【推荐2】In February 2015, a photograph of a dress raised heated debate around the world. The disagreement centred on the dress’s colour: some people were convinced it was blue and black while others white and gold. People couldn’t understand how, faced with exactly the same photograph of exactly the same dress, they could reach such different conclusions.

For a long time, people believed that colours were objective, physical features of objects or of the light that was reflected off them. But this theory isn’t really true. Different wavelengths of light do exist independently of us but they only become colours inside our bodies. Every person’s visual system is unique and so are their perceptions (感知). This is why no two people will ever see exactly the same colours.

Another cause of the problem is language. People generally name only the colours they consider socially or culturally important. In English we divide colour space into 11 basic terms — black, white, red, yellow, green, blue, purple, brown, grey, orange and pink — but other languages do things differently. At least one Indigenous community has no specific words for any colours, only “light” and “dark”. The Aztecs, who were enthusiastic farmers, used more than a dozen words for green.

A single colour can mean completely different things in different places and at different times. In the west white is the colour of light, life and purity, but in parts of Asia it is the colour of death. Many people today think of blue as masculine (男性的) and pink as feminine (女性的), but only a hundred years ago baby boys were dressed in pink and girls in blue.

All of this taken together, it becomes rather difficult to reach a conclusion different from that of the 18th-century philosopher David Hume: colour is merely a phantasm of the senses.

【推荐2】African penguins stand only 50 cm tall. Like people, each penguin has its own voice. They live along the southern coast of Africa. Like all the other penguins, they hunt fish in the ocean and lay eggs on land. But they are smaller than their well-known cousins in Antarctica (南极洲) and larger than little penguins in Australia and blue penguins in New Zealand. But the African penguins have a problem—they are endangered.

The African penguins used to nest (筑巢) underground in the bird poop (粪便), which came from the penguins and other seabirds. Over hundreds of years, it had built up to form a thick layer as deep as 3 meters.

However, in the 1860s, people began collecting the poop to use it on farms. Now there’s no more poop to make nests. The penguins have to lay their eggs in the open. As a result, the penguins often get too hot. When the parents leave the eggs to cool themselves down in the water, other animals can easily find the eggs and eat them.

To solve the problem, the scientists set up an artificial nest project in 2016. They came up with criteria for the nest. It had to protect penguin eggs from being eaten. It couldn’t flood in the rain. And it needed to keep penguin families cool. The scientists built 15 kinds of nests to find the perfect one. Finally two of them stood out. Both of them could let air flow through. The scientists plan to build more than 2,500 nests for the African penguins in the future. They hope the new nests can help increase the number of the endangered birds.

【推荐3】When most people go to the famous amusement parks in Orlando, Florida, they miss some of the natural wonders the State has to offer. It was in Citrus County on the beautiful west coast of Florida that we went to see the manatee (海牛), which occupies coastal waters and rivers.

Our days started early in the morning at Homosassa Springs. We boarded a boat with Captain Traci Wood from Native Vacations. Having spotted two manatees just below the water, Captain Traci stopped the boat as they slowly swam toward us. They used their tails to drive themselves, steering with their flippers(脚蹼), gracefully moving their bodies through the water in our direction. Our boat was soon surrounded by other members of this gentle species.

Soon we continued our journey. Within a few minutes Captain Traci stopped the boat again and we were given instructions. Whatever you do, she said, remember the three golden rules: minimize splash (拍水) noise; act with very slow movements; and when you touch one of these friendly, gentle grey giants on the back or stomach, never touch with more than one hand at a time. The Endangered Species Act forbids touching a manatee unless it touches you first, and they will let you know. The protection of this endangered species is taken very seriously. But this won’t affect the experience in the least. Most Homosassa manatees are very social and will come to you.

Manatees feed strictly on plants, and they eat a great variety of species, including hyacinth and water lettuce. They’re very big, measuring 3 to 5 metres and weighing as much as 1,600 kilos. Despite this, they look very cute. Manatees are of course wild creatures, although when face to face with them, you’re unlikely to feel any fear.

From December to March, groups of manatees escape the cold winter ocean and bathe in the warm waters near power plants and coastal springs that stay about 23 degrees year-round. Divers and swimmers come to Florida from all over the world for a chance to swim or interact with the manatee in its natural environment, rich in marine vegetation. This rich source of food makes this area an ideal place for the manatees. So the manatees arrive every year by the hundreds to find warmth, nourishment(营养) and maybe, just maybe, to visit us, the curious humans.

【推荐3】Cultural differences do exist, and we can really use them to tighten our relationship as human beings. Because there is strength in diversity. So, we are going to expose some interesting cultural differences around the world in this article. Read some interesting cultures around the world to help you travel out of your homeland!

In Greece spitting (吐痰) at weddings is believed to drive away devil (恶魔). Funny as it sounds, this cultural tradition is an important practice. To make it even more shocking, this spitting is focused on the bride. It is seen as good luck to bless the couple. However, Things have been changed in some parts of Greece these days. Wedding guests just face the bride and make sounds and impressions that show they are spitting on her—without actually spitting.

Everybody knows the Thai people are so friendly, but their culture demands that you never point your feet at anyone of any statue, especially that of the Buddha. In addition, they also consider the head to be more important than other parts of the body. This is why it is disrespectful to touch another person’s head in Thailand. Statues are not left out. If you see the Buddha statue, avoid touching its head as well.

Russians are very hospitable (好客的) people. In their culture food is serious business. Lunch is the most important and heaviest meal. If you get invited by your Russian friend for a meal, don’t ever refuse it-they find it impolite. You might want to skip your own meals to leave space in your stomach for the food you will eat in Russian gatherings. This is very interesting cultural difference between Russian people and other nations.

Since there is limited knowledge about cultures outside your own, you won’t be able to really flow with a foreigner. Now, you know some about the cultural differences around the world, so we hope it will make your life easier.