A warm drink of milk before bed has long been the best choice for those wanting a good night's sleep. But now a study has found it really does help people nod off—if it is milked from a cow at night.

       Researchers have discovered that “night milk” contains more melatonin(褪黑激素), which has been proven to help people feel sleepy and reduce anxiety.

       The study,by researchers from Seoul, South Korea, involved mice being fed with dried milk powder made from cows milked both during the day and at night.

       Those givennight milk, which contained 10 times the amount of melatonin, were less active and less anxious than those fed with the milk collected during daytime, according to the study published in The Journal of Medicinal Food.

       Night milk quickened the start of sleep and caused the mice to sleep longer.

       While the effect of cows milk harvested at different time has not been tested on humans up to now, taking melatonin drugs has been suggested to those who are struggling to fall asleep at night.

Previous studies have also indicated that milk can be excellent for helping sleep because of the calcium content, which helps people to relax.

       Milk is also sugar-free and additive-free with nutritionists recommending skimmed milk as the best choice before bed as it is the least fattening. The more fat you take in before bedtime, the greater burden you will put on your body at night.

    Valentine's Day, a day traditionally reserved for expressing romantic love, is observed practically all around the world. However, not many people are familiar with Sweetest Day. Actually it is a holiday, especially designed to express love and care for those who were routinely neglected（忽视）by society.

Sweetest Day was the idea of Herbert Birch Kingston, who worked for a company in Cleveland, Ohio. He felt that there were plenty of children, especially orphans and poor kids, who didn't necessarily get the attention they deserved. Thus in 1922, he launched the first Sweetest Day to give out boxes of candy to mainly poor children.

    Since the day picked was the third Saturday in October, this became the traditional time to celebrate Sweetest Day. The tradition was so enjoyed that people often looked beyond kindness to treating their own friends or family to treats on Sweetest Day.

    In the US, Sweetest Day is celebrated primarily in the Northeastern region of the US, still on the third Saturday of October. Yet news of the tradition, which began nearly 100 years ago, has spread to other parts of the country, especially as people who lived in those areas moved elsewhere. People may distribute candy or small gifts to those in patient homes, hospitals, foster homes, or mental institutions, and they may also treat friends and family to little gifts from the heart.

    In keeping with the original tradition, celebrating Sweetest Day should really be most focused on people who ordinarily don't have the good fortune of attention from friends or family, either due to difficult family circumstances or to poverty. This can be a great tradition to start if your community doesn't routinely celebrate the day, and there are many candy manufacturers that are willing to help donate or reduce costs on gifts intended for people in unfortunate circumstances.

    The United Arab Emirates (UAE) is mostly a desert. However, this has not stopped the country from creating great building projects. On September 26, UAE officials announced another ambitious project — Mars Science City. Expansive deserts and miles of coastline provide plenty of options for safe rocket launches (发射). And its position on the Earth makes it especially appealing as the spin of the Earth provides an extra push, meaning less fuel is needed to get payloads into orbit. All these seem to make it possible.

    The Mars City Project, designed by Bjarke Ingels Group, or BIG, will provide a realistic model to simulate (模仿) living on the surface of Mars, the red planet. It is part of the UAE's Mars 2117 Project to lead the global race to land humans on Mars and be the first to build a settlement there. Sheikh Mohammed bin Rashid, Prime Minister and ruler of Dubai, says, “The UAE seeks international support to develop technologies that benefit humans, and lay the foundation of a better future for more generations to come.”

    Built outside Dubai, the 1.9 million square feet city is expected to cost $135 million. It will consist of several dome-shaped laboratories, similar to the ones imagined for the first Mars settlers. Scientists from around the word will be invited to conduct research to come up with methods to create food, water and energy, using techniques which can be copied onto the red planet. The living spaces, where the researchers can live for up to a year, will simulate the planet's conditions as much as possible.

    The research city will also include a museum featuring famous space achievements to help educate and inspire children to undertake space exploration and discovery. To discover whether the construction method works on Mars, the museum's walls will be 3D printed using the sand from the nearby desert. Now, if they would only add some living quarters for the general public to experience life on Mars without leaving Earth, life would be perfect.

