Philosophers of technology have often considered only the tools and processes used and conducted by humans, but natural structures and man-made structures are not always easily discernable from one another. The complexity of a spider web is not matched by many human-made technologies. Beaver dams, beehives, and ant hills are great creations made by non-human animals. Davis Baird has argued that our scientific instruments bear knowledge in important ways, and the idea of technological knowledge bears interestingly on discussions of natural artifacts. Baird thinks his argument for instruments bearing knowledge can be extended, but how far can it be taken? Do "natural" technologies, like spider webs, bear technological knowledge of some sort? This move to consider whether natural artifacts might bear knowledge rubs interestingly against current definitions of technology which include human agency or progression as important. If we find that some natural artifacts seem to bear knowledge in the way Baird describes, technological knowledge would not be the exclusive domain of humans. Our current definitions of technology seem incongruent with our view of knowledge and our knowledge of natural artifacts. The purpose of this paper is to sort out the inconsistencies between current philosophical literature on knowledge and on technology. In sorting out the inconsistencies we find, I recommend a spectrum approach with regard to technology based on the epistemological status of the artifact. Using observations from anthropology and biology, I suggest a scale with regard to technological behavior, tool use, and technology. / Master of Science

Nearfield Acoustical Holography (NAH) is an acoustic field visualization technique that can be used to reconstruct three-dimensional (3-D) acoustic fields by projecting two-dimensional (2-D) data measured on a hologram surface. However, linear NAH algorithms developed and improved by many researchers can result in significant reconstruction errors when they are applied to reconstruct 3-D acoustic fields that are radiated from a high-level noise source and include significant nonlinear components. Here, planar, nonlinear acoustical holography procedures are developed that can be used to reconstruct 3-D, nonlinear acoustic fields radiated from a high-level noise source based on 2-D acoustic pressure data measured on a hologram surface. The first nonlinear acoustic holography procedure is derived for reconstructing steady-state acoustic pressure fields by applying perturbation and renormalization methods to nonlinear, dissipative, pressure-based Westervelt Wave Equation (WWE). The nonlinear acoustic pressure fields radiated from a high-level pulsating sphere and an infinite-size, vibrating panel are used to validate this procedure. Although the WWE-based algorithm is successfully validated by those two numerical simulations, it still has several limitations: (1) Only the fundamental frequency and its second harmonic nonlinear components can be reconstructed; (2) the application of this algorithm is limited to mono-frequency source cases; (3) the effects of bent wave rays caused by transverse particle velocities are not included; (4) only acoustic pressure fields can be reconstructed. In order to address the limitations of the steady-state, WWE-based procedure, a transient, planar, nonlinear acoustic holography algorithm is developed that can be used to reconstruct 3-D nonlinear acoustic pressure and particle velocity fields. This procedure is based on Kuznetsov Wave Equation (KWE) that is directly solved by using temporal and spatial Fourier Transforms. When compared to the WWE-based procedure, the KWE-based procedure can be applied to multi-frequency source cases where each frequency component can contain both linear and nonlinear components. The effects of nonlinear bent wave rays can be also considered by using this algorithm. The KWE-based procedure is validated by conducting an experiment with a compression driver and four numerical simulations. The numerical and experimental results show that holographically-projected acoustic fields match well with directly-calculated and directly-measured fields.