How to make things invisible
The prospect of being invisible has long been a staple of science fiction and fantasy, from Harry Potter's invisibility cloak to the spaceships of TV shows and films like Star Trek.
The problem is that the laws of physics mean any solution relies on hiding things in wavelengths longer than the human eye can see - or hiding objects so small we can't see them.
Nevertheless, scientists around the world are working on methods to cloak objects from sight.
Professor Chris Phillips from Imperial College London spoke to BBC News about some of the work being done on making invisibility a reality.
- From the section Science & Environment