|A more dramatic example of visible flame spectroscopy, by Arthur Jan |
Fijalkowski, CC-BY-SA-3.0. SOURCE.
In the physics sense, spectra (the plural of spectrum) are energy emitted in the form of different wavelengths, such as electromagnetic radiation, which includes gamma rays, x-rays, ultraviolet, visible light, infrared, microwaves, and radio waves. Spectroscopy is used to determine the composition and the movement of matter, based on how it reacts to radiation.
Part of spectroscopy focuses on visible light and its colors, though there is also--and to name just a few of the many different kinds of spectroscopy--atomic absorption spectroscopy (the study of how energy is absorbed using radiation), electron paramagnetic spectroscopy (which uses microwaves), electron spectroscopy (measures changes in electron energy levels), Fourier transform spectroscopy (matter is bombarded with radiation and the results analyzed with mathematics), gamma-ray spectroscopy, infrared spectroscopy, mass spectrometry (generates ions that interact with the matter in question), Mossbauer spectroscopy (used in mineralogy to detect iron), Raman spectroscopy (uses the scattering of light to find the vibration and rotation of molecules), and x-ray spectroscopy.
For more detail about how spectroscopy actually works, let's take the example of light. Light spectroscopy examines continuous and discrete spectra: A continuous spectrum includes a range of colors with few interruptions along the observed wavelengths, while a discrete spectrum has dark-light contrast between wavelengths.
Specific elements can be determined using spectroscopy because when an atom absorbs energy its electrons move into a higher orbit, and when the electrons fall back to a lower orbit, energy is released in the form of a certain wavelength of radiation. With discrete spectra, brighter colors are emission spectra and darker spikes are absorption spectra, and these fluctuations are characteristic to certain atoms and molecules. This use of spectroscopy is particularly important in astronomy, and the matter, temperature, density, and motion of objects in space can be discerned from those observed changes.
|An example of magnetic resonance spectroscopy (MRS). |
© Nevit Dilmen, CC-BY-SA-3.0. SOURCE.
Joseph P. Hornak
Joseph Hornak is a Professor of Chemistry, Materials Science and Engineering, and Imaging Science at the, and the Director of the Magnetic Resonance Laboratory at the Rochester Institute of Technology (RIT), as well as an Adjunct Associate Professor of Radiology at the University of Rochester. He graduated with a Ph.D. in Chemistry from Notre Dame University and is a Fellow of the American Chemical Society, International Society of Magnetic Resonance, and the Environmental and Engineering Geophysical Society.
His research at RIT involves magnetic resonance imaging (MRI) and magnetic resonance spectroscopy.
Think you'd ever want to be a spectroscopist? (I actually found job listings, which I've never come across for any other scientific field I researched.)
-----The Golden Eagle