Group Theory and Symmetry, Part I: Symmetry Elements

December 1st 2009Group theory is the field of mathematics that includes, among other things, the treatment of symmetry. Well, it turns out that molecules have symmetry, so group theoretical principles can be applied to molecules. Because spectroscopy uses light to probe the properties of molecules, it might not be surprising that group theory has some application to spectroscopy. Here, we start a multipart discussion of symmetry and group theory.

Spectroscopy Is Applied Quantum Mechanics, Part IV: Ideal Systems

June 1st 2008In Parts I-III of this series, columnist David W. Ball recounted the failings of classical mechanics, the quantum hypothesis, and the rise of a new theory called quantum mechanics. In this installment, he discusses the ideal systems whose wavefunctions can be determined exactly from the Schr?dinger equation.

Spectroscopy Is Applied Quantum Mechanics, Part II: The Quantum Revolution

January 1st 2008In part I of this series, columnist David Ball laid the groundwork for why the scientific understanding of nature in the late 19th century was found wanting: it could not explain a variety of phenomena that scientists were examining. (One of these phenomena was spectroscopy itself!) In this installment, he reviews the paradigm shifts in science that preceded the development of the currently accepted theories of the nature of matter. It all starts with the nature of light.

Atomic Clocks: An Application of Spectroscopy

January 1st 2007In the previous installment of this column, the author discussed clocks as the first scientific instrument. What do clocks have to do with spectroscopy? Actually, the world's most accurate clocks, atomic clocks, are based upon a spectroscopic transition of cesium or other elements, making spectroscopy a fundamental tool in our measurements of the natural universe.

The Original Scientific Instrument

December 1st 2006After due consideration in his copious free time, columnist David Ball comes to the conclusion that the world's original scientific instrument was the clock. This might provoke a question: What does it have to do with spectroscopy? The answer might surprise readers.

The Baseline: The Solar Spectrum

June 1st 2005Spectroscopists separate light from the sun into spectra and look for the presence or absence of particular lines that give hints regarding its chemical composition. The same method can be applied to studying the composition of other matter in the universe.