    There are so many expressions in American English that sound pleasant but are not.

    “Face the music” is a good example. When someone says they have to face the music, it does not mean they are going to a musical performance or concert. To face the music means to accept the unpleasant results of an action.

    Imagine a friend asks you to take care of her beautiful red sports car. She gives you the keys and says, “Thanks so much for watching my car while I'm away. But please do not drive it. It is an extremely fast car and you are not on the insurance (保险).”

    But you do not listen. You want to show off to some friends and pretend the car is yours. So, you drive it around town one night. As bad luck would have it, you lose control of the car and drive it into a stop sign. The damage is severe. When your friend returns you must tell her what you have done and “face the music”.

    The “music” here is the consequence or result of your actions. It could be losing her friendship or paying for repairs to her sports car or both. Whatever the music is, you must face it.

    There are other American expressions that mean the same as “face the music”.

    To “take your medicine” means to accept the results from something bad you have done. And if someone says, “You made your bed. Now lie in it.” He means you created a bad situation and now you will experience the results, or as we say in American spoken English, you must deal with it!

    “Pay the piper” also means the same as “face the music”. But, that expression has its own very interesting beginning. We will talk about that on another Words and Their Stories.

    Here are our suggestions for keeping busy this week. Dive in!

    Take to the waves in Southampton

    Always fancied trying your hand at sailing? Now's your chance. The Southampton Boat Show has plenty of opportunities for visitors to get out on the water to experience boat sailing, power boating or taking a ride on a RIB ― all for free.

    Discover an island on the Thames

    To celebrate Totally Thames, a month-long festival is held at various locations across London. We've discovered 21 of the river's most fascinating islands ― all of them with interesting stories to tell. Make the most of it with our map here.

    Catch great films in Bristol

    Over six days, Encounters Film Festival screens up to 400 films from over 60 different countries. The Bristol festival provides a platform for international filmmakers, and offers a gateway to the likes of the BAFTAs, Oscars and European Film Awards. See here for full details.

Get scientific in London

    Experience the latest, best and most challenging science covering all areas of our lives and universe at New Scientist Live at ExCel London. New Scientist Live is a four-day festival full of ideas and discoveries from the team behind the world's most popular science weekly magazine, featuring four zones Brain & Body, Technology, Earth and Universe as well as talks from experts and over 200 exhibitors.

    We now think that chocolate is sweet, but once it was bitter. We think of it as a candy, but once it was a medicine. Today, chocolate can be a hot drink, a frozen dessert, or just a snack. Sometimes it's an ingredient（构成部分）in the main course of a meal. Mexicans make a hot chocolate sauce called Mole and pour it over chicken. The Mexicans also eat chocolate with spices like chili peppers.

    Chocolate is a product of the tropical cacao tree. The beans taste so bitter that even the monkeys say "Ugh!" and run away. Workers must first dry and then roast the beans. This removes the bitter taste.

    The word "chocolate" comes from a Mayan word. The Mayas were an ancient people who once lived in Mexico. They valued the cacao tree. Some used the beans for money, while others crushed them to make a drink.

    When the Spaniards came to Mexico in the sixteenth century, they started drinking cacao, too. Because the drink was strong and bitter, they thought it was a medicine. No one had the idea of adding sugar. The Spaniards took some beans back to Europe and opened cafes. Wealthy people drank cacao and said it was good for the digestion.

    In the 1800s, the owner of a chocolate factory in England discovered that sugar removed the bitter taste of cacao. It quickly became a cheap and popular drink. Soon afterwards, a factory made the first solid block of sweetened chocolate. Later on, another factory mixed milk and chocolate together. People liked the taste of milk chocolate even better.

    Besides the chocolate candy bar, one of the most popular American snacks is the chocolate chip cookie. Favorite desserts are the chocolate cream pie and, of course, an ice cream sundae with hot fudge sauce.