It's a popular belief that a fish's memory lasts for only seven seconds. It may seem sad to think that they don't remember what they've eaten or where they've been, and they don't recognize you or any of their friends — every moment in their life would be like seeing the world for the first time.

    But don't be so quick to feel sorry for them. A new study has found that fish have a much better memory than we used to think. In fact, certain species of fish can even remember events from as long as 12 days ago.

    In the study, researchers from MacEwan University in Canada trained a kind of fish called African cichlids to go to a certain area of their tank to get food. They then waited for 12 days before putting them back in the tank again.

    Researchers used computer software to monitor the fish's movements. They found that after such a long break the fish still went to the same place where they first got food. This suggested that they could remember their past experiences.

    In fact, scientists had been thinking for a long time that African cichlids might have a good memory. An earlier study showed that they behaved aggressively（挑衅地） in front of certain fish, perhaps because they remembered their past “fights”. But until the latest findings, there was no clear evidence.

    Just as a good memory can make our lives easier, it also plays an important part when a fish is trying to survive in the wild.

    “If fish are able to remember that a certain area contains safe food, they will be able to go back to that area without putting their lives at risks,” lead researcher Trevor Hamilton told Live Science.

    For a long time, fish were placed far below chimpanzees, dolphins and mice on the list of smart animals. But this study has given scientists a new understanding of their intelligence.

    Finding out what kind and how much physical activity you need

    How do I do it?

    It's your choice. Pick an activity that's easy to fit into your life. Do at least 10 minutes of physical activity at a time. Choose aerobic activities that work for you. These make your heart beat faster and can make your heart, lungs, and blood vessels fitter. Also, do strengthening activities which make your muscles do more work than usual.

    Why should I be physically active?

    Physical activity can make you feel stronger and more alive. It is a fun way to be with your family or friends. It also helps you improve your health.

    How many times a week should I keep physically active?

    It is up to you, but it is better to spread your activity throughout the week and to be active at least 3 days a week.

    How do I build up more physical activity?

    Do a little more each time. Once you feel comfortable, do it more often. Then you can trade activities at a moderate level for vigorous ones that take more effort. You can do moderate and vigorous activities in the same week.

    Movie Nights at the Museum brings you classic movies in a classic location. Each film has been chosen for its connection to an area of our knowledge.

We start this movie season with ocean-inspired cinema to celebrate the arrival of the noble blue whale in the Museum's typical hall, the site for the series.

    So get your popcorn, take your seat, and settle in for Movie Nights at the Museum.

Jaws

    Did you know that great whites actually find the taste of human flesh not tasty? However, this legendary Steven Spielberg thriller sees a giant great white shark cause destruction on the shores of a New England beach town in the mid-1970s.

Free Willy

    Did you know that the killer whale is not a whale? It's actually a dolphin. In this heart-warming 90s classic, orphan Jesse makes friends with a trapped killer whale and does whatever it takes to return him to his family and ocean home.

Finding Nemo

    Contrary to popular belief, fish are actually good at remembering things. Follow young clownfish Nemo, taken unexpectedly from his Great Barrier Reef home, and his father and forgetful partner who go on a brave journey to find him, in this charming Disney adventure.

The Little Mermaid

    In this classic Disney tale of a mermaid princess who dreams of becoming human, Ariel falls in love with a handsome prince, much to the sadness of her father and long-suffering friends. But did you know that a fish is actually brown and flat, with both eyes on one side of its body?

Ticket: £ 28, Member: £ 25.

    The Hawaii Volcanoes National Park

The Hawaii Volcanoes National Park, on the island of Hawaii, has two active volcanoes: Mauna Loa, which last erupted (喷发) in 1984, is 13,677 feet (4.17 km) above sea level; Kilauea is next to Mauna Loa and it has been erupting since January 3rd, 1983. It is 4,190 feet (1.23 km) above sea level.

