The counter-illumination, inspired by abysmal fish, was experienced on military planes and ships before the development of modern radar
Curious to think that technology “Stealth”the science of mimetization in the military field, something must animal kingdom. Yet, scrolling through the history of the techniques of camouflage of planes and shipsyou get to ocean depth. It is known as many Fish and molluscsto escape or to attack predators and prey, have developed incredible mimetic skills.
One in particular was the basis of the experiments of counter-illumination applied to aircraft and wars ships between the 1930s and 1940s. In some marine species the camouflage capacity has developed as “Isoluminance”that is, the faculty to imitate the light that filters from the marine surface to get confused with the surrounding environment. A cuttlefish of the Pacific, the Watsenia Scintillansis able to camouflage through counter-lighting thanks to photojobs present on the body surface, whose luminescence perfectly imitates the light filtered by the sea, making the small sepia invisible if seen from the bottom.
The counter-illumination was studied between the two wars first by Canadian navy and later fromUS aeronauticsin particular for the hunt for submarinesas a delayed identification of the huntbombarders would have made the immersion maneuvers more difficult by increasing their vulnerability. As for ships, imitating the light of the horizon would allow a greater approach to objectives and delayed the action of batteries or enemy boats.
The experimentation of counter-illumination from the 1910s to Vietnam
The first experimentation on a plane took place even before the military authorities were interested in the counter-illumination and was carried out by a woman, Mary Taylor Brush. Artist and pilot, friend of Amelia Earhartwas the first to apply a series of bulbs to the canvas of the wings of its single -seater to make its little one invisible Morane Borel Thanks to the imitation of natural light. Brush experiments ended up with a flight in the sky of Long Island, New York. These were the years of the Great War but the solution was never used in air combat.
The interest in the counter-lighting resumed in the thirtiesinitially work of the Royal Canadian Navy who tested it in 1940 on HMS “Largs” Through the application of photo -oriented photos to change the lighting of the vessel surface. The United States followed with theMarina aviation In 1943 to apply the experimental counter-illumination to hunting and bombers in the fight against submarines U-Boot.
The name “Yehudi lights” He was born from a popular catchphrase in vogue at the time, derived from the name of the famous violinist Yehudi Menhuin During a radio program of Bob Hope. The expression «Who’s Yehudi?“He became synonymous with a” known but not visible “person.
There US Navy experienced an evolution of what has already been tried by the Canadians, with the application of adjustable and adjustable lights on the wing surfaces and on the engine coat of the planes. At the end of 1943 a wooden reproduction of the bomber Consolidated B-24 Liberator It was equipped with Yehudi lights and hanging on air cables a Oyster Bay, Long Island. It was shown that the shape of the plane, properly counter-illuminated, he completely disappeared in certain light conditions.
The experiment was repeated on Cacciabombardieri Grumman Tbf Avengeraerosiluents that were equipped with Yehudi lights whose intensity was automatically regulated by external sensors. The results were comfortingsince they greatly reduced the visibility of the Aereo approaching – from an average of 19 km less than 3 km – allowing the attacker aircraft to earn time on the maneuvers of the submarines. However, the experiment was never applied on a large scale: the Radar technologyquickly evolved during the conflict, made the Yehudi an effective solution but non -decisive. Also, a few months after the last tests, The war ended.
But Not the story of the counter-illuminationwhich was reconsidered several times after the war. During the Conflict in Vietnamsome fighter -bombers F-4 Phantom they were equipped with Yehudi lights to reduce visibility in a aircraft notoriously distinguishable also for the long trail who left behind him. Also in this case one was recorded one reduction of visibility of about 30%.
