Quantum computing: how the world's coolest computers (literally) could solve some of the biggest problems

Let’s get one thing out of the way: a quantum computer is not going to replace your current laptop, help you win at Wordle, or untangle that drawer of cables you keep meaning to sort out. Some things are beyond even quantum physics, and that cable drawer is probably one of them. But these incredibly advanced, super-chilled machines could help solve some of humanity’s biggest headaches, and the tech giants are pouring serious money into making that happen.

This isn’t just wishful thinking from a few boffins in lab coats, though. IBM, Google, Microsoft and Amazon are all investing heavily in quantum tech, alongside a crowd of ambitious start-ups. In an IBM explainer, McKinsey’s estimates are quoted, suggesting that the quantum computing industry could be worth a whopping $1.3 trillion by 2035. That’s a lot of cash for something most of us couldn’t explain down the pub. But here we will give it a go so you might be one of the few who can, and then explain why it all matters.

What actually is quantum computing?

Your phone, your PC, and that smart fridge you probably never use all think in bits: tiny switches that are either off (0) or on (1). Simple, reliable, and, compared to quantum computers, rather boring. Quantum computers, meanwhile, use qubits instead. As Microsoft explains, a qubit can hold a mix of possibilities at once rather than committing to a single value. Think of flipping a coin: a normal bit is either heads or tails, with the answer one or the other, while a qubit is the coin still spinning in mid-air, with the answer determined only when you look.