Spectroscopy is the science of studying light after it has been split into its separate colours. It is a field of study, not a machine — the dictionary line calling it 'an instrument' has slipped; the instrument is a spectroscope. Here is the idea in plain words.

Spectroscopy is the science of studying lightspectroscopy是研究光線的一門科學 after it has been split into its separate colours在光被分解成各自的顏色之後 It is a field of study, not a machine它是一門學科，不是一台機器 — the dictionary line calling it 'an instrument' has slipped字典裡把它說成「一種儀器」的那行寫錯了 the instrument is a spectroscope那個儀器其實叫做spectroscope Here is the idea in plain words用簡單的話來說明這個概念

When a substance burns, glows, or has light shone through it, it does something very particular with the colours: it gives out certain ones and swallows certain others. Every element behaves in its own way, so the pattern of colours works like a fingerprint. Spectroscopy is the practice of reading those fingerprints.

When a substance burns, glows, or has light shone through it當一種物質燃燒、發光，或是被光照射穿過時 it does something very particular with the colours它會對顏色做出很特別的事 it gives out certain ones and swallows certain others它會放出某些顏色，又吸收掉某些顏色 Every element behaves in its own way每一種元素的表現方式都不一樣 so the pattern of colours works like a fingerprint所以那個顏色的模式就像指紋一樣 Spectroscopy is the practice of reading those fingerprintsspectroscopy就是解讀這些指紋的這門學問

It is one of the most powerful tools in science, and its reach is surprising.

It is one of the most powerful tools in science它是科學裡最強大的工具之一 and its reach is surprising而它應用的範圍廣得驚人

Astronomers use it to say what a star is made of, and how fast it is moving away from us, without ever going near it. Chemists use it to identify unknown substances. Doctors use it in scanners. Police labs use it on evidence.

Astronomers use it to say what a star is made of天文學家用它來判斷一顆星星是由什麼組成的 and how fast it is moving away from us還有它離我們遠去的速度有多快 without ever going near it完全不用靠近它 Chemists use it to identify unknown substances化學家用它來辨認未知的物質 Doctors use it in scanners醫生把它用在掃描儀器上 Police labs use it on evidence警方的實驗室用它來分析證物

You will meet the word in physics and chemistry lessons and in any serious article about space.

You will meet the word in physics and chemistry lessons你會在物理和化學課裡遇到這個字 and in any serious article about space也會在任何講太空的正經文章裡看到它

It is a mass noun, so no 'a' and no plural: say 'spectroscopy is used to…', not 'a spectroscopy'. There are many named types — mass spectroscopy, infrared spectroscopy — and those phrases are how you will usually see it.

It is a mass noun它是一個不可數名詞 so no 'a' and no plural所以不能加'a'也沒有複數 say 'spectroscopy is used to…'要說'spectroscopy is used to…' not 'a spectroscopy'不能說'a spectroscopy' There are many named types還有很多有專門名稱的種類 — mass spectroscopy, infrared spectroscopy —像是mass spectroscopy（質譜學）、infrared spectroscopy（紅外光譜學） and those phrases are how you will usually see it而你平常看到的通常就是這樣的說法