As of: 2026-10-07 23:43 CEST.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code). Human editor: Adam Bicz.
Canonical page: https://postcutoff.com/timeline/2025/09/

# AI in September 2025

12 events: 6 major, 1 historic. Researched afterwards, not logged live, so this count is a floor, not a complete record. Our agents began logging news as it happened on 29 September 2026.
Every event, newest first. Each line: date, short title, page, first primary source.

- 2025-09-30: [OpenAI launches Sora 2 and the Sora social app](https://postcutoff.com/e/2025-09-30-sora-2/). Source: https://openai.com/index/sora-2/
- 2025-09-30: [Periodic Labs launches with a $300M seed round to build AI scientists with autonomous labs](https://postcutoff.com/e/2025-09-30-periodic-labs-300m-seed/). Source: https://www.governor.ny.gov/news/governor-hochul-celebrates-radical-ai-establishing-new-yorks-first-fully-autonomous-materials
- 2025-09-29: [Anthropic releases Claude Sonnet 4.5](https://postcutoff.com/e/2025-09-29-claude-sonnet-4-5/). Source: https://www.anthropic.com/news/claude-sonnet-4-5
- 2025-09-29: [California enacts SB 53, the first US frontier AI transparency law](https://postcutoff.com/e/2025-09-29-california-sb-53/). Source: https://www.gov.ca.gov/2025/09/29/governor-newsom-signs-sb-53-advancing-californias-world-leading-artificial-intelligence-industry/
- 2025-09-27: [Scott Aaronson credits GPT-5 with a key step in a quantum complexity proof](https://postcutoff.com/e/2025-09-27-aaronson-gpt-5-qma-proof/). Source: https://arxiv.org/abs/2509.21131
- 2025-09-22: [NVIDIA and OpenAI announce 10-gigawatt partnership with up to $100B investment](https://postcutoff.com/e/2025-09-22-nvidia-openai-partnership/). Source: https://openai.com/index/openai-nvidia-systems-partnership/
- 2025-09-22: [AlphaEvolve finds gadgets that prove new NP-hardness of approximation bounds for MAX-k-CUT](https://postcutoff.com/e/2025-09-22-alphaevolve-hardness-of-approximation/). Source: https://arxiv.org/abs/2509.18057
- 2025-09-17: [AI reaches gold-medal level at the ICPC World Finals](https://postcutoff.com/e/2025-09-17-icpc-gold-ai/). Source: https://deepmind.google/blog/gemini-achieves-gold-medal-level-at-the-international-collegiate-programming-contest-world-finals/
- 2025-09-17: [DeepMind and mathematicians use neural networks to find new unstable singularities in fluid equations](https://postcutoff.com/e/2025-09-17-deepmind-unstable-singularities-fluids/). Source: https://arxiv.org/abs/2509.14185
- 2025-09-12: [First AI-generated complete genomes](https://postcutoff.com/e/2025-09-12-ai-generated-phage-genomes/). Source: https://www.biorxiv.org/content/10.1101/2025.09.12.675911v1
- 2025-09-10: [Math Inc's Gauss agent completes the Strong Prime Number Theorem formalisation in Lean in three weeks](https://postcutoff.com/e/2025-09-10-math-inc-gauss-strong-pnt/). Source: https://www.math.inc/gauss
- 2025-09-04: [DeepMind's Deep Loop Shaping cuts LIGO control noise 30–100×](https://postcutoff.com/e/2025-09-04-deepmind-ligo-deep-loop-shaping/). Source: https://www.science.org/doi/10.1126/science.adw1291

Older: https://postcutoff.com/timeline/2025/08/
Newer: https://postcutoff.com/timeline/2025/10/