How do you make Invisible Ships, Planes & Tanks?

To the ancient Greeks it was called the Helm of Hades or the cap of Hades a special helmet that would make the wearer invisible. In Welsh and Germanic folklore as well as are all modern-day fictional equivalent of Harry Potter there is the cloak of invisibility, a magical item that can also make the wearer invisible so it would only seem right that the military has been striving to create its own version of invisibility as long as we've had camouflage but other than painting your face green and brown and wearing grass on your head, what else has been done to make the military invisible. Do you remember the film the Philadelphia Experiment well just in case you haven't seen it it's about a world war two experiment to make a US Navy destroyer, the USS Eldridge invisible though in the film the field generator they use makes the ship disappear and move through space and time and when it comes back strange things have happened at a crew. Well the basis of the film is actually true to make a ship invisible but not so as you couldn't see it but invisible magnetically so that it wouldn't trigger magnetic mines. This technique is known as Degaussing, effectively demagnetizing after the unit of magnetism called the Gauss. During World War 2 the Germans used magnetic mines which detected an increase in the Earth's north magnetic field when a ship passed over it, this was causing havoc with the British fleet in the North Sea in the English Channel. In 1939 after recovering a mine accidentally dropped on mudflats at low tide off of the southeast coast of England, the British were able to work out how the mines worked and then developed methods to reduce the magnetic effect. that the ships had. To degauss or demagnetize the biggest ships, giant coils of wire were fitted around their perimeters on things like aircraft carriers and troop carriers and several thousand amps passed through them. This was powered by the ship's generators like a giant electromagnet and he added a slight south magnetic bias which offset the magnetic effect of a ship near the mines. This had its limitations as it could only be used on the biggest ships of enough electrical power to run it and also where in the world it would be used because the Earth's magnetic field varies in strength in different locations, it would also need to be reversed if it were to be used in the southern hemisphere for example. Over time the mines became more sophisticated so today the latest degaussing systems can match the magnetic field of a ship to background magnetic field anywhere in the world effectively making it magnetically invisible. Now whilst this help protect the ships against mines ships could still be seen by their biggest threat submarines. During the first world war a technique of painting large abstract lines shapes and contrasting colors over ships was developed called dazzle camouflage and the ship's gained the nickname of dazzle ships or razzle dazzle in the US. Now you may be wondering why you would make a grey ship in the grey North Atlantic standout with these massive abstract patterns but these were not to hide the ship these confusing markings were to make it difficult for submarine commanders to work out the ships type, heading and speed. From side on they helped disguise the shape by which the ships could be identified and from oblique angles you can see what it makes it harder to work out which end is which and thus the ships heading. This was to try and make the Germans get their torpedo firing positions wrong so they would miss the ships. In World War one and World War two over six thousand allied warships used these dazzle patterns with each pattern being different. The problem was that because everyone was different they couldn't tell which patterns worked well and which didn't and as World War two progressed advances using planes and radar made dazzle ships less relevant. Now the main enemy of a convoy of ships was the u-boats and in World War two Allied planes were used to find and attack submarines whilst they were still on the surface but the u-boat crews could often see the planes approaching by the dark silhouettes against the lighter sky and this gave them time to dive before the planes could engage. In 1943 the US Navy tried out a technique which had been developed by the Canadian Navy called diffused lighting camouflage. The US Navy created project Yehudi this used lights similar to sealed beam car headlights mounted on the front of the plane along the leading edges on the wings these were automatically controlled by a photocell so that the brightness of the lights matched that of the sky behind the plane this apparently simple idea made the plane blend into the sky by breaking up the dark silhouette. The idea was refined and in 1945 tests with a grumman Avenger showed that it was able to get within 2.7 kilometers of the target ship without being detected whereas without the Yehudi lights it was visible 19 kilometers away. Although these worked well by the time of the end of the war radar had made the Yehudi light system pretty much redundant but that didn't mean to say that it was a bad idea, in fact it's being the basis of many ideas to apparently bend light around an object to make it appear invisible. The most notable of these is adaptive camouflage which has only really been possible in recent years with new electrochromatic materials and flexible OLED displays. The principle is similar to the Yehudi lights but instead of using a photocell they use a camera on the opposite side of the vehicle to which it has been seen and this displays the image of what the camera is seeing onto the watched side so effectively you don't see the vehicle itself you just see what you would see if it wasn't there. Now close-up this wouldn't fool anyone but from far away it can help it blend into the background. Now whilst this might work for visible light most weapons use infrared or heat to lock on to their target so the latest active camouflage uses thermo-electric panels. The system called adaptiv by BEA Systems has about a thousand or so of these small hexagonal panels also known as Peltier panels which can be heated or cooled by applying an electric current to them. Infrared cameras pick up the background infrared radiation and relay this to the Peltier panels to effectively hide the vehicle's infrared signature from weapons or enemy spotters by matching background infrared levels. As the sides the vehicle are effectively now one large infrared display the shape of another object can be projected onto it like in this example where the silhouette of a tank is made to look like that of a car it could even flash text messages which would only be seen in infrared. Now this isn't the full invisibility as we have seen in the movies but we are getting closer to approximating it although you do have to say with what we know of current technologies bending light around an object is going to take some serious science which brings us onto our sponsor for this video because if you are interested in science then you should check out brilliant. 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Channel: Curious Droid

Views: 171,299

Rating: 4.9476347 out of 5

Keywords: military vehicles, dazzle ships ww1, dazzle ships images, adaptive camouflage, the philadelphia experiment, adaptive camouflage technology, paul shillito, curious droid, invisibility cloak military, hades helm of darkness, yehudi lights, u-boats ww2, u-boats in the atlantic ww2, uss eldridge, bae systems, adaptiv camouflage, adaptive camouflage clothing

Id: DvJ_OsOxXgs

Length: 8min 46sec (526 seconds)

Published: Mon Dec 03 2018