The case against Google's claims of "quantum supremacy"

Context: Google’s “Supremacy” and Willow Claims

• The blog post revisits Google’s 2019 random circuit sampling “quantum supremacy” result in light of the new Willow chip and a dramatic “septillion years” classical runtime claim.
• Some see nothing fundamentally new: same benchmark, slightly larger circuits (53→67 qubits), and argue we could be repeating this cycle with larger devices in future years.

Verification, Benchmarks, and Hype

• Core concern: random circuit sampling isn’t practically important and is hard to verify independently, since the whole point is to exceed classical simulation.
• Earlier “billions of years” estimates were later challenged by better classical algorithms, suggesting the original gap was overstated.
• Several commenters argue Google’s communication style is overly hyped compared to the underlying incremental technical progress.

Shor’s Algorithm and Actual Capability

• Multiple comments note that genuine implementations of Shor’s algorithm haven’t gone beyond trivial numbers (15, 21), and even those used heavily simplified, “cheating” circuits.
• This is contrasted with public perception that widespread cryptographic breakage is imminent.

Quantum Error Correction and Scalability

• The blog author in-thread emphasizes statistical anomalies in Google’s 2019 fidelity modeling (too-perfect fit), not the existence of exponential decay per se.
• Others counter that multiple independent experiments show the expected exponential fidelity falloff consistent with simple noise models, and view the critique as increasingly out of touch.
• There is active disagreement over whether quantum error correction will scale or fundamentally break down.

Security, Intelligence Agencies, and Post‑Quantum Planning

• Debate over whether intelligence agencies might already have secret, more powerful quantum machines; many doubt they could be dramatically ahead of large companies.
• Some stress “store now, decrypt later” risks and blackmail value of old secrets; others argue the storage and collection costs at global scale are enormous.
• On migration: centralized banks are seen as more able to coordinate a post‑quantum transition than decentralized cryptocurrencies, which face governance and overhead challenges.

Applications and Value Proposition

• Mentioned potential uses: chemistry and materials simulation, optimization (e.g., logistics, rail networks), quantum networking (superdense coding, quantum key distribution).
• Several commenters note many current industrial “use cases” look like PR toy problems rather than real business advantages.
• A minority dismiss quantum computing as “vaporware,” while others argue progress is slow but real, comparable to long-running efforts like nuclear fusion.

Skepticism, Optimism, and the Role of Critics

• Thread repeatedly returns to the value of informed skeptics: they may be wrong long‑term but help refine methods and temper overclaims.
• Others warn against both nitpicky contrarianism and uncritical hype, emphasizing that extraordinary claims require robust, reproducible evidence.