We already reported that Willow completed a computation in under five minutes that would supposedly take the world’s fastest supercomputer ten septillion years. Still, according to Google Quantum AI founder Hartmut Neven, “This mind-boggling number exceeds known timescales in physics and vastly exceeds the age of the universe.”
He even invoked the multiverse hypothesis, positing that quantum computation may use many parallel universes—a nod to David Deutsch’s 1997 book, The Fabric of Reality.
Let’s not get carried away by thoughts of multiverse-hopping quantum chips just yet. As German physicist Sabine Hossenfelder put it: “The result of this calculation has no practical use. Google chose this problem because it’s challenging for classical computers, allowing them to flaunt their chip’s apparent superiority. “
If this sounds familiar, it’s because Google made similar headlines in 2019 with a 50-qubit chip, claiming “quantum supremacy.” However, IBM researchers later deflated their achievement, finding that a classical computer could perform the same task in just 2.5 days.
Willow’s 100-qubit architecture doubles down on quantum weirdness, using qubits in a superposition of states. Yet, even Google’s critics note that practical quantum computing applications remain away for years—if not decades.
Hossenfelder said: “We will need about 1 million qubits for practically useful applications, and we're still about 1 million qubits away from that.”
And then there’s the lingering spectre of debunking. Google’s 2019 quantum supremacy claim sparked a feud with IBM, which accused the company of overstating its achievement. There’s every chance Willow’s multiverse-powered performance will meet a similar fate as researchers refine classical approaches to solve these “unsolvable” problems.
Neven, for his part, is optimistic about the future: “This is the most convincing prototype for a scalable logical qubit built to date. It’s a strong sign that huge, useful quantum computers can be built.”
As a scientific achievement, Willow is undeniably impressive. But it's far less compelling as a practical tool—or proof of parallel universes. While Google’s engineers deserve credit for pushing the boundaries of what quantum computers can do, the grandiose claims about multiverse computation feel more like an attempt to keep Google at the centre of the quantum hype machine.
