The Download: DeepSeek's latest AI breakthrough, and the race to build world models Plus: China has blocked Meta's $2 billion acquisition of AI startup Manus. On Friday, Chinese AI firm DeepSeek released a preview of V4, its long-awaited new flagship model. Notably, the model can process much longer prompts than its last generation, thanks to a new design that handles large amounts of text more efficiently. While the model remains open source, its performance matches leading closed-source rivals from Anthropic, OpenAI, and Google. Here are three ways V4 could shake up AI . AI systems have already gained impressive mastery over the digital world, but the physical world remains humanity's domain.

The Download: Kenya's Great Carbon Valley, and the AI terms that were everywhere in 2025 Welcome to Kenya's Great Carbon Valley: a bold new gamble to fight climate change In June last year, startup Octavia Carbon began running a high-stakes test in the small town of Gilgil in south-central Kenya. It's harnessing some of the excess energy generated by vast clouds of steam under the Earth's surface to power prototypes of a machine that promises to remove carbon dioxide from the air in a manner that the company says is efficient, affordable, and--crucially--scalable. The company's long-term vision is undoubtedly ambitious--it wants to prove that direct air capture (DAC), as the process is known, can be a powerful tool to help the world keep temperatures from rising to ever more dangerous levels. But DAC is also a controversial technology, unproven at scale and wildly expensive to operate. On top of that, Kenya's Maasai people have plenty of reasons to distrust energy companies. This article is also part of the Big Story series: 's most important, ambitious reporting.