Real invisibility cloak, quantum teleportation: How Harry Potter influences physics research. – Slate Magazine


Invisibility cloaks seem to be an enduring staple of science fiction and fantasy. When I was growing up, this was most evident in Star Trek. For the last decade or so, it’s been Harry Potter. The allure is not surprising—I expect that everyone has had a fantasy, at some time or another, about being invisible. Whether the motivation is to get a free peep show or escape out of, or into, dangerous situations, the freedom offered by disappearing into the background is compelling. The real question, of course, is: Will it ever be possible?

Alas, no. In the first place, even if you could be invisible, it wouldn’t be all it is cracked up to be. It is a simple law of physics that interactions are two-way streets, so if you are invisible because nothing interacts with you, then alas, you wouldn’t be able to see—your retina would not intercept light. So there goes all the fun.

But more important, perhaps, the particles that make us up do interact with electromagnetic radiation—which means that while we can camouflage objects, we cannot make them transparent to all forms of radiation. We might hide them in the microwave, or infrared, or even visible by exploiting the wave nature of light, either causing the waves to bend around objects or by causing waves that scatter off the object to interfere with each other, effectively canceling each other out. But since this technological wizardry is usually tailored to the wavelength in question, then waves of vastly different wavelengths, like X-rays, for example, might still scatter off of them.

Nevertheless, since I first wrote The Physics of Star Trek in 1995, the lure of invisibility cloaks has continued to motivate creative scientists, and several remarkable advances have taken place in finding new ways to literally make objects invisible, at least to certain frequencies of radiation. When announcing new research in this field, shrewd communications officials from universities and laboratories have, over the last several years, taken to referring to Harry Potter in their press releases announcing cloaks for buildings, shields for microscopic objects, and more. In recent weeks, the University of Texas–Austin generated lots of headlines withthis press release.

Written By: Lawrence Krauss
continue to source article at


  1. Active adaptive camouflage is already being tested by the military using an octopus or chamaelian like system to change the colour of spot-like panels. . It uses about 1000 hexagonal panels to cover the sides of a tank. This 1min18 sec video shows this.

    In nature, there are quite a lot of deep-sea creatures which are transparent or partly transparent in water!

  2. Even if you retinas (or even your eyes) were visible but the rest of you invisible, that would be a serious stealth advantage.

    Similarly to the invisibility problem in space. You don’t have to be completely cold. You just have to look like background noise.

  3. In reply to #3 by rjohn19:

    I turned 66 last month. I am not famous. How much more invisible do I need to be?

    I can see your posts!

  4. Lord of The Rings brought the invisible cloak into my childhood, never read a word of Harry Potter. I would play D&D with my brother and friends back then. We invented funny magic items as a lark. I had a +6 very loud cloak of invisibility. No one could see you but they could hear you breathing the minute you put it on.

Leave a Reply