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隨著科學技術發(fā)展以及人們在互聯(lián)網(wǎng)上產(chǎn)生的海量數(shù)據(jù)，如何準確描述數(shù)據(jù)的大小成為科學家們的新課題，數(shù)量級的最大最小，該如何描述呢？
 

據(jù)美國全國公共廣播電臺（NPR）19日報道，第27屆國際計量大會近日宣布，國際單位制引入4個新的用于構(gòu)成十進倍數(shù)和分數(shù)單位的詞頭，分別擴展了最大和最小數(shù)字的計數(shù)單位，以應對科學進步和數(shù)據(jù)存儲量大增的需求。
 

新增的4個詞頭分別是ronna、quetta、ronto和quecto。其中，ronna表示數(shù)字后有27個零，quetta表示數(shù)字后有30個零。ronto和quecto則用于表示極小的數(shù)字，分別表示小數(shù)點后有27個零和30個零。而新增的4個單位詞頭能代表目前已測量過的最大和最小數(shù)據(jù)。
 

The 27th General Conference on Weights and Measures last Friday introduced four new prefixes to the International System of Units, or metric system: ronna (27 zeroes after the first digit) and quetta (30 zeroes), which are now at the top of the measurement range, and ronto (27 zeroes after the decimal point) and quecto (30 zeroes), which are now at the bottom.
 

英國國家物理實驗室度量衡學負責人理查德·布朗博士，向國際計量大會提出了增加上述單位的建議。他在接受美聯(lián)社采訪時表示，人們已經(jīng)熟知“毫米”“毫克”等單位中的詞頭“毫”，而新增的4個單位詞頭則能代表目前已測量過的最大和最小數(shù)據(jù)。

“Most people are familiar with prefixes like milli- as in milligram. But these are prefixes for the biggest and smallest levels ever measured,” Dr Richard Brown, head of Metrology at the U.K.’s National Physical Laboratory who proposed the four new prefixes, told The Associated Press.
 

布朗說：“過去30年，數(shù)據(jù)領域的規(guī)模以指數(shù)級別增長，數(shù)據(jù)科學家也意識到，現(xiàn)在沒有合適的詞去形容這個級別的存儲量了。”布朗補充道，新增的單位，方便科學家去描述已經(jīng)知曉的事物。

“In the last 30 years, the datasphere has increased exponentially, and data scientists have realized they will no longer have words to describe the levels of storage,” he explained. Brown said the new terms also make it easier to describe things scientists already know about.
 

據(jù)NPR報道，此前，最大的單位為yotta，即數(shù)字后帶24個零。在描述地球重量時，可以用6000 yottagrams（即yotta詞頭+gram克）?，F(xiàn)在，則可以用6 ronnagrams來表示。太陽的重量可以用 2000 quettagrams來描述，不再需要以前的 2,000,000,000 yottagrams。

Yotta (24 zeroes) was the largest prefix in the metric system before the new additions. Now, the Earth's mass can be said to be about 6 ronnagrams rather than 6,000 yottagrams. The sun can be said to be about 2,000 quettagrams rather than 2,000,000,000 yottagrams.
 

而ronto 和quecto將用于量子科學和粒子物理學。例如電子的質(zhì)量為1 rontogram，而不再用此前最小計量單位的0.001 yotcograms。

The prefixes for small numbers (ronto and quecto) will be useful for quantum science and particle physics. An electron's mass can be said to be about 1 rontogram rather than 0.001 yoctograms (the smallest prefix before the new additions).
 

布朗建議的這4個詞頭的單位，即時生效。這也是1991年以來，國際單位制首次新增內(nèi)容。

The new terms take effect immediately, marking the first time since 1991 that any new additions have been made.
 

他表示，ronna、quetta分別簡寫為R和Q，而ronto和quecto則分別簡寫為r和q。
 

他說，之所以選擇ronna、quetta、ronto和quecto為新增單位詞頭，是因為只有字母r和q尚未被用作單位詞頭，同時這4個單詞發(fā)音聽起來像希臘語發(fā)音，并滿足大單位詞頭以a結(jié)尾、小單位詞頭以o結(jié)尾的慣例。

He explained how the new names were not chosen at random: The first letter of the new prefixes had to be one not used in other prefixes and units.“There were only the letters ‘r’ and ‘q’ that weren’t already taken. Following that, there’s a precedent that they sound similar to Greek letters and that big number prefixes end with an ‘a’ and smaller numbers with an ‘o,’” he added.
 

綜合來源：新華網(wǎng)，NPR，美聯(lián)社