The culture of flat earth and its consequences

Tracing some elements of the history of science, such as the tradition of map-making beginning in ancient times, this article aims to link together some factors that have led to the contemporary phenomenon of flat earth belief. Springing from a political fringe culture steeped in a ‘will-to-mistrust’, flat earth belief has gained huge popularity in recent years. The total rejection of science in favour of opinion is today a feature of the discursive landscape, and nowhere it is more poignant than in flat earth belief. Furthermore, it leaks from a mistrust of science to mistrust of culture itself. Ultimately it falls to the agency of recent communication technologies, that is, the internet, where this culture is able to gain traction in popular discourse. Through a very simple geometrical argument needing no equipment, I demonstrate that the earth must be spherical (or near-so), and this ultimately points to the technocratic culture today that has paradoxically led to this unpredicted phenomenon. Moreover it is a dangerous trend, and this piece aims to highlight why this is so.

Geometry Dependent Resistivity in Single-walled Carbon Nanotube Films Patterned Down to Submicron Dimensions

ABSTRACTWe demonstrate patterning of SWNT films down to 200 nm lateral dimensions using e-beam lithography and reactive ion etching with good selectivity and directionality and then we fabricate standard four-point-probe structures to characterize the resistivity of these films as a function of device geometry. The resistivity is found to be independent of device length for a given width and thickness, while increasing over three orders of magnitude compared to bulk films, as the width and the thickness of the films shrink. In particular, the resistivity of SWNT films starts to increase with decreasing device width below 20 μm, exhibiting an inverse power law dependence on device width at sub-micron dimensions. We explain this behavior by a purely geometrical argument. Although the “top-down” patterning of nanotube films allows for their use in sub-micron device structures and perhaps their integration into standard silicon fabrication technology, the resistivity scaling is an important effect that needs to be taken into account when fabricating small devices in which nanotube film transport characteristics play a vital role.

Imaging salt with turning seismic waves

Turning seismic waves, which first travel downward and then upward before (and after) reflection, have been recorded in a 3-D seismic survey conducted over an overhanging salt dome. Careful processing of these turning waves enables the imaging of the underside of the salt dome and of intrusions of salt into vertical faults radiating from the dome. When seismic wave velocity increases with depth, waves that initially travel downward are reflected and may turn so as to travel upward before reflection. A simple geometrical argument suggests that these turning waves are likely to exhibit abnormal moveout in common‐midpoint (CMP) gathers, in that reflection time decreases with increasing source‐receiver offset. This abnormal moveout and the attenuation of turning waves by most migration methods suggest that conventional seismic processing does not properly image turning waves. The most important step in imaging turning waves, assuming that they have been recorded, is the migration process. Simple and inexpensive modifications to the conventional phase‐shift migration method enable turning waves to be imaged for little additional computational cost. The examples provided in this paper suggest that these and other such modifications to conventional processing should be used routinely when imaging salt domes.

Mechanistically based, allometric models to predict tree diameter and height in even-aged monoculture of Eucalyptusregnans F. Muell.

A randomly selected sample of 22 trees was felled in a stand in a 20-year-old monoculture of Eucalyptusregnans F. Muell. in southern Tasmania. One-half of the trees were from a section of the stand that had been heavily thinned 10 years previously, and the remainder were from the unthinned section. The trees were sectioned and the fresh weights of their stems (including bark) and crowns (leaves plus branches) determined. By combining a geometrical argument about the shape of tree stems with a structural argument about their vertical stability, allometric relationships were established relating tree diameter at breast height or tree height to total aboveground weight and the ratio of crown to stem weight. These relationships were found to hold in both the thinned and unthinned sections of the experiment. When combined with a model to predict biomass of individual trees, these models can be used to predict diameter or height of individual trees in E. regnans monoculture.

Epitaxy in the Presence of Very Large Misfit: High Resolution TEM Study of Al/Si, Ag/Si, Al/CaF2/Si and Ag/CaF2/Si

ABSTRACTWe summarize high resolution transmission electron microscopy studies of interfaces with 33% misfit. We explain the existence of epitaxial interfaces for this systems by a geometrical argument similar to the 0-lattice models used to study high angle grain boundaries. Differences between systems very similar in structures are explained. We use the thus found epitaxial interfaces to build multilayered structures of the type metal/insulator/semiconductor.

Lower Bounds for the Ramsey Numbers

A lower bound for a family of Ramsey numbers is derived using a geometrical argument.