The power of invisibility is one that I have always found to be fascinating, there are many things you could do if you were invisible. The idea of being able to bring this power to life is mind-boggling. The second post of this series will cover invisibility and how scientists are taking us one step closer to being unseen. Superheroes and popular characters like Violet Parr, Harry Potter, and Randall Boggs were capable of invisibility through their unique methods. Things like natural-born powers, invisibility capes, and monster abilities, are methods that are not capable of being replicated by science… at least not yet. The method we will cover here boils down to the basics of how we see things, the way our eyes perceive light. Scientists are playing around with light bending and optics to make objects “disappear”.
How Do We See?
To understand invisibility, we must first understand what it means for us to see an object. The process of seeing begins with light. When you see an object, what you are seeing is the light reflecting off that object and entering into your eyes. To make an object invisible, this fundamental interaction with light must be altered. More specifically, the light rays would need to be bent or diverted around/away from the object, preventing them from reaching the eyes and therefore making it unperceivable to the eyes (Lo, 2018).
Metamaterials
Scientists are creating metamaterials, which are “artificial materials with the ability to control physical phenomena” (Lo, 2018). With these materials, scientists can control and manipulate light rays, helping create invisibility. This process, known as light bending, is a key component in invisibility cloaks. This is further explained by scientists who state, “Metamaterials are composites designed to have a negative index of refraction, which imparts the extraordinary capability to bend light away from or around an object made from or coated with the material” (“Metamaterials Bend Light to New Levels,” 2023b). Despite the challenges in scaling these technologies, the progress in metamaterial research could revolutionize how we interact with the physical world and lead to advancements in various scientific fields.
Challenges
There are two main challenges when trying to reach full invisibility, size and range. Unfortunately, the invisibility effect isn’t as broad as one might hope. Researchers have only managed to develop metamaterials that function with a single wavelength of light, corresponding to just one color. This means the material can create invisibility in controlled settings with a single light color, but not in natural environments where multiple colors of light are present. While these invisibility cloaks are a remarkable breakthrough, they aren’t perfected for the stealth needed in real-world conditions, limiting them to certain factors. Another challenge is the size of objects. Bigger items are more difficult to manage, and current metamaterials aren’t capable of hiding something as large as the human body. While scientists are optimistic that new ideas and designs will help tackle this problem, it will likely be some time before we can reach the point of making humans fully “disappear” (Lo, 2018).
Real-World Applications
Although there are many challenges in the journey to invisibility, there are highly beneficial theoretical uses for this ability that make it all the more exciting to achieve. According to researchers, “the Rochester Cloak, for instance, could one day allow surgeons to see through their hands, preventing their hands from blocking their view of what they’re operating on” (Lo, 2018). This use could change science and the way we view healthcare completely. There are many motivations for perfecting the invisibility cloak as it could help so many in the long run.
Conclusion
Though complete invisibility remains a dream and goal for most of us, it is hard to ignore the remarkable progress scientists have made in controlling light to achieve partial invisibility. The innovation of metamaterials and spectral cloaking is bringing us closer to a future where invisibility will leave the realm of fiction and enter into reality. Although the methods are limited, they are the first steps to becoming like the superheroes we see on our screens. If this is what scientists have created so far, I cannot wait to find out what else the future holds for us.
References
Lo, A. (2018). Hidden From Plain Sight: Can Science Create Real-Life Invisibility? – Science Communication Club. Utoronto.ca. https://scc.sa.utoronto.ca/content/hidden-from-plain-sight-invisibility/
Metamaterials Bend Light To New Levels. (2023). Chemical & Engineering News, 86(33). https://doi.org/10.1038/nature07247)
