It may not change how you buy bananas, but scientists have voted to redefine the value of a kilogram, in what they called a landmark decision that will boost the accuracy of scientific measurements. Since 1889, a kilogram has been defined by a shiny lump of platinum-iridium kept in a special glass case and known as the International Prototype of the Kilogram. It is housed at the headquarters of the International Bureau of Weights and Measures (whose French acronym is BIPM), just outside Paris.
Members of the BIPM, which groups 60 nations, agreed on Nov. 16 after a week-long meeting at the nearby Palace of Versailles to redefine the kilogram in terms of a tiny but unchanging value called the “Planck constant.” They also voted to update definitions for the ampere (electrical current), the kelvin (thermodynamic temperature) and the mole (amount of a substance).
All modern mass measurements are derived from the kilogram, whether micrograms of pharmaceutical medicine or gold dust, kilos of fruit or fish, or tonnes of steel. The problem is that the prototype doesn’t always weigh the same. Even inside its three glass bell jars it picks up microparticles of dirt and is affected by the atmosphere. Sometimes it needs cleaning, which can affect its mass.
Photo: EPA
照片：歐新社
That can have profound implications. If the prototype were to lose mass, atoms would in theory weigh more since the base kilogram must by definition always weigh a kilogram. Scientists have been trying for decades to define a constant value for the kilogram that is derived from immutable physics, in the same way they have done for other standard units (SI units) overseen by the BIPM.
For example, a meter isn’t 100 centimeters, it’s actually “the length of the path travelled by light in a vacuum during a time interval of 1/299,792,458 of a second.” The “Planck constant,” which derives from quantum physics, can be used along with a Kibble balance, an exquisitely accurate weighing machine, to calculate the mass of an object using a precisely measured electromagnetic force.
“The SI redefinition is a landmark moment in scientific progress,” said Martin Milton, director of the BIPM. “Using the fundamental constants we observe in nature as a foundation for important concepts such as mass and time means that we have a stable foundation from which to advance our scientific understanding, develop new technologies and address some of society’s greatest challenges.”
Barry Inglis, who heads the committee for weights and measures, said the implications were immense. “We will now no longer be bound by the limitations of objects in our measurement of the world, but have universally accessible units that can pave the way to even greater accuracy, and even accelerate scientific advancement,” he said.
It is arguably the most significant redefinition of an SI unit since the second was recalculated in 1967, a decision that helped ease communication across the world via technologies like GPS and the Internet. The new definitions agreed by the BIPM will come into force on May 20, next year.(Reuters)
這個改變或許不會影響你買香蕉的方式。不過，在日前一項被譽為有望提升科學測量準確度的劃時代決定中，科學家表決通過對一公斤的數值重新定義。自一八八九年以來，一公斤的重量由一塊鉑銥合金定義，這塊閃閃發光的金屬稱作「國際公斤原器」，被保存在特別的玻璃櫃中，目前存放於巴黎近郊的國際度量衡局（法文首字母縮寫為「BIPM」）總部。
來自大約六十個國家的國際度量衡局會員，日前齊聚鄰近的凡爾賽宮，召開長達一星期的會議，並於十一月十六日做出決議：根據微小卻不會變動的「普朗克常數」數值，重新定義一公斤。會員們也決議更新安培（電流）、克耳文（熱力學溫度）以及莫耳（物質的量）等單位的定義。
無論是藥學醫療或是砂金使用的微公克（一公克的百萬分之一）、買水果或是賣魚時使用的公斤，還是鋼鐵的公噸，現代的各種質量測定都衍生自公斤。問題在於，「國際公斤原器」無法一直維持相同的重量。就算保存在三層鐘型玻璃罩裡面，原器還是會沾染灰塵的微粒子，也會受大氣影響。有時原器需要清潔，這又會影響其質量。
