Two female students have made history at the 2022 Big Bang UK Young Scientists and Engineers Competition, after they won the top two awards. It’s the first time both top prizes have been won by girls. The two winners were Connie Gray and Avye Couloute, who are both 14 years old.

Gray won the UK’s Young Scientist award for her research comparing the structures of birds’ feathers from different environments and climates. Her aim was to help with conservation efforts in areas around the world that are most affected by climate change. Couloute won the UK’s Young Engineer award for inventing a device to measure the levels of carbon dioxide (CO₂) in a building, in an attempt to improve air quality. Reducing CO₂ levels could benefit classrooms and offices. Both winners received prizes of 2,000 pounds to continue their journeys in science, technology, engineering, and maths (STEM).

The competition was hosted at the Big Bang Fair in Birmingham, which ran from 22 to 24 June, and is a free celebration of STEM for 11 to 14-year-olds. More than 40, 000 young people enjoyed activities such as slime-making, drone-flying and using virtual reality (VR) to look at how the oceans can be saved. The organizers aimed to inspire young people to consider careers in STEM.

A survey was carried out before the event to find out how many young people are interested in STEM subjects and careers. It found that 40% of 11 to 16-year-olds said a career in STEM would allow them to make positive change in the world.

Dr Hilary Leevers, who was involved in organizing the fair, said, “It’s really encouraging that people are embracing STEM at an early age. We need more young people from all backgrounds to understand the role that STEM careers play, and for more of them to go on to work in science, engineering and technology.”

When customers in downtown Vancouver placed orders with Pizza Hut in September, many of the pies landed on their doorsteps without a person in sight. Instead, diners were met by autonomous robots looking like a cooler on four wheels with eyelike lights.

The belief held by Serve Robotics is simple: with slim restaurant profits, a labor shortage and climate change worries “Why move a two-pound hamburger in a two-ton car?” A handful of other robotic delivery companies have the same idea, but they are facing several roadblocks.

“They’re drawing a lot of attention from people while they’re out on the sidewalk because they’re not seeing them that often and people are excited to see them, but as usage continues to increase, this can cause a lot of crowding on already narrow sidewalks,” said Prabhjot Gill, a McKinsey & Co. associate partner.

Ali Kashani, Serve’s Vancouver-bred chief executive, considers the criticism to be a natural part of innovation and thinks they are “a win-win for everybody“. But he’s tried to quiet concerns by ensuring his robots flash their lights to warn people they are around. They are equipped with automatic crash prevention, vehicle collision avoidance and emergency braking.

However, David Lepofsky, chair of the Accessibility for Ontarians with Disabilities Act Alliance, said, ”It’s not like we’re denying people a service. We’ve got a way to deliver pizzas that we’ve had since we’ve had pizza delivery. It’s called human beings.“

Manish Dhankher, Pizza Hut Canada’s chief customer officer, agrees no pizza delivery is worth risking somebody’s safety, but said his company only partnered with Serve once the robots had made thousands of injury-free trips.

Serve robots only made nearby deliveries for Pizza Hut’s 1725 Robson St. location for two weeks, but the pilot generated ”childlike excitement“ from customers and had a 95 per cent satisfaction rate.

But Pizza Hut isn’t ready to roll out robots permanently.

”We want to learn more,“ he said. “What happens when you put this in the snowy areas of Saskatchewan and what happens when there is freezing rain?”

Strategically adding weak points along microscopic chains called polymers (高分子聚合物) actually makes them harder to tear, researchers report in the June 23 Science. Polymers are used in car tires, and therefore the findings could help reduce plastic pollution as tires wear down over time.

When tires rub against the road, they drop microplastics of rubber and plastic polymers, which pollute waterways and air. Every year, tires release an estimated 6 million metric tons of these microplastics into environment. Stronger polymers that break apart less easily could limit the amount of particles shed annually.

To make such tough materials, Stephen Craig, a chemist at Duke University, and colleagues added molecules called cross-linkers to the polymers. These cross-linkers connected these polymer chains to their many neighbors, and they were specifically designed to break apart easily. At the microscopic scale, the polymers act like a tangle (乱团) of spaghetti with the cross-linkers holding them all together and helping them keep their shape, says Craig’s collaborator Shu Wang, a chemist at MIT. When the team stretched the polymer spaghetti, the individual cross-linkers broke easily, as expected. But the larger tangle material required more force to break than they expected.

The secret to the increased toughness lies in the path the tear has to take, Craig says. The tear goes through the easy-to-break cross-linkers rather than through the tougher polymer chains. Each broken connection follows the path of least resistance but avoiding the long polymer chains means breaking many cross-linkers, which requires more stretching force overall.

This isn’t the first time researchers have used weak connectors to make polymers stronger. But unlike in similar materials, the increased toughness doesn’t come at the expense of other beneficial properties like stiffness (风度). Craig says he hopes the findings will help extend the lifetimes of car tires and plastics, potentially limiting annual microplastic pollution.