In times past I have seen a few of these sort of cup shaped things in some of the countryside's across britain, be it sat on a train or in a car, I have always wondered what they were, and about a year ago found out that they are something called a sound mirror. A sound mirror is a passive device used to reflect and... perhaps to focus (concentrate) sound waves. Prior to World War II and the invention of radar, acoustic mirrors were built as early warning devices around the coasts of Great Britain, with the aim of detecting airborne invasions. Nowadays they are not used however have the same effect as whispering dishes, which are also pretty cool.
2.07.2011
SOUND MIRROR
In times past I have seen a few of these sort of cup shaped things in some of the countryside's across britain, be it sat on a train or in a car, I have always wondered what they were, and about a year ago found out that they are something called a sound mirror. A sound mirror is a passive device used to reflect and... perhaps to focus (concentrate) sound waves. Prior to World War II and the invention of radar, acoustic mirrors were built as early warning devices around the coasts of Great Britain, with the aim of detecting airborne invasions. Nowadays they are not used however have the same effect as whispering dishes, which are also pretty cool.