Related papers: Lines, dots and spirals on Peruvian land
America's first urban centres were allegedly located at the Supe Valley sites in Peru. After investigating the location and the orientation of the main built structures, we show that it is not only the presence of the River Supe that…
Why is it that we can recognize object identity and 3D shape from line drawings, even though they do not exist in the natural world? This paper hypothesizes that the human visual system perceives line drawings as if they were approximately…
An efficient computer algorithm is described for the perspective drawing of a wide class of surfaces. The class includes surfaces corresponding lo single-valued, continuous functions which are defined over rectangular domains. The algorithm…
An ancient solar observatory is composed by thirteen towers lined on a hill of a coastal desert of Peru. This is the Chankillo observatory. Here we discuss it, showing some simulations of the local sun direction. An analysis of the…
Stellar occultations provide a powerful tool to explore objects of the outer solar system. The Gaia mission now provides milli-arcsec accuracy on the predictions of these events and makes possible observations that were previously…
The universe region obscured by the Milky Way is very large and only future blind large HI redshift, and targeted peculiar surveys on the outer borders will determine how much mass is hidden there. Meanwhile, we apply for the first time two…
HI observations in the 21cm line have been a principal tool for investigating the large-scale structure of the Milky Way. This review considers what was learned in the first decade after the discovery of the 21cm line, and how that…
Summer 2015 marked the 100th anniversary of the excavation by J.W. Fewkes of the Sun Temple in Mesa Verde National Park, Colorado, an ancient complex prominently located atop a mesa, constructed by the ancestral Pueblo peoples approximately…
The two-dimensional surface of a bi-axial ellipsoid is characterized by the lengths of its major and minor axes. Longitude and latitude span an angular coordinate system across. We consider the egg-shaped surface of constant altitude above…
Mysterious duality is a relationship, described by Vafa in 2000, between $\frac12$-BPS branes in Type II supergravity in dimension $D=d+2$ and rational curves on del Pezzo surfaces of degree $d$. We show that both sides of this…
We consider an infinite graph with the vertex set $\mathbb{Z}^2$ and edges connecting the vertices iff the Euclidean distance between the respective points is an integer, and the points do not lie on the same horizontal or vertical.…
All human societies present unique narratives that shape their customs and beliefs. Despite cultural differences, some symbolic elements (e.g., heroes and tricksters) are common across many cultures. Here, we reconcile these seemingly…
A parallelogram is conformally inscribed in four lines in the plane if it is inscribed in a scaled copy of the configuration of four lines. We describe the geometry of the three-dimensional Euclidean space whose points are the…
A man-made texture on the desert soil of a county of the Western China is visible in satellite images, more than 8 kilometers long and 50 meters wide. This seems to be the result of a detailed geophysical survey of the region that led to…
The distribution of galaxies up to a distance of 200 Mpc (650 million light-years) is flat and shows a structure like a shell roughly centered on the Local Supercluster (Virgo cluster). This result clearly confirms the existence of the…
We have produced a new conformal map of the universe illustrating recent discoveries, ranging from Kuiper belt objects in the Solar system, to the galaxies and quasars from the Sloan Digital Sky Survey. This map projection, based on the…
Spine spaces can be considered as fragments of a projective Grassmann space. We prove that the structure of lines together with binary coplanarity relation, as well as with binary relation of being in one pencil of lines, is a sufficient…
A graph is a mathematical object consisting of a set of vertices and a set of edges connecting vertices. Graphs can be drawn on paper in various ways, but until recently all published methods of drawing graphs have had undesirable…
The aim of this paper is in stimulating the use of satellite imagery, in particular the free service of Google Maps, to investigate the distribution of the agricultural technique of terraced hills in Andean countries, near Titicaca Lake. In…
The nature of the spiral structure of the Milky Way has long been debated. Only in the last decade have astronomers been able to accurately measure distances to a substantial number of high-mass star-forming regions, the classic tracers of…