When we think about happiness, we usually think of something surprising and unexpected, a top great delight.

    For a child, happiness has a magic quality. I remember playing police and robbers in the woods, getting a speaking part in the school play. Of course, kids also experience lows, but their delight at tops of pleasure is easily seen, such as winning a race or getting a new bike.

    For teenagers, or people under 20, the idea of happiness changes. Suddenly it's conditional on such things as excitement, love, and popularity. I can still feel the pain of not being invited to a party that almost everyone else was going to. I also recall the great happiness of being invited at another event to dance with a very handsome young man.

    In adulthood the things that bring great joy — birth, love, marriage — also bring responsibility and the risk of loss. Love may not last; loved ones die. For adults, happiness is complex.

    My dictionary explains “happy” as “lucky” or “ fortunate”, but I think a better explanation of happiness is “ the ability to enjoy something”. The more we can enjoy what we have, the happier we are. It's easy for us not to notice the pleasure we get from loving and being loved, the company of friends, the freedom to love where we please, and even good health. Nowadays, with so many choices and much pleasure, we have turned happiness into one more thing we have. We think we own the right to have it, which makes us extremely unhappy. So we try hard to get it and consider it to be the same as wealth and success, without noticing that the people who have those things aren't necessarily happier.

    While happiness may be more complex for us, the answer is the same as ever. Happiness isn't about what happens to us. It's the ability to find a positive for every negative, and view a difficulty as a challenge. Don't be sad for what we don't have, but enjoy what we do possess.

    Music for Humans and Humpback Whales (座头鲸)

    As researchers conclude in Science, the love of music is not only a universal feature of the human species but is also deeply fixed in complex structures of the human brain and is far more ancient than previously suspected.

    In the articles, researchers present various evidence to show that music-making is at once an original human “business”, and an art form with skillful performers throughout the animal kingdom.

    The new reports stress that humans hold no copyright on sound wisdom, and that a number of nonhuman animals produce what can rightly be called music, rather than random sound. Recent in-depth analyses of the songs sung by humpback whales show that, even when their organ would allow them to do otherwise, the animals converge on the same choices related to sounds and beauty, and accept the same laws of song composition as those preferred by human musicians, and human ears, everywhere.

    For example, male humpback whales, who spend six months of each year doing little else but singing, use rhythms (节奏) similar to those found in human music and musical phrases of similar length—a few seconds. Whales are able to make sounds over a range of at least seven octaves (八度音阶), yet they tend to move on through a song in beautiful musical intervals (间隔), rather than moving forwards madly. They mix the sounds like drums and pure tones in a ratio (比例) which agrees with that heard in much western music. They also use a favorite technique of human singers, the so-called A-B-A form, in which a theme is stated, then developed, and then returned to in slightly revised form.

Perhaps most impressive, humpback songs contain tunes that rhyme. “This suggests that whales use rhyme, the same way we do: as a technique in poem to help them remember complex materials,” the researchers write.

    Obama, Lady Gaga and Steve Jobs—what do they have in common? They are, of course, all Americans. And according to a survey by social networking site baidu.com, they all best illustrate the word “cool”.

    But just what does it mean to say someone is “cool”? Most would answer that it is something to do with being independent-minded and not following the crowd.

    Yale University art professor Robert Farris Thompson says that the term “cool” goes back to 15th century West African philosophy. “Cool” relates to ideas of grace under pressure.

    “In Africa,” he writes, “coolness is a positive quality which combines calmness, silence, and life.”

    The modern idea of “cool” developed largely in the US in the period after World War II. “Post-war 'cool' was in part an expression of war-weariness… it went against the strict social rules of the time,” write sociologists Dick Pountain and David Robins in Cool Rules: Anatomy of an Attitude.

    But it was the American actor James Dean who became the symbol for “cool” in the hugely successful 1955 movie Rebel without a Cause. Dean plays a tough guy who disobeys his parents and the authorities. He always gets the girl, smokes cigarettes, wears a leather jacket and beats up bullies. In the movie, Dean showed what “cool” would mean to American young people for the next 60 years.

    Today the focus of “cool” has changed to athletics stars. Often in movies about schools, students gain popularity on the athletics field more than in the classroom. This can be seen quite clearly in movies like Varsity Blues and John Tucker Must Die.

But many teenagers also think being smart is cool. Chess and other thinking games have been becoming more popular in schools.

    “Call it the Harry Potterization of America—a time when being smart is the new cool,” writes journalist Joe Sunnen.

    One of the most firmly established idea of manliness(男子汉) is that a real man doesn't cry. Although he might cry a bit at a funeral, he is expected to quickly regain control. Crying openly is for girls. One study found that women cry significantly more than men do—five times as often, on average, and almost twice as long per period.

