Friday, 9 October 2026
AI proof verification fails the Navier-Stokes test; battery storage undercuts gas turbines worldwide; C's undefined behavior gets cut
Today's Lead
EngineeringarXiv
Navier-Stokes lost in translation: Why Lean verification of AI autoformalisation does not guarantee correct natural language proofs
The paper studies autoformalisation, which translates mathematical text into the Lean proof language. The authors argue that a successful Lean check does not prove the original natural language proof is correct. Faithful translation needs ambiguity resolution, which the authors classify as harder than any computational problem, including the Halting problem. The example is OpenAI's announced Navier-Stokes proof, whose Lean version does not match the natural language argument.
Engineering
Cactus Compute
Whistle: Speech to Text in 16.9 MB
Cactus Compute released Whistle, an open speech-to-text model in a single 16.9 megabyte (MB) file. The model uses a convolutional front end, an encoder that reads the full clip, and a decoder with cross-attention. Whistle is smaller than Whisper base (145.3 MB) and Moonshine tiny v2 (41.9 MB). It runs on the CPU without dependencies, and audio stays on the device after the first model download.
Solar Power World
4-hour battery storage is cheaper to install than gas turbines all across globe
Wood Mackenzie reports that four-hour battery storage is now cheaper than open-cycle gas turbines in all 43 modeled markets. Battery costs fall as manufacturing expands, while gas turbine shortages and fuel price changes raise peaking costs. The economic case for new gas peaking plants becomes weaker, and storage is key for renewable power.
LWN
Reducing undefined behavior in the C language
Martin Uecker, speaking at Kernel Recipes 2026 and reported by LWN, argues that C's undefined behavior (UB) lets compilers do anything, which causes inconsistent results and blocks memory safety. The C committee is cutting UB: about 100 instances remain, and the C2y draft removes 45 of them, while C23 already dropped sign-magnitude and one's-complement support. Uecker splits memory safety into type safety (mostly solvable), spatial safety (partly solved, with bounds checks and counted_by), and temporal safety (hardest, needing hardware such as CHERI or formal verification). The push is urgent because C remains widely used, and demand for memory safety keeps growing.
Let's Encrypt
64-Day Certificate Lifetimes Coming Feb 2027
Let's Encrypt reduces the default certificate lifetime from 90 days to 64 days. This change reduces the risk of key compromise and mis-issuance. On February 10, 2027, all new and renewed certificates use the 64-day lifetime by default. Operators must confirm that their clients renew at about two-thirds of the lifetime, or use ACME Renewal Information (ARI).
Humanities
Aeon
Barbara Ward's vision
Barbara Ward, a British economist and journalist (1914–1981), argued that development, equality and environmental protection were linked problems that needed planetary solutions. Her 1965 "Spaceship Earth" lectures and the 1972 Stockholm report "Only One Earth" framed Earth as a fragile shared home, and she called for a 1% tax on national income for aid. She saw growth as necessary but limited by ecology, and warned that "our physical unity has gone far ahead of our moral unity." Historian Or Rosenboim argues her vision still fits today's inequality, environmental and global governance problems, provided it is separated from her paternalistic assumptions.
JSTOR Daily
Why King Arthur Still Shapes Pop Culture
The legend of King Arthur endures because filmmakers, musicians, and advertisers keep adapting it. In modern media, Arthur stands for order, justice, and safety — a function that lets any group project its values onto the myth. Some works use Arthur ironically to question that order; others appropriate it for darker ends, including far-right movements and, per the article, ISIS. Scholars Ferszt and Bump conclude that the Arthurian legend is a receptive vessel waiting to be filled by the aspirations and anxieties of whoever chooses to claim it.