There is a computer capable of doing, in seconds, calculations that would take the world’s best computers thousands of years. It is not a science-fiction promise: it already exists, it works, and some of the most important laboratories on the planet are competing to make it ever more powerful. We are talking about quantum computing.
From the bit to the qubit: the leap of an idea
To understand it, it is worth forgetting everything we know about current computers. They work with bits, which are like switches that can only be in two positions: on (1) or off (0). With millions of these switches, the machine does its calculations in sequence.
Quantum computers use something similar but much stranger: qubits. The difference is that a qubit can be in both positions at the same time. It is as if a coin spinning in the air were neither heads nor tails, but a mixture of the two. That, called superposition, makes it possible to explore a huge number of possibilities at once instead of one after another.
It is not a magic machine
It is worth clarifying a nuance: we are not going to replace the home computer with a quantum one. For writing an email, watching a series or using social networks, current computers are perfect. Quantum ones are tools for very specific and very difficult problems, those in which the list of possibilities grows so fast that no classical machine can cope with it.
What would it really be useful for?
The most talked-about uses sound like something out of a movie. In medicine, for example, they could simulate molecules with precision to design new drugs much faster. In chemistry, they would help create stronger materials, better batteries or less polluting fertilisers.
They also promise to revolutionise logistics: calculating the best route for thousands of trucks, planes or ships at the same time, saving fuel and time. And in finance, finding patterns in mountains of data that are impossible to process today.
All of this is still in its early stages. Current quantum computers make mistakes easily and are difficult to manage, but every year they become more stable. It is like watching an aeroplane on its first flights: the idea already flies, it just needs to be made reliable.
The race for the future
Governments and large companies are investing enormous sums in this technology. And no wonder: whoever achieves a powerful, stable quantum computer will have a huge advantage in almost every sector. That is why many call it the new space race, but in laboratory version.
For now, the most fascinating thing is that this story has just begun. Quantum computing is not going to replace the computers we know, but rather to solve the problems those computers could never touch. And watching it advance, step by step, is one of the most exciting stories in today’s technology.