When to visit

    The park is open 24 hours a day all year round. There are no plants or trees on the lava (火山岩) fields and no protection from the sun, so you must bring sunscreen (防晒霜).

    How to get there

    The best way to get to the park is to take Highway 11. From the airport at Hilo, Highway 11 will take you southward across the eastern part of the island.

    Things to see

    If you want to know more about the park, the Kilauea Visitor Center is surely a stop to make. It is a quarter of a mile (402 m) from the park entrance. There, you can see a great movie about real lava and learn about the island's natural and cultural history. The center is open from 7:45 a.m. to 5:00 p.m. There are also many guided walks and hikes around the park. You must check weather conditions and volcanic activity before hiking alone. If possible, you may drive down Chain of Craters Road to see lava flowing into the ocean.

    Tickets

    Entrance to the park is $10.00 for each vehicle, $5.00 for those who travel on foot or ride a bicycle. Children under the age of 15 are free.

    Gabriella's family immigrated to the US from Peru when she was two years old. As a compound bilingual (双语使用者), Gabriella develops two linguistic codes at the same time, with a set of concepts, learning both English and Spanish. Her teenage brother, on the other hand, might be a coordinate bilingual, working with two sets of concepts, learning English in school, Spanish at home. Finally, Gabriella's parents are likely to be subordinate bilinguals who learned a second language by translating it into their mother tongue.

    Regardless of accent and pronunciation, all types of bilingual people can become fully proficient in a language. It seems that the difference may not be apparent. But recently brain imaging technology has given a glimpse into how specific aspects of language learning affect the bilingual brain. It's well known that the brain's left hemisphere (半球) is in charge of logical processes, while the right hemisphere is more active in emotional and social ones. Language involves both types of functions. "Critical Period Theory" says children learn languages more easily because their developing brains let them use both hemispheres in language learning, while in most adults, language relies on one hemisphere, usually the left.

    Before the 1960s, bilingualism was considered a handicap that slowed the children's development by forcing them to spend too much energy distinguishing between languages. But a recent study did show that bilingualism may make you smarter. It does make your brain more complex, healthier, and more actively engaged, and even if you didn't have the good fortune of learning a second language like a child, it's never too late to do yourself a favor and make the linguistic leap from "Hello" to "Hola" "Bonjour" or "nihao" because when it comes to our brains, a little exercise can go a long way.

D

With the completion of the Human Genome（基因组）Project more than 20 years ago, and the discovery of the double helix structure of DNA enjoying its 70th birthday last year, you might assume that we know how life works. Think again!

Evolution has a 4bn-year head start on us. However, several aspects of the standard picture of how life works-the idea of the genome as a blueprint, of genes as instructions for building an organism, of proteins as precisely tailored molecular（分子）machines and more-have wildly reduced the complexity of life. 

In the excellent book How Life Works, Philip Ball explorers the new biology, revealing life to be a far richer, more delicate affair than we have understood. Ball explains that life is a system of many levels-genes, proteins, cells, tissues, and body modules-each with its own rules and principles, so there is no unique place to look for an answer to it. 

Also, How Life Works is a much more appealing title than the overused question of "What is life?". We should be less concerned with what a thing is, and rather more focused on what a thing does. Defining a living thing implies an unchangeable ideal type, but this will run counter to the Darwinian principle that living things are four-dimensional, ever changing in time as well as space.

But it's an idea that is deeply rooted within our culture. Ball points out that we rely on metaphors（比喻）to explain and explore the complexities of life, but none suffice. We are taught that cells are machines, though no machine we have invented behaves like the simplest cell; that DNA is a code or a blueprint, though it is neither; that the brain is a computer, though no computer behaves like a brain at all.

Ball is a terrific writer, pumping out books on incredibly diverse subjects. There's a wealth of well-researched information in here, and some details that are a bit chewy for the lay reader. But the book serves as an essential introduction on our never-ending quest to understand life.