spectrogram

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June 17, 2026

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A spectrogram is a visual representation of a spectrum, often a photograph or diagram. A sound spectrogram specifically records sound, with time on the horizontal axis, frequency on the vertical axis, and intensity shown by varying shades of darkness. This visual record is produced by a spectrograph, an instrument designed to disperse radiation, such as sound waves or electromagnetic radiation, and then map or record the resulting spectrum.123

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comet
Ancient Greece to the 19th century
The first spectrogram (a spectrum recorded on film) was of Comet Tebbutt (C/1881 K1), taken by English astronomer William Huggins on June 24, 1881. Later the same night, an American doctor and amateur astronomer, Henry Draper, took spectra of the same comet. Both men later became professional…
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The first spectrogram (a spectrum recorded on film) was of Comet Tebbutt (C/1881 K1), taken by English astronomer William Huggins on June 24, 1881. Later the same night, an American doctor and amateur astronomer, Henry Draper, took spectra of the same comet. Both men later became professional…
Read More