The spectroscopic data will be useful in modelling other systems that contain extremely hot water molecules, such as forest fires and rocket plumes. Spectral analysis captures the characteristic spectra, or wavelength patterns, emitted or absorbed by molecules. Starting with a mathematical model that is progressively improved through perturbation theory doesn't work for hot water. Instead, the team went directly to theory and used the calculated interaction energies of the atoms of water. By using sophisticated variational calculations of energy levels, the researchers predicted the position of transitions that give rise to absorption lines.
Spectroscopy is the study of the interaction of light and matter.