Research - Aelectrosonic Truss 2025, site specific sonic sculpture The Center for Land Use Interpretation, Desert Research Station, Hinkley, CA
Exhibition run: Jan 11 - Mar 15, 2025
Steve Badgett & Deborah Stratman
VIBRATIONAL VARIETY
Audio waves are fundamentally different from electromagnetic waves (such as light or radio). Sound waves are mechanical waves that require a medium to propagate. Electromagnetic waves can travel through a vacuum. Sound waves are longitudinal, vibrating parallel to the direction of travel. Electromagnetic waves are transverse, vibrating perpendicular to the direction of travel. Electromagnetic waves travel at the speed of light (300,000 km/sec). Sound waves travel at 343 m/sec.
VLF waves range in size from 62 to 6 miles, or 3 to 30 kHz. Natural radio occurs at these frequencies, as do the power grid and all electrical devices. Electromagnetic VLF overlaps in frequency with audio waves (20 Hz to 20 kHz), making it possible to hear this part of the electromagnetic spectrum without transposing it.
The ionosphere is, among other things, a conductive cavity surrounding the earth. It is the charged part of the upper atmosphere, ionized by solar radiation. This cavity has natural resonant frequencies called Schumann Resonances. When lightning strikes the ionosphere, it’s like an electric hammer on a giant concentric air gong, generating vibrations sensed by the VLF receiver Aelectrosonic Truss.
The magnetosphere surrounds our planet as a set of nested magnetic fields. It is generated by the geodynamo of Earth’s molten outer core and forms a protective shield that deflects cosmic rays, the solar wind and other radiation harmful to life. When these streams of charged particles collide with our magnetosphere, they deform it, compressing the sun-facing side and elongating the other. The interplay between the supersonic solar wind and the magnetosphere drives space weather, which generates the colorful auroral displays over Earth’s poles and can interfere with satellites, radio communications and electrical grids. The aurora generate radio emissions which themselves can be used to remotely sense the ionosphere and processes that occur there.
