【推荐1】Scroll through social media sites such as Instagram, Twitter or Facebook and you’ll 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 appetite, 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 psycho biology of appetite. “If all your friends on social media are posting pictures or live streaming 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 (社交媒体算法) 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 wouldn’t seem so credible,” 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.

【推荐2】“Snap, snap”, went Emily’s phone as she took a photo of her avocado toast for breakfast. Then, she posted it on Instagram, a popular social photo-sharing app. Emily is one of the millions of millennials — those born between the years 1981 and 1996 – in the West who are in love with avocados.

So why is the avocado, a green-colored fruit with a rough black outer shell originating from Mexico, loved so much by millennials?

At the start of the last century in the US, avocados weren’t popular. But this changed thanks to good marketing. Firstly, their name was changed from “alligator pear” to the nicer-sounding “avocado”. Then in the 1990s, at the Super Bowl – the US’ famous annual sports event watched by tens of millions on TV – a Mexican sauce made with avocados called guacamole was advertized. After this, avocados’ popularity soared. According to the Canadian Broadcasting Corporation, the value of avocados increased by nearly 70 percent between 1988 and the year 2000 in the US.

But it wasn’t until the 2010s, when millennials started the avocado toast trend that it became a fruit celebrity. Avocados, as a superfood rich in nutrients and “good” fats, are perfect for millennials, who are regarded as a health-conscious generation. As reported by USA Today, millennials are more interested in food than previous generations. For them, eating is not just about feeling full; it’s about a lifestyle. They care more about their well-being and eat healthier and more plant-based foods.

Of these foods, avocado toast is the poster child. On a list of the top 25 millennial food trends, Therecipe.com ranked avocado toast as number one. Millennials are a social-media- savvy generation. They love sharing their lives online through artistic pictures. The vibrant green-colored avocado spread on toast for breakfast became very Instagrammable. The avocado craze hasn’t stopped with eating. Searching online, you’ll find endless results for avocado-themed items. In 2019, Disney even released a line of avocado-themed merchandise.

Trends always come and go. But the millennials’ avocado trend isn’t showing any signs of disappearing anytime soon.

【推荐1】In the 1950s, a plastic surgeon (整形外科医生) by the name of Maxwell Maltz began to notice that many of his patients took about 21 days before they got used to seeing their new face after an operation-like a nose job, for example.

These experiences finally led Maltz to publish a book in the 1960s, in which he stated that “ it requires a minimum of about 21 days for an old mental image to disappear and anew one to become clearer”. The book sold more than 30 million copies and is still in print today.

This “2l days” figure has been repeated countless times ever since. It has been republished in thousands of self-help books and TV shows.

There’s a problem though. The “21 days” time window for strengthening changes inhabit is less a statistical fact and more like a myth.

In 2009, researchers at the University of College London led by Phillippa Lally examined changes in the habits of 96 people over a 12-week period, Each person had to choose a new habit they wanted to internalize (使内在化) and reported each day on whether or not they had performed an activity related to the behavior and how routine it felt. After 12 weeks, the study came to a close and the researchers used statistical methods to interpret the data they had gathered, Their assessment blew Psycho-Cybernetics out of the water, showing that the time it took to form a new habit ranged from 18 to 254 days.

ALONG LINE OF MYSTERIES

Along a special line of latitude, known as the 30th parallel north lie numerous sites of ancient cvilisations and impressive natural features. Ancient civilisations appeared on the parallel, including Babylon, with its famous tower: Egypt with its pyramids.

China, with its Sarangdui culture, etc. These cvilisations appeared at a similar time, and all developed advanced bronze-making techniques. Were they part of a single super-civilisation as some think?

It’s argued that the 30th parallel north is a line of great natural energy, with frequent earthquakes and volcanic eruptions. This creates amazing natural features, including Mount Qomolangma the Dead Sea and rivers, such as the Nile, the Mississippi and the Yangtze. Lacking any concrete evidence, some even claim it was supernatural powers!

Scientists, however, dispute these theories. It’s more likely they argue, that civilisations arose on the 30th parallel north because the climate there is generally warm and damp. Major tectonic plates meet at this latitude, causing earthquakes, which helped form the Himalayas. The rest they say, is either coincidence or fantasy.

【推荐1】Sending rockets into space requires sacrificing expensive equipment, burning massive amounts of fuel, and risking potential catastrophe. So in the space race of the 21st century, some engineers are abandoning rockets for something much more exciting: elevators.

Imagine hopping on a fast-spinning carousel (旋转木马) while holding a rope attached to a rock. As long as the carousel keeps spinning, the rock and rope will remain horizontal, kept in the air by centrifugal force (离心力). If we replace the carousel with the Earth, the rope with a long cable, and the rock with a counterweight, we can imagine the modern space elevator—a cable pulled into space by the physics of our spinning planet. For this to work, the counterweight would need to be far enough away that the centrifugal force generated by the Earth’s spin is greater than the planet’s gravity. These forces balance out at roughly 36,000 kilometers above the surface, so the counterweight should be beyond this height. The resultant force on objects at this specific distance is evidently zero, leaving the objects in geostationary orbit, which means they revolve around the Earth at the same rate the planet spins, thus appearing motionless in the sky.

The counterweight itself could be anything. From here, the cable could be released down through the atmosphere and connected to a base station on the planet’s surface. To maximize centrifugal acceleration, this anchor point should be close to the Equator. And by making the loading station a mobile ocean base, the entire system could be moved at will, allowing it to perform around extreme weather, and avoid satellites in space. Once established, cargo could be loaded onto devices called climbers, which would pull packages along the cable and into orbit.

But the main problem lies in the cable itself. In addition to supporting a massive amount of weight, the cable’s material would have to be strong enough to stand the counterweight’s pull. And because this tension and the force of gravity would vary at different points, its strength and thickness would need to vary as well. But so far, we’ve only been able to manufacture very small nanotube (纳米碳管) chains.