exa
exa — 字首
1. added to the front of a unit of measurement (such as the metre, gram, or watt) t
艾可薩
國際單位制詞頭，10^18倍
added to the front of a unit of measurement (such as the metre, gram, or watt) to mean 10^18 (one quintillion) times that unit — for example, an exametre is one quintillion metres, a distance used in astronomy for objects far beyond our solar system.
Evelyn learnt in class that one exametre equals a quintillion metres, or about 110 light-years.
Evelyn 在天文課上學到，一艾可薩公尺等於一百京公尺，大約是 110 光年的距離。
exa- + metre → measurement of astronomical distance
The Sun releases roughly 400 exawatts of energy each second into the surrounding solar system.
太陽每秒向周圍的太陽系釋放出約 400 艾可薩瓦特的能量。
exa- + watt → stellar-scale power unit
Geologists at the site estimated the upper mantle at over 800 exagrams of rock.
鑽探現場的地質學家估計，地函上層的質量超過 800 艾可薩公克的固體岩石。
Nila checked the SI prefix table: exa- comes after peta- and means a thousand-fold increase.
Nila 查了國際單位制詞頭表：艾可薩排在拍它之後，代表千倍的增量。
Ada's physics report calculated a pulsar's frequency at 30 exahertz, beyond any radio wave humans can detect.
Ada 的物理報告計算出一顆脈衝星的頻率高達 30 艾可薩赫茲，超出人類可偵測的無線電波範圍。
- yocto-
the SI prefix for 10^-24, representing an unimaginably tiny scale at the opposite extreme from exa-
文法句型
exa- + [unit of measurement] → noun (e.g. exametre, exagram, exawatt)
用法筆記
The prefix exa- appears almost exclusively in specialist scientific writing (astronomy, geology, particle physics). In everyday conversation, people do not use exametres or exagrams. It forms nouns only — never adjectives.
常見錯誤
❗ 'The lake holds ten exagrams of water.' ✅ 'The Pacific Ocean holds about 700 exagrams of water.' — exa- quantities are astronomically large; they almost never apply to everyday objects or locations.
2. used with terms for data storage or computing speed (byte, flop, bit) to mean on
百萬兆
電腦資料容量或運算速度
used with terms for data storage or computing speed (byte, flop, bit) to mean one quintillion (10^18) units — for example, an exabyte is a quintillion bytes of data, roughly the amount of internet traffic the world sends each month.
Walid backed up the company's servers, which held nearly two exabytes of customer data.
Walid 備份了公司的伺服器，其中儲存了近兩百萬兆位元組的客戶記錄和交易資料。
exa- + byte → large data-storage unit
Sumin's team built a supercomputer that runs at one exaflop for typhoon weather modelling.
Sumin 的團隊打造了一臺可執行一百萬兆次運算的超級電腦，用於颱風氣象模擬。
exa- + flop → computing speed unit
Global video streaming alone now generates over three exabytes of internet traffic every single month.
全球的線上影音串流服務每個月就產生超過三百萬兆位元組的網路流量。
Pedro read that the Large Hadron Collider produces 30 exabytes of data each year for physicists to study.
Pedro 讀到大型強子對撞機每年產生 30 百萬兆位元組的數據供物理學家研究。
Elena's lab stores genome sequences in a database that will reach one exabyte by next spring.
Elena 的研究實驗室儲存基因組序列的資料庫，將在明年春天突破一百萬兆位元組。
文法句型
exa- + [computing noun] → noun (e.g. exabyte, exaflop, exabit)
用法筆記
The computing sense is more common than the scientific one in everyday media, especially in technology news about data centres and supercomputers. Note that exabyte can refer to either 10^18 bytes (decimal) or 2^60 bytes (binary), depending on the operating system or standard being used.
常見錯誤
❗ 'My new laptop has an exabyte hard drive.' ✅ 'The cloud data centre stores over two exabytes of backup files.' — exa-scale storage exists only in massive data centres and scientific facilities, not in personal devices.