    Historically, however, men usually cried, and no one saw it as shameful. For example, in the Middle Ages, knights(骑士) cried only because they missed their girlfriends. In The Knight of the Cart, no less a hero than Lancelot cries at a brief separation from Guinevere. There's no mention of the men in these stories trying to hold back or hide their tears. They cry in a crowded hall with their heads held high. Nor do other people make fun of this public crying; it's universally regarded as an expression of feeling to show love.

    So where did all the male tears go? The most obvious possibility is that this is the result of changes as we moved from an agricultural(农业的) society to one that was urban(城市的)and industrial(工业的). In the Middle Ages, most people spent their lives among those they had known since birth. If men cried, they did so with people who would sympathize(同情). But from the 18^th to 20^th centuries, the population became increasingly urbanize, and people were living in the midst of thousands of strangers. Furthermore, changes in the economy required men to work together in factories and offices where expressions of feelings and even personal conversations were discouraged as time wasting.

    Yet human beings weren't designed to hide their feelings, and there's reason to believe that restraining tears can be harmful to your well-being. Research from the 1980s has suggested a relationship between stress-related illnesses and not enough crying. Crying is also, somewhat related with happiness and wealth. Countries where people cry the most tend to be richer and more confident.

    "Make way, good people, make way, in the King's name! "cried he. "Open a text; and, I promise you, Mistress Prynne shall be set where man, woman, and child, may have a fair sight of her brave clothing, from this time till an hour past noon. A blessing on the moral Colony of the Massachusetts, where immorality is dragged out into the sunshine! Come along, Madam Hester, and show your scarlet （鲜红色的；罪孽深重的）letter in the market-place!

    A lane was at once opened through the crowd. Led by the beadle （狱吏），and attended by an irregular procession of serious-looking men and unkind-looking women, Hester Prynne set forth towards the place appointed for her punishment. A crowd of eager and curious schoolboys, understanding little of the matter in hand, except that it gave them a half-holiday, ran before her progress, turning their heads continually to stare into her face, and at the winking baby in her arms, and at the shameful letter on her breast.

    It was no great distance, in those days, from the prison-door to the market-place. Measured by the prisoner's experience, however, it might be considered to be a rather long journey; for, though her manner was proud, she perhaps underwent an extreme pain from every footstep of those who thronged to see her, as if her heart had been thrown into the street for them all to step upon. In our nature, however, there is a condition that the sufferer should never know the intensity of what he endures by its present suffering, but chiefly by the pain that rankles （使痛心）after it. With almost a calm manner, therefore, Hester Prynne passed through this portion of her suffering, and came to a sort of scaffold （刑台），at the western end of the market-place. It stood nearly beneath the eaves of Boston's earliest church, and appeared to be a fixture there.

    Throughout much of human history, man has been the measure of many, if not all, things. Lengths were divided up into feet and smaller units from the human hand. Other measures were equally characteristic. Mediterranean traders for centuries used the weight of grains of wheat to define (定义) their units of mass. The Romans used libra, forerunner of the pound, by referring to the weight of a carob (角豆树) seed.

    The sizes of similarly named units could also differ. The king's foot, used in France for nearly

    1,000 years after its introduction by Charlemagne in around 790 AD, was, at 32.5cm,around a centimeter shorter than the Belgic foot, used in England until 1300.Greek,Egyptian and Babylonian versions of water in a fixed container varied from one another by a few kilos, Nor was there agreement on such things within countries. In France, where there was no unified (统一的) measurement system at the national level, the situation was particularly terrible. The lieue (former measure of distance), for example, varied from just over 3 km in the north to nearly 6 km in the south.

    Although John Wilkins, an Englishman, first put forward a decimal system (十进制) of measurement in 1668,it was the French who in 1799 made it law. The Système International d'Unités (SI, or the metric system, as it is better known) developed from it and became the official measurement in all countries except Myanmar, Liberia and the United States. Now the International Bureau of Weights and Measures in Paris is set to give the metric system its biggest shake-up yet.

    At a meeting in Versailles, France, on November 16th,2018,the world's measurement bodies are almost certain to approve a decision that will mean four out of the seven base SI units, including the kilogram, will follow the other three, including the metre, in being redefined in terms of the values of physical constants (物理常数).Each of the chosen constants has been measured incredibly precisely, which would mean that from May 20^th 2019 the constants will themselves be fixed at their current values for ever. Any laboratory in the world will then be able to measure, for example, the mass of an object as precisely as the accuracy of their equipment will allow.