In Lulea, a city in northern Sweden, the sun only shines around three hours a day in the winter months. People tend to stay warm at home and that can be very lonely. To help ease winter loneliness, the local authority is asking everyone to just say hello to each other. The new campaign is called Sag hej.

While the world is experiencing an increase in loneliness following the Covid-19 pandemic, in places that do not get a lot of sunlight during the winter months, the issues are exasperating.

“Loneliness and isolation are major problems at any time of the year and almost everywhere in the world right now,” Micael Dahlen, professor of wellbeing and happiness at the Stockholm School of Economics, said. “It comes with the times that we live in, with the lifestyles that we have, where we don’t necessarily encounter each other to the same extent that we used to. This increases in winter when we are outside less and socializing less,” he added.

While most people believe that loneliness is most common amongst seniors who tend to live alone, the opposite is true. It is actually rising in young people. A recent study published in the International Journal of Adolescence and Youth found that loneliness in young people has been increasing and this negatively impacts mental and physical wellbeing. Research about Lulea found that 45 percent of 16-to-29-year-olds were experiencing problems due to being lonely.

Asa Koski, who works for the city, came up with the idea of the Sag hej! campaign. She wants the city, which is undergoing rapid growth due to green industry jobs, to be a friendlier, more welcoming, and less lonely place for newcomers. “We don ’t just want that Lulea is going to grow as a city; we want Lulea to be a pleasant and safe and friendly city as well where there’s culture, leisure activities, and sport,” said Koski.

Many people agree that saying hello should be encouraged and believe that the more international the city becomes, the more people will become friendlier too.

Three scientists jointly won this year’s Nobel Prize in physics for proving that tiny particles (粒子) could keep a connection with each other even when separated, a phenomenon once doubted but now being explored for potential real-world applications such as encoding information. Frenchman Alain Aspect, American John F. Clauser and Austrian Anton Zeilinger were quoted by the Royal Swedish Academy of Sciences for experiments proving the “totally crazy” field of quantum entanglements (量子纠缠) to be all too real. They demonstrated that unseen particles, such as photons (光子) , can be linked, or “entangled”, with each other even when they are separated by large distances.

In quantum entanglement, establishing common information between two photons not near each other “allows us to do things like secret communication, in ways which weren’t possible to do before”, said David Haviland, chair of the Nobel Committee for Physics. Quantum information “has broad and potential effects in areas such as secure information transmission, quantum computing and sensing technology”. The kind of secure communication used by China’s Micius satellite, as well as by some banks, is a “success story of quantum entanglement”, said Harun Siljak of Trinity College Dublin.

The Nobel Committee said Clauser developed quantum theories first put forward in the 1960s into a practical experiment. Aspect was able to correct an error in those theories, while Zeilinger demonstrated a phenomenon called quantum teleportation that effectively allows information to be sent over distances. “Using entanglement you can send all the information which is carried by an object over to some other place where the object is.” Zeilinger said. He added that this only works for tiny particles. “It is not like in the Star Trek films transporting something, certainly not the person, over some distance,” he said.

Robots have learned to drive on Mars, carry out brain surgery and defeat grandmaster chess players. But when it comes to baking, making tasty desserts is far from a piece of cake. But after multiple failed attempts, US researchers have successfully 3D printed a cherry cheesecake.

The sorry-looking flan resembles a slice of cottage pie, topped with blancmange. Nevertheless, scientists are hopeful that once mastered, 3D printing could replace conventional cooking, allowing food to be tailored to nutritional needs of children, athletes or those on dietary restrictions.

“We have an enormous problem with the low-nutrient value of processed foods,” said Professor Christen Cooper of Pace University Nutrition and Dietetics. “3D food printing will still turn out processed foods, but perhaps the silver lining will be, for some people, better control and tailoring of personalised nutrition. It may also be useful in making food more appealing to those with swallowing disorders by mimicking the shapes of real foods with the mashed texture foods that these patients require.”

In the latest experiment, researchers tried various cheesecake designs, consisting of seven key ingredients: a biscuit base, peanut butter, Nutella, banana puree, strawberry jam, cherry drizzle, and frosting. In early attempts, which involved simply layering up the ingredients, the team found that the cake quickly disintegrated, with jam and peanut butter leaking out onto the work bench.

They discovered through trial and error that a more architectural solution was needed. Walls of biscuit base were required throughout the cake to hold the softer ingredients inside, while internal triangular biscuit supports were necessary to keep the cake upright.

“The study highlights that printed food dishes will likely require novel ingredient compositions and structures, due to the different way by which the food is assembled,” said Cooper. “Much work is still needed to collect data, model, and optimize these processes.”

But the team said that laser cooking and 3D printing could allow chefs to create entirely new food experiences, with flavors and textures placed with millimetre precision. And, because the system uses targeted light for very localized cooking, it could save energy unlike ovens or hobs which heat a large area.