Some seemingly simple sequences of multiplication and addition grow so quickly that they question the very foundations of mathematics. Did you hear the one about the man who invented chess and got himself executed? Legend has it that a man called Sessa, who lived in India long ago, developed the rules for the game and presented them to a king. The king was delighted and offered the man his pick of reward. Sessa asked for a supposedly humble quantity of rice.

Standard decoding strategies for text generation, including top-k, nucleus sampling, and contrastive search, select tokens based on likelihood, restricting selection to high-probability regions. Human language production operates differently: tokens are chosen for communicative appropriateness rather than statistical frequency. This mismatch creates a truncation blind spot: contextually appropriate but statistically rare tokens remain accessible to humans yet unreachable by likelihood-based decoding. We hypothesize this contributes to the detectability of machine-generated text. Analyzing over 1.8 million texts across eight language models, five decoding strategies, and 53 hyperparameter configurations, we find that 8-18% of human-selected tokens fall outside typical truncation boundaries. Simple classifiers trained on predictability and lexical diversity achieve remarkable detection rates. Crucially, neither model scale nor architecture correlates strongly with detectability; truncation parameters account for most variance. Configurations achieving low detectability often produce incoherent text, indicating that evading detection and producing natural text are distinct objectives. These findings suggest detectability is enhanced by likelihood-based token selection, not merely a matter of model capability.

Academics discover black people'significantly more likely' to be identified when compared with other ethnic groups Essex police have paused the use of live facial recognition (LFR) technology after a study found cameras were significantly more likely to target black people than people of other ethnicities. The move to suspend use of the AI-enabled systems was revealed by the Information Commissioner's Office (ICO), which regulates the use of the technology deployed so far by at least 13 police forces in London, south and north Wales, Leicestershire, Northamptonshire, Hampshire, Bedfordshire, Suffolk, Greater Manchester, West Yorkshire, Surrey and Sussex. The ICO said Essex police had paused LFR deployments "after identifying potential accuracy and bias risks" and warned other forces to have mitigations in place. LFR systems are either mounted to fixed locations or deployed in vans. In January, the home secretary, Shabana Mahmood, announced the number of LFR vans would increase five-fold, with 50 available to every police force in England and Wales. Essex commissioned University of Cambridge academics to conduct a study, which involved 188 actors walking past cameras being actively deployed from marked police vans in Chelmsford.

'British FBI' to take over terror and fraud probes in reforms to police A new national police force is being created to take over counter-terror, fraud, and criminal gang investigations. Home Secretary Shabana Mahmood said the new National Police Service (NPS), described as a British FBI, would deploy world class talent and state of the art technology to track down and catch dangerous criminals. It will bring the work of existing agencies such as the National Crime Agency and regional organised crime units under the same organisation, buying new technology such as facial recognition on behalf of all forces. Mahmood said policing was stuck in a different century and the new body will form part of a series of police reforms she will unveil on Monday. The NPS will cover England and Wales but be able to operate in the wider UK, setting standards and training.

A BBC investigation has uncovered claims that essay cheating remains widespread at UK universities despite the introduction of a law designed to stop it. Since April 2022, it has been illegal to provide essays for students in post-16 education in England. But so far there have been no prosecutions. The BBC has spoken to a former lecturer who describes essay cheating as an open secret and to a businessman who claims to have made millions from selling model answer essays to university students. Universities UK, which represents 141 institutions, said there were severe penalties for students caught submitting work that was not their own.

Kevin Sinfield has completed seven ultramarathons in seven days to raise money and awareness for motor neurone disease (MND). The rugby league legend ran about 300km (185 miles) throughout the week, starting at Bury St Edmunds Rugby Club and ending at Leeds Rhinos home ground, Headingley Stadium. The 45-year-old completed an ultramarathon of at least 45km (27.9 miles) each day of his challenge, in bursts of 7km (4.3 miles). On Sunday he crossed the finish line in front of hundreds of supporters, who had gathered in the stadium's North and West stands to cheer him on. He said: To the MND Community and the people we've met on route, all through the last week, all through the past five years, to everybody we've met - it's an absolutely beautiful community.

How conspiracy theories infiltrated the doctor's office Every day, physicians and therapists work to keep their patients safe. As anyone who has googled their symptoms and convinced themselves that they've got a brain tumor will attest, the internet makes it very easy to self-(mis)diagnose your health problems. And although social media and other digital forums can be a lifeline for some people looking for a diagnosis or community, when that information is wrong, it can put their well-being and even lives in danger. Unfortunately, this modern impulse to "do your own research" became even more pronounced during the coronavirus pandemic. We asked a number of health-care professionals about how this shifting landscape is changing their profession. They told us that they are being forced to adapt how they treat patients.