An experiment which saw salad seeds sent into space has given hope for the future of growing food on another planet, according to a recently-published study.

The findings have appeared after two kilograms of seeds spent six months on board the International Space Station(ISS)with British European Space Agency(ESA)astronaut, Tim Peake, as part of his Principia mission.

There, the seeds could have absorbed up to 100 times more radiation(辐射)than on Earth while being influenced by the violent shaking from the stresses of space travel.

When the seeds returned to Earth in 2016,600,000 children from schools across Britain took part in an experiment, supported by the UK Space Agency, to plant them and monitor their growth, comparing it to that of seeds that had remained on Earth.

The results showed that, while the space seeds grew more slowly and were more sensitive to ageing, they were still able to survive.

Peake said, “When humans travel to Mars, they will need to find ways to feed themselves, and this research helps us understand some of the biology of seed storage and germination(发芽) which will be important for future space missions.”

The Royal Horticultural Society(RHS)tasked 8,600 schools and groups across Britain to take part in the controlled study, recording their results as a scientist would.

It was part of a project called Rocket Science, led by the RHS Campaign for School Gardening, in partnership with the UK Space Agency.

RHS manager Alana Cama said, “The Rocket Science experiment opened a window into space biology and allowed young people to be at the forefront of creative research.”

“This research project did more than just inspire; it furthered our understanding of the challenges around growing plants in unusual environments and the possibility of growing food on long-term space missions in the future. Inspiring a new generation of botanists and biologists will remain our goal to enrich everyone’s lives through plants.”

Why do we laugh and get amusement from so many different things, from puns(双关语) to pratfalls(出洋相)? Why are things funny to some people and not to other? How is it that while a successful joke can cause pleasure, a sick one can cause serious harm?

Over the centuries, various scholars have tried to produce a universally agreed-upon theory of humor. Plato and Aristotle introduced the superiority theory, the idea that people laugh at the misfortune of others. Their theory seems to explain teasing, but it doesn't work well for knock-knock jokes. Sigmund Freud argued for his relief theory, the concept that humor is a way for people to release psychological tension and reveal their inner fears and desires. His theory works well for dirty jokes, less well for most puns.

The majority of humor experts today agree with the incongruity(不和谐) theory, the idea that humor arises when there's a gap between what people expect to happen and what actually happens. Incongruity has a lot going for it-jokes with unexpected funny lines, for example, fit well. But scientists have found that in comedy, unexpectedness is overvalued.

With the goal of developing a new, more satisfactory explanation, I produced “the gentle violation(侵犯) theory”, the idea that humor arises when something seems wrong or threatening, but is actually OK or safe. A dirty joke, for example, trades on moral or social violations, but it's only going to get a laugh if the person listening is open enough to consider the subject OK to talk about. Similarly, puns can be seen as linguistic violations that still make grammatical sense.

And while most humor theories have struggled to explain tickling (挠痒痒),or just avoided the phenomenon altogether, my theory accounts for even this kind of laughter. Tickling involves violating someone's physical space in a gentle way. People can't tickle themselves - because it isn't a violation.

Scroll through social media sites such as Instagram, Twitter or Facebook and you will be confronted with picture after picture of perfectly presented and delicious-looking meals. While the smell and taste of food can have an undeniably powerful effect on our cravings, are endless posts of steaming snacks more than just a feast for our eyes?

Our eating habits are influenced by what we see. “There is some evidence that, if you see pictures of food, that visual stimulation can prompt you to feel a desire to eat,” says Suzanne Higgs, a professor in the psychobiology of appetite. “If all your fiends on social media are posting pictures or livestreaming of themselves consuming fast food, it’s going to set a norm that eating fast food is what people do.” says Higgs.

Scientists are becoming increasingly concerned that food-related content on social media is making us think differently about food. Social media algorithms promote content that users engage with more, so viewing more unhealthy food means seeing more of it on our social media feeds.

It seems that healthier foods are often seen as boring in comparison, says Tina Tessitore, associate professor of marketing, “In advertising, you see unhealthy food in social settings—people having a barbecue with friends, for example, while healthy food often focuses more on the nutritional value. If you saw friends eating salad together, it would seem so incredible,” she says.

But while studies have found that social media can make us think differently about food, and that we typically engage more with content featuring unhealthy food, it’s uncertain yet whether this actually translates to our changes in our behavior in daily life. “If I’m scrolling through Instagram, looking at photos of tasty food, whether I seek out the food depends on how hungry I am, and whether it’s appropriate in that moment,” says Higgs. And when we do eat, we’re influenced by more than what we’ve seen online, she adds.