Beneath gilded portraits and suits of armour in Windsor Castle, 160 guests wined and dined at a lavish banquet to fete US President Donald Trump's unprecedented second state visit to the UK on Wednesday evening. Along with the impeccable table settings, three-course meal and custom cocktail, who was there and, just as importantly, who was seated next to who is carefully planned, since the event is as much about diplomacy as it is about fine dining. This year's guest list was conspicuously missing screen stars or celebrity faces, with not even royal perennials like Sir David Beckham or Sir Elton John attending. Instead, the list was mostly royals, tech and finance executives, and politicos from both sides of the Atlantic. From Trump's seat of honour at the centre of the table, next to his host King Charles III, those up and down the table ranged from lesser-known but influential White House players to professional golfers.

This week, UK prime minister Rishi Sunak is hosting a group of 100 representatives from the worlds of business and politics to discuss the potential and pitfalls of artificial intelligence. The AI Safety Summit, held at Bletchley Park, UK, begins on 1 November and aims to come up with a set of global principles with which to develop and deploy "frontier AI models" – the terminology favoured by Sunak and key figures in the AI industry for powerful models that don't yet exist, but may be built very soon. While the Bletchley Park event is the focal point, there is a wider week of fringe events being held in the UK, alongside a raft of UK government announcements on AI. Here are the latest developments. The summit got off to a bang with the announcement that 28 countries have agreed a declaration saying global action is needed to tamp down the risks of AI.

They diagnose illnesses, help you find photos of your cat, decide whether to give you a loan1. They make up a huge part of what we call "machine learning" or "artificial intelligence," especially the new, exciting, scary parts of it. And, given the magnitude of the problems they can handle, they're simpler than you'd expect. Most explanations of neural networks for lay people are kind of lousy, because they always start by talking about brains. They'll define neural networks as "computer systems modeled on the human brain" or "programs that learn the same way as people" or even as "artificial brains."