Take a quart of metamaterials, add a heaping spoonful of left-handedness and finish off with a sprinkling of powdered dragon's horn to get what a group of researchers are calling the "perfect invisible cloak."

Teams at St Andrews University in Soctland and Toyama Prefectural University in Japan have combined to produce some seriously theoretical material that - if it were actually possible to make - might indeed appear like witchcraft.

No shimmer, no see

The 'left-handed' metamaterial they theorise about doesn't exist yet, but if they did it would "generate no reflection or phase delay at all even when an electromagnetic wave passes through it".

In other words, even light would pass straight through without so much as a Predator-like shimmer to give away the resulting invisibility effect.

Naturally, the researchers are drawing attention to their intriguing work by talking, in layman's terms, about an invisibility cloak, but we prefer the notion of something a lot bigger. Perhaps a giant wrapper to hide the Earth from that marauding alien fleet that's bound to turn up one day?