A website documenting concrete ships from World War I and World War II, including ice cream barges and Mulberry Harbour components. The site uses cookies for traffic analysis and user experience optimization.
The returning soldier effect is a demographic phenomenon where male births increase relative to female births following periods of war, first identified in 1883 by Carl Düsing. Multiple theories explain the effect, including soldier health differences, genetic factors related to height, hormonal changes in women, and increased coital rates, though modern prenatal sex determination and sex-selective abortion have obscured the original pattern in recent decades.
Hyperbolic navigation is a radio-based system that determines location by measuring timing differences of signals from synchronized beacon transmitters, producing hyperbolic curves that intersect to pinpoint position. First used for acoustic artillery detection in World War I, hyperbolic radio systems like Gee, Decca, and LORAN were widely deployed in the mid-20th century until GPS and satellite navigation replaced them in the 1990s.