Prior to the development of radar in the late 1930s, Great Britain relied on a network of concrete acoustic mirrors built along its southern and eastern coasts to detect incoming enemy aircraft. Designed by acoustic pioneer William Sansome Tucker, these curved structures functioned by reflecting and focusing sound waves onto a central point, where a listener equipped with stethoscopes could hear the engine noise of distant planes. While the mirrors could detect aircraft up to twenty-five miles away, their efficacy was highly contingent on ambient meteorological conditions; high winds or coastal surf could easily drown out the focused sound waves. Furthermore, the rapid increase in aircraft speeds during the 1930s rendered the detection window provided by the mirrors too narrow for effective defense mobilization, leading to the system's retirement in favor of radio-based detection.
Based on the text, which statement is true about the acoustic mirrors?
- AThey utilized radio waves to alert listeners equipped with stethoscopes to the presence of enemy planes.
- Their operational success was dependent on the state of the weather and noise from the shoreline.Cevap
- CThey were retired primarily because they failed to detect planes that were more than twenty-five miles away.
- DWilliam Sansome Tucker chose concrete as the primary construction material because it amplified the sound waves of distant engines.