The Art of Invisibility: Nature and Cutting-Edge Technologies

A medieval mage stands before a mirror, thoughtfully rubbing his eye with a ball of dung mixed with a drop of olive oil. It’s unlikely he’s aiming for conjunctivitis — he craves invisibility! This is how our ancestors dreamed of escaping pesky neighbors and hated barbarians. Sadly, no records remain of how this simple concoction actually worked.

Invisibility cloaks, magic hoods, rings of power with the “mind control” feature — all well-hidden secrets from the familiar realms of physics, yet irresistibly fascinating! Advanced camouflage hardly surprises anyone anymore. It works effectively but sounds far less mystical than “grind up an owl’s eye.”

While humans dream of becoming invisible, nature has long perfected this trick, offering its own solution: mimicry of color or form. For some creatures, it’s about sharpening their hunting skills; for others, it’s a matter of avoiding becoming someone else’s meal.

True masters of disguise hide beneath green lily pads, blend into tree bark, mimic a dry twig, or slip unnoticed into a snowy blanket to escape a hungry predator.

Take, for instance, an extraordinary creature from the depths of the ocean — Vitreledonella richardi, the Glass Octopus. Its long, pointed body resembles jelly, and its lack of coloration suggests it was simply forgotten in the coloring process. This marvel can instantly change its color and even shape depending on the situation. Essentially, a chameleon under the sea!

Mimicry is impressive, but it doesn’t suit every situation. If there’s a crowd watching, someone is bound to spot the “invisible” one. That’s the main drawback — mimicry only conceals by blending into the surroundings, while true invisibility neither reflects nor absorbs radiation. (Ah, beautifully put!) Meanwhile, somewhere in the transparent waters of the ocean, the glass octopus fights its own battle for survival or perhaps plots a world takeover.

But back to reality.

Imagine life as a mix between an action movie and a comedy series, starring ordinary people with newfound abilities to become invisible. Sometimes reality throws us into situations where even we don’t understand how we ended up playing the role of a ghost. Your jacket is bright, your hair’s all over the place — and yet, somehow, nobody sees you. 

Who would have thought that a store could act like a black hole, swallowing people along with their desires? The people around you, like certified ignorers, don’t notice anyone, even as you desperately try to make eye contact with at least the cashier. But the cashier seems lost in thought, either pondering the meaning of life or that same glass octopus, stubbornly refusing to notice you. You could yell, “Hey, I’m here too!” But alas, ghosts have no voice — no matter how much you shout, no one will hear you!

You attend an important event only to realize your charm has gone on vacation. People are chatting, laughing, while you quietly roam the corners, dreaming of sneaking over to the snacks. You create a post that you’re sure will break the internet. Instead, it gathers just a couple of likes — one from your grandma and one from a neighbor who has a soft spot for you. Algorithms seem to have decided you don’t exist, turning you into an invisible entity for your audience.

And in relationships? Beside your partner, you feel like part of the background scenery, making daily attempts to get noticed. What about in work chats? Or at the parking lot?

It turns out invisibility is, in fact, something quite achievable. It’s present in every moment when we feel out of place. So why not use such invisibility wisely? At least to quietly finish your meal without worrying about judgmental stares.

But if you think about it, the life of an invisible person isn’t all that great.

People don’t like anyone who is different from them or feels threatening. And an invisible person is exactly that. Who knows what to expect from them? People will either try to destroy them or lock them up in a lab, forcing them to always hide and live in fear.

What’s more, unless they manage to make their clothes invisible too, they’d have to walk around naked. Put on a hat? You’re exposed. Injure your foot? Forget about bandages, and blood would likely be visible too. Even eating becomes an ordeal — whatever you eat or drink remains visible until it’s digested. Better hide while you digest.

On snow or mud, your footprints are still clearly visible. There’s also a significant risk of being hit by a vehicle — the driver can’t see you, after all, so you’d have to move cautiously. And while invisible, you may not be seen, but you can still be heard. Animals can also smell you perfectly well.

Sleeping is tough for an invisible person, as light would pass right through their closed eyelids. Scientifically speaking, an invisible person should be blind anyway since light wouldn’t refract in their eyes but would pass straight through. On top of that, the retina of the eye might appear floating in mid-air, which would surely attract attention. Let’s face it, making friends while invisible isn’t easy.

And inevitably, someone will accidentally splash paint on the invisible person.

Any unexplored technology makes scientists frown and scratch their heads, and invisibility technology is no exception.

Inspired by natural masters of disguise like chameleons and octopuses, a team of Chinese researchers developed a material called Self-Adaptive Photochromism (SAP), which can turn a person or any object into a true ghost. Forget about heavy and expensive camouflage technologies requiring laboratories and testing grounds. SAP is like a carpet — lightweight, accessible, and incredibly stylish. The unique molecular structure of this material allows it to adapt to its surroundings.

Scientists observed that under the influence of light, the material’s molecules change their configuration, leading to a color shift. In darkness, SAP remains black, but once exposed to sunlight, it starts transforming like a tipsy guest at a party. With such a material, you can blend into any landscape and maybe even catch the attention of local wildlife.

But that’s not all. Recently, Japanese engineers introduced a “hat” capable of virtually erasing the echo-location signature of an object. Here it is, the long-awaited dream hat! It turns out that hiding not only from prying eyes but also from sonar is entirely possible.

