Science Stories

A World Cup stadium holds tens of thousands of people moving through security checkpoints, food courts, and different sections. For organisers, monitoring these crowds is essential for preventing dangerous situations. But do crowd monitoring systems protect people’s privacy? “Privacy is a human right. Privacy protection must be built into the design of the system,” Fatemeh Marzani, a PhD candidate in Computer Science at the University of Twente, says.

Yellow grass. Low river levels. Nature reserves drying out. While people in the Netherlands are used to talking about flooding and excess water, we are increasingly facing the opposite problem: drought. At the University of Twente, researchers are working on an urgent question: how can we help the Netherlands, and regions around the world, better cope with drought and water scarcity?

A ball that suddenly changes direction. An opponent applying pressure. A teammate making a run into space. Footballers constantly make decisions in fractions of a second. For humans, it feels almost effortless. For robots, it is one of the most difficult challenges imaginable.

The 2026 World Cup album has 980 spaces. A packet holds seven stickers. So 140 packets should do the job. Then you are fifty packets in, the album is half empty, and you keep opening players you already have. Why does a 980-sticker album swallow so many packets? We put it to UT mathematician Clara Stegehuis, who studies how randomness behaves in large networks.

Anyone watching the World Cup will see it happen in every match. Around the 23rd minute, the referee stops play, and the players reach for their water bottles. Twice per match, even late at night and even in an air-conditioned stadium. Why is that necessary? The answer says less about football than about how heavily heat strains the body.