這個問題的牽涉層面相當廣泛：如果原器損失質量，理論上原子就會變重，畢竟這個基礎公斤在定義上就是重達一公斤。數十年來，科學家一直試圖藉由恆常不變的物理學，用一個固定的數值定義公斤，這也是他們先前在國際度量衡局監督下為其他標準單位（國際單位制）完成的相同目標。
舉例而言，一公尺並非一百公分，實際上應為「光在真空中於兩億九千九百七十九萬兩千四百五十八分之一秒內行進的距離」。從量子力學中導出的「普朗克常數」可以和極度精確的秤重儀器「基布爾秤」一起應用，藉由精準測量出的電磁力來計算一個物體的質量。
國際度量衡局的局長馬汀‧米爾頓表示：「對於國際單位制的重新定義是科學進展過程中的重大里程碑。」他也進一步指出：「藉由運用我們在自然中觀察到的物理常數，作為質量、時間等重要概念的根基，這意味著我們能夠在穩固的基礎上取得科學知識進展、發展新科技，並且應對社會上最艱困的挑戰。」
國際度量衡委員會的會長貝瑞‧英格里斯指出，這項決議背後的含義重大：「從今以後，我們對世界的測量將不會受限於物體的侷限性，反而能夠擁有舉世可得的各種單位，為更加精準的測量鋪下坦途，甚至是加速科學發展。」
就國際單位制而言，這項決議可以說是自一九六七年重新計算「秒」後，最具意義的重新定義。當年重新計算「秒」的決議，協助了全球定位系統和網路等科技發展，讓全球的通訊系統大獲進展。國際度量衡局此回通過的多項新定義將自明年五月二十日生效。（台北時報章厚明譯）
Street lights are often taken for granted until a power outage plunges the world into darkness. When that happens, the value of these lighting installations becomes evident as the world turns into a more dangerous place for pedestrians and motorists alike. The Chinese could claim to be the first to have constructed a crude type of street light. Around 500 BC, residents of Beijing employed a type of street lamp that used hollow bamboo pipes and natural gas vents to create burning torches. Later, ancient Romans adopted lamps fueled by vegetable oil, which relied on slaves to light and
A: Who else is on Billboard’s list: “The 25 greatest pop stars of the 21st Century?” B: No. 15 to 6 are: Miley Cyrus, Justin Timberlake, Nicki Minaj, Eminem, Usher, Adele, Ariana Grande, Justin Bieber, Kanye West and Britney Spears. A: I can’t believe that Adele’s only at No. 10. B: No. 5 to 1 are: Lady Gaga, Drake, Rihanna, Taylor Swift and Beyonce. A: Well, they surely deserve the honor. A: 《告示牌》雜誌的「21世紀最偉大的25位流行歌手」，還有誰上榜啊？ B: 第15至6名是：麥莉希拉、大賈斯汀、妮姬米娜、阿姆、亞瑟小子、愛黛兒、亞莉安娜、小賈斯汀、肯伊威斯特、小甜甜布蘭妮。 A: 真不敢相信愛黛兒只排第10名。 B: 第5至1名是：女神卡卡、德瑞克、蕾哈娜、泰勒絲、碧昂絲。 A: 這幾位真是實至名歸！ （By Eddy Chang, Taipei Times／台北時報張聖恩）
A: The 21st Century is now entering its 25th year. B: So Billboard has released a list: “The 25 greatest pop stars of the 21st Century.” A: Who are the greatest pop singers? B: No. 25 to 16 are: Katy Perry, Ed Sheeran, Bad Bunny, One Direction, Lil Wayne, Bruno Mars, BTS, The Weeknd, Shakira and Jay-Z. A: Wow, my favorite K-pop supergroup BTS has made it to the list. A: 21世紀正在邁入第25個年頭了。 B: 《告示牌》雜誌特別公布：「21世紀最偉大的25位流行歌手」。 A: 最偉大的歌手有哪些？ B: 第25至16名是：凱蒂佩芮、紅髮艾德、壞痞兔、1世代、小韋恩、火星人布魯諾、防彈少年團（BTS）、威肯、夏奇拉、Jay-Z。 A: 哇，我最愛的韓流天團BTS也上榜了！ （By Eddy Chang, Taipei Times／台北時報張聖恩）
Spoiler alert and shift blame 破梗&甩鍋 在新冠疫情期間，無論是因為封城 (lockdown) 還是居家隔離 (self-isolation at home)，人們關在家中使用網路的時間大增。這也讓一些原本只存在於網路論壇的用語廣為普及。我們來談一下破梗 (spoiler alert) 與甩鍋 (shift blame) 這兩個用語。 有位古典文學教授 Joel Christensen 針對領導統御與疫情控制寫了一篇以古喻今、相當深入的文章：“Plagues follow bad leadership in ancient Greek tales”，文中出現一些講法，可用來翻譯上述的流行語： In the 5th century B.C., the playwright Sophocles begins Oedipus Tyrannos with the title character struggling to identify the cause of a plague striking his city, Thebes. (Spoiler alert: It’s his own bad leadership.) (Joel Christensen, “Plagues follow bad leadership in ancient Greek tales,” The Conversation, March 12, 2020) 作者提到 Oedipus（伊底帕斯）想找出瘟疫何以降臨他的城邦的緣由，加了一句：Spoiler alert: It’s his own bad leadership.（破梗：領導無方）。Spoiler alert 就是「破梗」，如果用在有人洩漏電影劇情的情境中，也可以翻作「小心爆雷」或「劇透警告」。疫情之下，在家看影集、電影成了很多人的娛樂，但要小心劇透 (spoilers)，很多 YouTube 上的影評在開頭也都會說 Spoiler alert!，警告還沒看過電影的觀眾小心爆雷、劇透。 至於「甩鍋」，源自大陸網民用語，通常意指某人犯了錯之後想推卸責任、轉移焦點、甚至讓別人背黑鍋的做法。疫情爆發後，相關網路資訊量爆增，許多中國網民也想找人為這場疫情負責，紛紛呼籲地方政府首長、地方黨書記不要「甩鍋」。 其實，在古代文學《奧德賽》中，就有「將自己的責任怪罪眾神」的說法，試用時下流行的「甩鍋」來重新翻譯： Humans are always blaming the gods for their suffering, but they experience
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