Fans of the original, classic Star Trek will remember the “cloaking device,” a technology perfected by the warlike but technologically sophisticated Romulans, that when activated was capable of rendering an entire starship invisible.
While actual science circa 2018 may be quite some distance away from building a starship, much less rendering one invisible, a new research study published in the scientific journal Optica this week appears to show that an invisibility cloaking device may indeed soon be possible “under realistic conditions.”
The new study by scientists at the Canadian National Institute of Scientific Research in Montreal is not the first to show that the concept of invisibility cloaking can work outside of the boundaries of science fiction storytelling. But according to a summary by the site Science Daily, the NISR researchers have discovered a new, more effective invisibility technique that they call “spectral cloaking,” because it involved breaking a wave of light into all of the colors on the spectrum contained within that light wave.
The site Futurism explained the concept.
“There’s something called the electromagnetic spectrum. It contains all the different frequencies of electromagnetic radiation, a certain kind of energy. X-rays, gamma rays, and radar all fall somewhere on this spectrum,” Futurism correspondent Kristin Houser wrote. “While you can’t see an X-ray, your eyes can see one small range of frequencies on the electromagnetic spectrum. We call this visible light. As mentioned, it’s a range separated into what we perceive as colors, with violet at one end and red at the other.”
Earlier versions of invisibility cloaking relied on ways to bend light waves so they moved around an object, according to a report by the London, England, newspaper The Times. “The trouble with this approach is that it distorts the waves and struggles to cope with a range of different frequencies, such as the various colors of light,” Times science correspondent Oliver Moody explained.
The spectral cloaking method, however, alters the frequency — that is, the color — of light waves as they pass through objects. Normally, objects are visible to the eye because they reflect certain frequencies of light. A spectral cloaking device, however, changes “blocked,” or reflected, colors into a range of different colors on the wave’s spectrum, according to a summary of the findings appearing in R&D Magazine.
As a result, the light wave passes through an object without being blocked — meaning that the light would not be reflected back to human eyes, rendering the object invisible. The device then reassembles the light wave into its original frequency when it comes out the other side of the now-invisible object.
“Our work represents a breakthrough in the quest for invisibility cloaking,” said researcher José Azaña, one of the authors of the research paper, quoted by Science Daily. “We have made a target object fully invisible to observation under realistic broadband illumination by propagating the illumination wave through the object with no detectable distortion, exactly as if the object and cloak were not present.”
While rendering giant starships invisible may not exactly be right around the corner, the researchers say that spectral cloaking may have practical uses in such areas as online security. The cloaking device could be used to shield data passing through fiber-optic cables, preventing spies and other eavesdroppers from intercepting conversations and internet exchanges — because the data itself would become “invisible.”