What is spectroscopy?
Spectroscopy analyzes light by wavelength to study a source and its interaction with matter.
How it works and what the evidence shows
Core idea A prism or grating separates light by wavelength. Atoms and molecules absorb or emit at characteristic wavelengths, producing lines linked to physical conditions. Evidence and research Astronomers compare stellar and gas spectra with laboratory measurements. Line positions and strengths reveal composition, temperature and some motion, provided instruments are calibrated.
Uses and limitations
Why it matters Laboratories use spectroscopy for identification and measurement. Visible, infrared and radio bands can reveal complementary aspects of one object. Common misunderstandings A single line cannot establish a complete composition or prove life. Overlapping lines, temperature, density and instrument effects must be considered together.