The dynamics of life: imaging changing patterns of air surrounding material and biological systems with dynamic interferometry.

233 All material systems are dynamic. From subatomic particles, through atoms, to molecules and biochemicals, processes express and create complex patterns of vibrations (cycles) over time. Living systems, as conventionally defined by biology, express complex dynamic patterns of vibration over large ranges of frequencies. The human body emits dynamic patterns of thermal radiation as well as electromagnetic radiation as part of basic metabolic processes. Cycles with time constants related to blood flow and respiration generate small bursts of thermal energy that create convective air currents we term “microbreezes.” Thermal variations caused by these microbreezes subtly modulate the refractive index of the air around the perimeter of these biologic systems. Subtle changes in the refractive index change the optical path length of rays of light by fractions of a wavelength of light. These subtle optical path length variations can be measured using interferometry (Ciddor, 1996). With the development of high-speed computers and advanced imaging algorithms, it is possible to calculate and display moving images of dynamically changing refractive index variations over time using dynamic interferometry (DI) (Creath and Schwartz, 2004). Because Tucson, AZ, known as Optics Valley is home to the inventors of a novel DI (Millerd, 2003) we were able to explore the potential use of this technology to reveal the dynamics of air patterns surrounding material and biological systems. This technology was originally developed to measure tiny changes in the surface of telescope mirrors during the manufacturing process and later adapted for in situ measurements of air turbulence in telescope domes (Wyant, 2003).