1Quantum computers do not simply calculate faster than the ordinary machines we all use at home.
2They follow the strange rules of physics that govern the smallest particles in the universe.
3While a normal bit is either on or off, a quantum bit can be both at exactly the same time.
4This remarkable property allows the machine to explore millions of possible answers in a single moment.
5Pharmaceutical companies hope these machines will help them design new medicines within weeks instead of years.
6Banks are already testing quantum models that predict how global markets will behave under pressure.
7And yet the technology remains extremely fragile and astonishingly expensive to build and operate today.
8The machines must be kept colder than the emptiest regions of outer space to work correctly.
9Even a single vibration from a passing lorry outside the building can ruin an entire calculation.
10Some optimistic researchers predict that practical machines will finally arrive within the next decade or two.
11Others warn that the same grand promises have been repeated for more than thirty years already.
12Either way, governments around the world are investing billions of dollars to avoid being left behind.