Dion optimizer | Claude safeguards | Lunar dust bricks | Perplexity’s Chrome bid

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Dion: the distributed orthonormal update revolution is here
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• Dion is a new optimizer designed to make training large AI models more efficient by orthonormalizing only the top singular vector subspace, reducing communication and compute overhead while maintaining performance.

• It leverages amortized power iteration plus QR decomposition to approximate orthonormal updates without full-scale matrix operations and is fully compatible with distributed training techniques like FSDP and tensor parallelism.

• At large scales (e.g., LLaMA-3 at 405B parameters), using low-rank Dion (as little as 1/16 rank) offers massive wall-clock time speedups over Muon, and the code is open-source with a PyTorch implementation available.

Building Safeguards for Claude
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• Anthropic’s Safeguards team develops multi-layered protections across the model lifecycle—including policy setting, adversarial testing, and real-time enforcement—to ensure Claude remains both helpful and safe.

• They employ a “Unified Harm Framework” to assess potential misuse across physical, psychological, economic, societal, and autonomy dimensions, and iterate policies using expert-driven stress tests (e.g., during the 2024 U.S. election).

• Post-deployment, real-time classifiers detect harmful outputs, enabling tactics like response steering or account enforcement; ongoing monitoring aggregates behavior over time, and efforts include a bug bounty and partnerships for system improvements.

'Building cities on the Moon': Chinese scientists develop machine to turn lunar dust into bricks
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• Researchers from China’s Deep Space Exploration Laboratory in Hefei built a solar-powered 3D-printing device that uses concentrated sunlight—via parabolic reflectors and fiber optics—to melt lunar soil at over 1,300 °C and produce dense, durable bricks solely from regolith.

• While these bricks alone can’t hold pressure in the Moon’s environment, they are envisioned as protective outer layers for pressurized rigid or inflatable habitat modules, offering radiation and micrometeorite shielding.

• The project, spanning two years, tackled challenges like variable soil composition using simulants, and prototypes (including brick samples) were sent via Tianzhou-8 in November 2024 to the Tiangong station for exposure testing in space conditions.

Perplexity offers to buy Google Chrome for $34.5 billion
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• AI search startup Perplexity reportedly extended an unsolicited bid of $34.5 billion to acquire Google Chrome—significantly above Chrome’s own valuation and higher than Perplexity’s estimated worth (~$18 billion).

• This follows a prior statement by Perplexity that it would purchase Chrome if regulators compelled Google to divest—though no such divestment has been mandated.

• Perplexity confirmed media reports, and plans to invest over $3 billion into Chrome and Chromium over the next two years, backed by large investment funds; Google has not responded or expressed intent to sell.