Invisibility has been one of the finest ingredients for wide range of novels and films, from Star trek to Harry potter, from the Invisible man to Lord of the rings and so on. How can one ‘cloak’ or ‘obscure’ an object or even people from an observer’s field of sight? Trying to make invisibility a real phenomenon rather than a myth would have been just hilarious if tried in the early eras of classical physics (Newtonian physics) dominance.
Maxwell’s discovery of light’s basic property, which depicted light as an ‘electromagnetic disturbance‘ helped shape the scientific world’s understanding of the laws of optics. One can easily infer from light’s fundamental property that invisibility happens at the atomic level of the matter Maxwell’s equations so it is exceedingly difficult if not impossible to accomplish , “To make Harry Potter invisible, one would have to liquefy him, boil him to create steam, crystallize him, heat him again, and then cool him, all of which would be quite difficult to accomplish, even for a wizard”.
So the question arises is it really possible to render an object truly invisible? The answer to this question is highly dependent on a group of “exotic materials” called Meta-materials. What are these so called “Meta-materials”? “They are substances that have optical properties not found in nature. Meta materials are created by embedding tiny implants within a substance that force electromagnetic waves to bend in unorthodox ways. Think about the way a river flows around a boulder. Because the water quickly wraps around the boulder, the presence of the boulder has been washed out downstream”. Similarly, meta materials can continuously alter and bend the path of microwaves so that they flow around a cylinder”, and nowadays it is made for visible light spectrum nowadays other method to achieve invisibility are being developed like the one below.
One of the recent breakthroughs in 2019 was the development of an invisible tech called “Quantum stealth” developed by Hyperstealth,a Canadian camouflage design company, the material is as thin as paper, inexpensive and requires no power source. Moreover does it not only bend visible light but also works for uv, infrared and shortwave infrared achieving “broadband Invisibility cloak”, and “ The material uses lenticular lenses which you see in 3D books and dvd covers and movie posters where by moving side to side you get a 3d image” said Guy Cramer , president and CEO of hyperstealth to CTV News channel “we ‘re using the same material and we’ve removed the picture from behind it to get that effect” The physics is based on the principle is based on Snell’s law. Every material has a refractive index, when light moves between materials its angle changes depending on the refractive index of the material so by constructing a material with blind spot,we can make a leap into the invisible.