sum of the weights of cargo, fuel, fresh water, ballast water, provisions, passengers, and crew.