|
Mission
Invisible
I can easily imagine
the things I could do if I had an invisibility cloak.
However, the only solid objects I have ever seen
disappear are the Statue of Liberty* and one quick-footed blind date. Soon, thanks to new materials and
fabrication techniques, we may all get a glimpse at
the invisible.
A
team led by scientists at Duke University's Pratt
School of Engineering has demonstrated the first
working "invisibility cloak.".
The invisibility cloak uses metamaterials.
Metamaterials are blends of man-made composites that
exhibit properties not found in nature.
Making an Invisibility Cloak
To make an invisibility
cloak, surround an object with metamaterials (the
outer shell in the image below). Assemble the
metamaterials in precisely the right fashion and light
waves that pass through the metamaterials will bend
around the object, like water flowing undisturbed
around a rock.
The Real Trick
Light and other
electromagnetic waves typically travel in a straight
line, taking the shortest path between two points.
Only a fair amount of gravity, like that from The Sun
or a black hole, have been proven to alter that path.
It would be extraordinary if scientists could achieve
the same effect in the lab using man-made materials.
How
will this technology be used?
Many practical uses
exist for materials that can precisely control the
paths of light, sound and harmful radiation. There are
just as many sinister applications that come to mind
for a cloaking device.
The Invisibility Cloak
is another impossible product made possible by rapidly
advancing technologies and a better understanding of
our universe. It would benefit the public to readily
address the social impact of invisibility before it
materializes in real applications.
* Making
the Statue of Liberty disappear on live television in
1983 is one of
David Copperfield's most remembered tricks. The
illusion was a creation of
Jim Steinmeyer and is still a closely guarded
secret.
Wormholes on
Earth?
According to a group of mathematicians,
it may be possible to create devices with internal tunnels
that are invisible to detection by electromagnetic
waves--wormholes, in a sense.
|
