Eddie Moler is shown here with a Fourier transform spectrometer that he helped design and build. He uses instruments like this for basic research. With a spectrometer, Eddie is able to identify the elements in a sample and their chemical states. The samples are stored inside a stainless steel chamber evacuated of gas (a vacuum chamber). This prevents exposure to air and other gases that would cause a chemical reaction on the surface and change the sample. Thus, the vacuum chamber makes a "perfectly clean sample."

Inside the spectrometer, light enters on one side then gets split into two beams. The two beams travel along separate pairs of accurately aligned mirrors then converge at the other end. One of the two beams travels farther than the other, and the experimenter can change how much farther it goes by moving the mirrors. The recombined beams are projected out into the sample chamber, where the measuring takes place. The x-rays "look" at gaseous atoms and are used to measure the energies of electrons in the atoms. With this, scientists can understand the complicated interactions that are at the heart of chemical reactions.