In the world of high-performance computing, we are used to big numbers. We talk about exaFLOPS, zettabytes, and billions of transistors. We track the Top500 list like a sports league, celebrating when a new supercomputer squeezes out a few more percentage points of performance.
But every once in a while, a breakthrough arrives that doesn’t just move the needle; it breaks the scale entirely.
In a recent announcement, Google Quantum AI unveiled Willow, a new quantum computing chip that completed a benchmark calculation in under five minutes. According to Google, a brute-force classical simulation of the same task would take the world’s fastest supercomputers roughly 10 septillion years (1025).
For perspective, the universe itself is only about 13.8 billion years old.
Willow is more than a speed record. It represents a turning point where quantum computing shifts from experimental curiosity to a system that fundamentally outperforms classical physics for specific problems. Even more provocatively, Google’s leadership suggests it may offer indirect evidence for one of the strangest ideas in modern physics: the multiverse.
What is Google Willow?
Willow is Google’s latest-generation quantum processor, following the earlier Sycamore chip that first demonstrated quantum advantage in 2019. Built using superconducting transmon qubits, Willow contains 105 qubits arranged in a tightly coupled grid optimized for error correction and quantum interference.
While the raw qubit count matters, Willow’s real significance lies elsewhere: it crossed a threshold that physicists and engineers have been chasing for decades.
The real breakthrough: “Below Threshold” error correction
Quantum computers have always suffered from a fatal flaw: noise.
Qubits are extraordinarily fragile. Heat, stray electromagnetic fields, or even cosmic rays can cause them to lose their quantum state, a process known as decoherence. Historically, adding more qubits made things worse, not better. Larger systems collapsed under their own errors.
Willow changes that. With this processor, Google demonstrated below-threshold error correction, meaning that as more qubits were added, the overall error rate dropped exponentially instead of rising.
Think of this as the Wright Brothers moment for quantum computing. Before Willow, adding more qubits was like adding weight to an aircraft that could not yet fly. Willow proves that larger quantum machines can actually become more stable as they scale.
In practical terms, this is the prerequisite for building future systems with millions of logical qubits, not just hundreds of fragile physical ones. Without this breakthrough, useful quantum computing would remain impossible.
The 5-minute vs. 10-septillion-year experiment
Google tested Willow using a benchmark called Random Circuit Sampling (RCS).
What is Random Circuit Sampling?
RCS involves tracking the probability distribution of outputs from a randomly generated quantum circuit. It is intentionally designed to be:
- Natural for quantum systems
- Catastrophically inefficient for classical simulation
The results of the experiment
- Willow: Completed the task in under 5 minutes
- Classical Supercomputers: Estimated 10 septillion years using brute-force simulation, even under idealized assumptions
This comparison is not about everyday workloads like web browsing or AI inference. It demonstrates that there are computational regimes where classical machines, no matter how large, simply cannot keep up.
Willow vs. the world’s fastest supercomputers
This announcement comes during the Exascale Era of classical computing.
The current performance leader is El Capitan, housed at Lawrence Livermore National Laboratory, capable of roughly 1.74 exaFLOPS. Europe has answered with Alice Recoque, France’s flagship exascale system designed to support scientific sovereignty.
These machines are engineering marvels. They excel at:
- Climate modeling
- Nuclear simulations
- Large-scale AI training
But they rely on classical bits, 0s and 1s, operating linearly. Quantum processors like Willow operate in an entirely different computational space.
Rather than replacing supercomputers, Willow establishes a new category: quantum-native problems that classical hardware cannot feasibly solve at all.
A necessary clarification on the multiverse
Before going further, an important distinction must be made. Google has not proven the existence of parallel universes.
Willow’s results are an engineering and physics milestone regardless of how quantum mechanics is interpreted. The multiverse enters the story through interpretation, not measurement.
The Multiverse theory: Why Google is even talking about it
Hartmut Neven, founder of Google Quantum AI, stated that Willow’s performance “lends credence to the notion that quantum computation occurs in many parallel universes.”
This idea comes from the Many-Worlds Interpretation (MWI) of quantum mechanics, first proposed by Hugh Everett and later championed by physicist David Deutsch.
The Core Idea
- Classical computers compute sequentially
- Quantum computers operate using superposition and interference
- Many-Worlds Interpretation: Each quantum outcome exists in a branching reality
Under this framework, a quantum computer does not perform impossible amounts of work in one universe. Instead, the computation is effectively distributed across countless parallel branches, which then interfere to produce a final result.
Neven’s argument is philosophical rather than experimental: if a computation appears to exceed the resources of a single universe, perhaps those resources are not confined to one.
Why are many physicists skeptical?
Despite the attention-grabbing headlines, the multiverse explanation remains a subject of controversy.
Critics argue:
- The mathematics of quantum mechanics does not require physically real parallel universes
- Other interpretations (such as Copenhagen) explain the same results without metaphysical commitments
- “Shut up and calculate” remains the dominant attitude in applied physics
In short, Willow does not force belief in the multiverse; it merely keeps the debate alive.
The hybrid future: Willow, Ironwood, and Helios
Google is not betting exclusively on quantum computing. The future is hybrid.
While Willow explores problems beyond classical reach, Google’s Ironwood TPU powers today’s AI inference at a planetary scale. At the same time, competitors like Quantinuum Helios are pursuing trapped-ion quantum systems with higher per-qubit fidelity and tight integration with classical AI accelerators.
The winning architectures of the next decade will combine:
- CPUs
- GPUs
- TPUs
- QPUs (quantum processors)
Each will handle the tasks for which they are uniquely suited.
Conclusion: The first glimpse beyond classical limits
Google Willow is still a research prototype. The task solved has no immediate commercial use. But history shows that foundational breakthroughs rarely do.
What Willow proves is profound:
- Scalable quantum error correction is real
- Quantum advantage is now experimentally undeniable
Whether or not quantum computers truly tap into parallel universes, one thing is certain: the boundaries of computation have expanded beyond what classical physics alone can explain. This was proven by the University of Stuttgart: they managed to achieve quantum teleportation between two distant light sources!
The five-minute universe has arrived.
