GeekOut

Cloaking experiment draws comparisons to 'Harry Potter'

Researchers at the University of Texas in Dallas say they have discovered a form of "invisibility cloak," but don't think you'll have "Harry Potter" powers quite yet.

But, is it true that J.K. Rowling's fictional wizardry could become scientific fact? CNN Geek Out spoke with Dr. Ray Baughman, Director of The Alan G MacDiarmid NanoTech Institute there at UT Dallas, to find out.

CNN Geek Out: How did this experiment come about and how does it work?

Baughman: It started after Chinese researchers discovered that our carbon nanotube sheets can be used as thermo-acoustic loudspeakers. Loudspeakers of this type have been known for a long time. You heat up a material and it causes air surrounding the material to expand and you get soundwaves.

These sheets have a very low density so as a consequence it takes very low energy to heat them. They also have high thermo-conductivity.

We took these carbon-nanotube sheets underwater to make sonar projectors.

One thing that came out of all this research was that these carbon-nanotube sheets can be used as photo-thermal deflectors. You can scan light, and move it around, and this is a cheap and fast way to do it.

One of my former students, Carter Haines, discovered that if you move a laser across these sheets, you get different sounds depending on how fast the laser goes. The laser beam is deflected.

In this case, you’re seeing it by light. So we started out looking at the behavior of the materials and found a mirage effect, like when sometimes, you look at something from a distance it looks like a puddle of water. What’s happening is you have a very low angle of observation with respect to the road. When you’re looking at this “puddle,” you’re really looking at the sky.

I was at this global climate project at Stanford University, and I saw this wall in front of this beautiful patio, and there’s this garbage can. And I said, “Well, we could really cloak that. We could deflect the light so what you saw was the wall behind the garbage can.”

In “Harry Potter” and “Fellowship of the Ring,” the light goes around the material and cloaks the object. In our version, this brick wall continues on both sides of the garbage can. The wall doesn’t go on behind the garbage can but it would look like you’re seeing it.

It was actually fairly late in research that comparisons to these movies came up.

CNN Geek Out: How long did all of this research take?

Baughman: About nine months including revisions to the paper and so forth. We move fast.

CNN Geek Out: Was there a lot of excitement when this discovery was made, did you have a big ‘Eureka’ moment?

Baughman: The paper was originally titled ‘The Mirage Effect’ before we saw anything. It’s one thing to see a light being deflected, that’s nice. But to actually see something disappear, now that grabs your attention.

CNN Geek Out: Was there a pretty immediate reaction from the world at large?

Baughman: This only happened within a couple of days. Half a million viewed the video within a couple of days. This news flurry really took me by surprise.

CNN Geek Out: Could someone conceivably put on an “invisibility cloak?”

Baughman: It’s nice to excite the imagination but we’re far from doing that. The temperature dependence of the refractive index which determines the speed of light is much bigger in liquids than in air. So there underwater, right in front of you, you can see things disappear. The most immediate application is thermal deflection. But if the person were in the ocean, they could disappear underwater. But they don’t really disappear in that sense, because a cloak is being heated up. So if a person had an infrared camera, they could still see them.