Researcher Amanda D. Hanford from Penn State University, along with her team, developed a cloaking device that forces sound waves to bypass objects, even underwater. The sound waves don’t reflect off the cloaking material, making any object almost invisible to sonar. Underwater objects simply vanish from radars. However, the catch is that for this metamaterial to work, its cell size must be smaller than the sound wave’s wavelength. So, if you’re dreaming of making your scuba diving backpack invisible to sensors, you’ll need to work on its size.

The technology is still under development, and objects don’t yet become entirely invisible, but they are already nearly undetectable underwater.

If you’re looking to become invisible on land, a material developed by the Canadian company Hyperstealth might be the answer.

The top-secret fabric is called Quantum Stealth. It’s a true trickster material that bends light around itself, making it seem like the object you’re looking at simply isn’t there! And it doesn’t require a power source. This fabric works without any gimmicks — no cameras, batteries, or mirrors.

For now, this material is intended for military use, with the Canadian, American, and British armies already testing it. However, Hyperstealth has announced a commercial version of their invisibility cloak called Hyperstealth INVISIB. While it won’t be as impressive as its military counterpart, it will still let you play a little game of “disappearing.” The company is currently securing rights for mass production, and we may soon see this wonder material on store shelves.

Meanwhile, scientists at the University of Texas in Dallas have developed an invisibility technology based on carbon nanotubes. Instead of a magic wand, they use cylindrical carbon molecules with high thermal conductivity to create a mirage effect.

It’s all about photothermal refraction.

It sounds complex, but in reality, it’s just a game of temperature. Scientists turn the current on and off, heating and cooling the material, and as a result, the object behind it becomes barely visible. However, for this to work, the concealed object must be placed in a container filled with water.

Physicists from Birmingham decided to harness crystals and began experimenting with silicon nitride on a transparent nanoporous substrate. Their efforts resulted in an optical mirror with nanometer-sized holes that can hide objects in the visible spectrum.

Researchers at Cornell University joined the race, crafting a “nano-sized” guitar out of silicon. This six-string guitar is so tiny that if you lose it, it will vanish. The only way to find it is with a magnifying glass. And here’s the most fascinating part — you can play this invisible guitar, but you’ll need an atomic force microscope. The frequencies the guitar emits, however, are beyond the audible range. Still, what a breakthrough in invisibility!

It turns out entire buildings can disappear.

Imagine walking down the streets of Seoul, turning your head up, and the skyscraper where you just rented an apartment has vanished. This isn’t a test of your sanity but the latest trend in architectural fashion by the American firm GDS. Engineers and architects decided buildings sometimes need to be invisible too, so they incorporated concrete, glass, optical video cameras, and displays into the construction.

Cameras on the facade capture what’s happening behind the building and project it onto the walls, creating the illusion that the building doesn’t exist. Admittedly, at the corners where the displays meet, the skyscraper may still be slightly visible, but as flexible displays improve, they will be able to wrap around protruding edges. It’s an exciting but risky idea. After all, one could accidentally bump into a seemingly “nonexistent” building.

Scientists from the University of California and Duke University turned their attention to squids. If squids can hide from predators, why can’t marines wear “invisibility cloaks”? To achieve this, researchers studied reflectin, a protein found in squid skin. This protein can change color depending on the light.

By manipulating the spacing between layers of their cells, squids can reflect light of different wavelengths, much like a skilled artist adjusting their palette. Scientists extracted this protein and applied it to special films, then treated it with water vapor and acid. The result was a layer capable of changing color. It seems the first step toward creating an invisibility cloak has been taken.

And speaking of surprises, the world of technology is full of them.

Researchers from the University of Extremadura developed a method that grants objects electromagnetic invisibility. According to EurekAlert!, this incredible plasma cloaking technology hides objects from sight, making them invisible to light by preventing them from reflecting it or casting shadows.

How does it work? Instead of covering objects with layers of complex coatings, scientists propose filling components with special materials that have high dielectric and magnetic properties.

For now, this method is suitable only for small objects, like military aircraft. But the researchers have big plans for the future, confident that their invention has enormous potential for further development.

When it comes to becoming invisible, it’s not as simple as it seems.

If a body doesn’t reflect, refract, or absorb light, unfortunately, invisibility is out of reach. Skeptical? Try throwing a piece of ordinary glass into water — it becomes almost invisible. Light passing from water to glass behaves like a soldier on parade — calm, orderly, and hardly reflecting or refracting at all.

To become invisible, you would have to reduce the refractive index of all the tissues in your body — skin, muscles, internal organs, and bones — to the level of air. And here’s where science says “no.” Physics and physiology have no idea how to make this possible. Invisible eyes wouldn’t be able to capture light, and altering the optical properties of tissues would require such a radical metabolic overhaul that it’s unclear how one could survive it.

As for the invisibility cloak itself, it faces its own set of challenges. It would need to adjust the optical properties of living tissues, clothing, shoes, and anything else you’re wearing. Now think about the materials your clothes are made of — synthetics and other scientific marvels. Case closed.

Some experts believe that integrating invisibility into everyday life is just a matter of years — or at most, decades.

In the meantime, why not embrace being visible? The world is full of fascinating people and events worth noticing.