We’ve all been there, you know… those times when we would love to disappear. This happens in many situations, such as a lecture from parents about responsibilities or awkward small talk with strangers at parties. Or, perhaps at the completely opposite part of the spectrum, such as wanting to know what the boss really thinks about you behind closed doors, or what your date really thought of your hilarious story when she tells her friends about it later!
What if invisibility was really possible? First of all, sign me up!
Imagine just throwing on your magical garment and vanishing in the blink of an eye. This incredible fashion concept has become ludicrously common in the world of science fiction and fantasy. Everyone from boy wizard Harry Potter to intergalactic hunters have at least one invisible garment in their wardrobe. That being said, where does this leave us – the mere mortals?
Well, lucky for us, scientists have taken major strides to transform invisibility from fiction to fact. Although the Harry Potter cloak remains an implausible dream, research into invisibility has had some major breakthroughs recently.
How Does This Work?
The science of invisibility combines two of physics’ greatest concepts: Einstein’s general relativity and Maxwell’s principle of electromagnetism.
To become invisible, an object must do two things: it must be able to bend light around itself, so that it casts no shadow, and it must produce no reflection. The first factor is related to the idea of “transformation optics” – the ability to bend light around a region of space to make it look as if it weren’t there.
While naturally occurring materials are unable to do this, a new class of materials called metamaterials is now making this possible. Synthetic substances with optical properties that are unknown in nature can now be designed to achieve this goal.
These structures are made up of lattice with spacing between elements that are less than the wavelength of light we wish to bend. If properly constructed, these materials guide rays of light around an object – much like a rock diverting water in a stream. For now, however, the technology only works in two dimensions and only comes in the ultra-petite size of 10 micrometers.
Let There Be light!
Light is a form of electromagnetic radiation, composed of perpendicular vibrations of electric and magnetic fields. Natural materials only affect the electric components, while metamaterials can affect the magnetic component too, expanding the range of possible interactions.
Artificial materials, which have so much more flexibility, have allowed this idea to move forward in a major way. As such, progress continues to be made. These metamaterial and calcite techniques could see real-world applications soon, with the former preventing antennas from interfering with each other, for example.
This is a simple idea with impressive results, and one that might end up being used in the near future. However, due to its unique properties, we may never see it coming!
In the meantime, we’ll have to keep our invisible men limited to our sci-fi and fantasy movies on the silver screen.