The only thing more ubiquitous than dark matter is plastic and one of the most common plastic materials is polystyrene. Science Synergy recently analyzed one of the infrared spectrum of the thin polystyrene films that are used to calibrate infrared spectrometers. And the analysis reveals evidence for the nature of dark matter in the form of the fundamental particle known as the axion (See Dark Matter Makes Light Bend in the Lab).
Infrared light passing through the polystyrene thin film couples to far-infrared frequency sound waves–known as phonons–within the plastic material. The coupling between the electric field of the sound waves and the magnetic field of the light makes axions provided that the frequency of the light is tuned to the axion resonance. The axion resonance lands at the “beat note” with frequency given by the difference between the natural frequency of the axion and that of the sound wave.
In Fall 2021 Science Synergy Science Chair Noah Bray-Ali calculated the natural frequency of the axion to better than a percent using a novel physical picture of the axion as dark matter with six axions for every photon in the cosmic microwave background (See Making Dark Matter in the Big Bang). The prediction was improved recently by Science Synergy to better than a tenth of a percent precision (See To See the Universe in a Grain of Sand) by analyzing the axion resonances in the Raman visible light scattering spectra of quartz crystal (silicon dioxide), halite (ordinary table salt, sodium chloride), and the mineral witherite (barium carbonate). The value of the axion natural frequency used in the present polystyrene thin film analysis–with 44 parts per million precision–comes from the Science Synergy analysis of 24-year old high-precision near-infrared transmittance spectra of 1.25 millimeter thick samples of polystyrene cut from the clear plastic “jewel boxes” that were used at the time to store compact discs: The high-quality polystyrene infrared spectra were taken by infrared spectroscopists working at the research lab of the major US manufacturer of infrared spectrometers.