5 Ways To Become Invisible

In order to see something, the object either needs to emit light directly like the sun or a bulb or else light has to be reflected from an object into our eyes. An object will be invisible when it is not perceivable by the eye. For this to be possible either light ray should not enter the eye or even if they enter we should not be able to sense it. There are some scientific possibilities to become invisible. Although there are limitations in every process but there are really some promising and useful ways in the term of invisibility. Few possibilities are discussed below:

1. Move at great speed: 

There are few theories that say that an object can turn invisible when it travels at a speed greater than that of light because light cannot catch up with it. But Einstein’s special theory of relativity says that we need infinite amount of energy to get an object to reach the speed of light. This is not practically possible. What if we can make an object move at a very fast velocity but less than that of light so that we can’t see it? If we see the example of a bullet, when a bullet is fired off the gun, it becomes invisible because it is travelling at a great speed. Now, we understand that a bullet can become invisible. So, can a human become invisible in the same process?

To become invisible one must run so fast which will be practically impossible. There is no such technology invented so far that can move a human being at a great speed to become invisible. The speed should be approximately 12 times faster than a F1 car and the angling of the eye should be limited.

2. Bending of light: 

Here we try to take light pass it around an object as if it weren’t there. Just like a light from light source suddenly bends and passes the object and doesn’t fall on the object. In this process the object would be invisible. This is very simple in theoretical way but very complex in the practical way. To make this theory work, we need to make a setup. This setup should have reflectors which would reflect the background of the object into eyes. So, the object inside the setup would go invisible and only the background will be visible. But there is a limitation, the object or human inside the setup cannot see anything outside the setup. So, this process can be used only to hide something.

3. The invisible ink: 

A red colored object appears red because it absorbs all colors and reflect only red. So does every color. Only rays having a wavelength of 380-740 nanometers can be perceived by the human eye. What do infrared colored object looks like? Would they be invisible? If we paint a human with red ink, he will look red. But what if we paint him with an infrared paint? Would he be really invisible? No. As the infrared ink absorbs all colors except infrared it turns out that it absorbs all colors in the visible range. So, the paint will be perceived as black but not visible. Invisibility is not about absorbing the light but we should be able to see what is behind the object.

4. Using cameras and displays: 

In this process a camera captures the background of an object and projects it onto a screen creating an invisible region. If you look at the screen from a different direction you'll understand that this is only a projection. So, to make it look more real we have to track the eye of the observer and change the display screen accordingly. But if there are two people, there system would be failed.

5. Metamaterials: 

Scientists have developed an invisible cloak which can bend electromagnetic radiation around an object and it is known as Metamaterials. Metamaterials can bend light around an object, giving the appearance that it isn't there at all. But this technique only worked with microwave light so far. Scientists are trying to develop the concept to make it work with visible lights too. The invisible cloak is generally made out of silk. Materials are developed to bend light so that eyes can see what lies behind the object and make the object disappear.