Invisibility Cloaks Are Expected to Be More Than Just Movie Props
So, you grew up with Harry Potter and you always envied the opportunities he had at the Hogwarts. All those magic, spells and fun he had. What a great chance! And when you faced the truth that Harry Potter and Hogwarts are fictional and you'll never get your invitation letter to Hogwarts, yes, you were upset. And the deathly hallows, they aren't real either! Wait a second, or are they?
What would you do if we told you that you can actually get the invisibility cloak in real life? Would you stalk your ex through their window? Would you go to the concert of your favorite musician without buying a ticket? Would you cheat during the most difficult exam of your life?
Well, it's not really important what you would do with the cloak of invisibility, but here is some good news for you; you can get the invisibility cloak in real life indeed! So rejoice dear Muggle friend, you can finally pretend that you're a student in Hogwarts. Of course, it's not about magic, it's more about... science.
Basically, the invisibility cloak is possible through the metamaterials which are artificial materials engineered to have properties that normally not found in naturally occurring materials. Metamaterials are smaller than the wavelength of light and they control the spin of light.
To make an object invisible, scientists developed metamaterials that can bend electromagnetic radiation, such as light, around an object to create the illusion that it isn't there at all.
All of the natural materials have a positive refractive index, and this affects how light waves interact with them. If you see a red apple, it's not because an apple indeed has a color, it's because the apple reflects the red light frequency of the sun. So, if the structure of any material is changed on a small enough scale, the way they refract incoming waves can be changed too.
Everything in life reaches us with waves; images via light waves and sounds via sound waves. And if you change the direction of these waves around an object, you can successfully make it invisible or inaudible.
In 2006, a group of scientists from Duke University created a simplified cloaking device. This device could only turn an object invisible from one wavelength of microwave light. However; it was proof that a real-life cloak of invisibility is possible.
A team of researchers in Montreal asserts that they successfully managed to turn an object invisible to broadband light, by using a new technique called "spectral cloaking."
Within the project of the cloak of invisibility, spectral cloaking turns the light waves into a frequency that will pass through the target object and turn the light waves to their original state. Thus, the object becomes invisible, not like disappearing from the sight with magic, but like, with a little bit of science, you just can't see what is actually there.
In this new research led by telecommunications engineer José Azaña, the device works by shifting one frequency of light to another as the light passes through the object. After the light passes, the frequency is put back in its original state.
However; the device is still in progress and has yet to address its own limitations. At the moment, spectral cloaking only works from one direction. So an observer has to stand in the path of light to not be able to see the object.
For a long time, it wasn't possible to get fully invisible, it was only possible to conceal objects by distorting the light waves to move around an object. But at the moment, there are successful attempts to create an invisibility cloak more large-scaled than before.
The spectral cloaking experiment didn't make anything such as a human or a jet invisible, but it successfully showed that light can be shifted to completely pass through an object, rather than being reflected or absorbed.
One of the biggest challenges in creating a real-life cloak has been the incorporation of a large variety of wavelengths since the material of the cloak must vary to bend and unbend the light by the proper amount. Based on the materials discovered so far, the penetration of the visible light portion of the spectrum with a cloak hasn't been managed yet.
Don't lose your hope though. The developments throughout the years for the invisibility cloak are actually pretty promising for the future of it. Technology is getting to a point that we could never imagine 10 years ago, so maybe 10 years from now, we won't be able to see anyone in the streets, because of the invisible cloaks.
You'll be able to go to the cafe you like which is next to your ex's apartment without getting dressed up. You'll be able to pass the class that you've been taking for the past 4 years. You'll be able to scare and make fun of your friends with the cloak of invisibility. Even the dream of it is fun and great, isn't it? You don't have to give up on your dreams of becoming invisible.
Maybe you don't have the opportunity of becoming fully invisible like Harry Potter at the moment, but you can use the cloaks that are in use for now and for sure you can do loads of crazy stuff with those too. You can try to do it with only one part of your body, it sounds crazy and scary, doesn't it?
And what would you do if you had the invisibility cloak? Would you use it for good purpose or a bad one? It's time to plan what you would do with it because we believe that in the near future, we'll have it!