Can we become invisible?

We all love the idea of being able to creep around, watching people without them knowing, eavesdropping on conversations. Think of all the fun you could have if, at the snap of a finger, you could become invisible.

Lots of books and movies have featured people who deliberately or accidentally became invisible, such as The Invisible Man and Harry Potter. In some stories, experiments with chemicals and nuclear explosions have made fictional characters become see-through.

Real-life invisibility

‘Stealth’ aircraft have radar-absorbing panels and are painted with a special coating. This deflects radar signals up or down, rather than back to the radar-detecting instrument, making it harder for the radar to detect objects.

A team from the University of Singapore has developed an invisibility gun. It makes things invisible by bathing them in a beam of darkness. Using a laser and a special lens, the researchers have used the darkness beam to hide a tiny three-dimensional model of the letter ‘N’. The method works only with small objects, so the challenge for the researchers will be scaling it up to the size of a person – if they really want it to catch on.

An English company has used tiny carbon tubes called nanotubes, each 10 000 times thinner than a human hair, to make a material they claim is blacker than black. The material captures 99.96 per cent of the light that hits it. When coated onto aluminium foil, it makes the foil almost impossible to see. ‘It’s like black, like a hole, like there’s nothing there,’ says a company spokesperson.

A nanotube material called Vantablack will be used in astronomical cameras and telescopes to reduce the reflections from stray light. This will let astronomers spot faint stars. If you could make a shirt from Vantablack, it would appear as if your head was floating in mid air, with your hands suspended nearby. Could this be just like the Harry Potter cloak of invisibility?

For more on this and 41 other inventions of the future, check out our book, Imagining the Future: Invisibility, Immortality and 40 Other Incredible Ideas, by Simon Torok and Paul Holper (CSIRO Publishing), www.publish.csiro.au/pid/7344.htm.