Related papers: Specular Reflection from the Great Pyramid at Giza
Recently, the Kepler Space Telescope has detected several planets in orbit around a close binary star system. These so-called circumbinary planets will experience non-trivial spatial and temporal distributions of radiative flux on their…
We reconsider the description of a solar eclipse in the Coptic ostracon in the Egyptian museum, Turin, confirming its identification with the solar eclipse of 10 march 601. This provides one of very few fixed dates in Coptic chronology. We…
The Picture Rocks Sun Dagger is a spiral petroglyph on a hillside northwest of Tucson that shows sun dagger events at both the summer solstice and the equinoxes. On each of these dates, a wedge-shaped sunbeam with opening angles…
We have made a high resolution study of the specularity of the atomic reflection from an evanescent wave mirror using velocity selective Raman transitions. We have observed a double structure in the velocity distribution after reflection: a…
We express the position of the Sun in the sky as a function of time and the observer's geographic coordinates. Our method is based on applying rotation matrices to vectors describing points on the celestial sphere. We also derive direct…
Variations and spatial distributions of bright and dark material on dwarf planet Ceres play a key role in understanding the processes that have led to its present surface composition. We define limits for bright and dark material in order…
An experiment for the speckle reconstruction of solar features was developed for observing the partial eclipse of the sun as viewed from Bangalore on October 24, 1995. No data could be obtained because of cloudy sky but the experimental…
Specular reflection is known to play an important role in many fields of scattering applications, e.g., in remote sensing, computer graphics, optimization of visual appearance of industrial products. Usually it can be assumed that the…
A re-investigation of the parapegma of Euktemon (5th century BC, Athens), based on the assumption that some star observations may in fact have been calculated rather than directly observed. The calculation follows Pliny, Natural History…
The analysis of databases of photographic images of the Sun (obtained in region of soft x-ray) by means of a method of multilevel dynamical contrasting, has shown presence of skeletal structures of the Sun as outside (chromo-sphere flashes…
The displacement of star images by atmospheric refraction observed by an Earth-bound telescope is dominated by a familiar term proportional to the product of the tangent of the zenith angle by the refractivity at the ground. The manuscript…
Rings around giant exoplanets (hereafter 'exorings') are still a missing planetary phenomenon among the vast number of discovered planets. Despite the fact there exist a large number of methods for identifying and characterizing these…
Sunspots are prominent manifestations of the solar cycle and provide key constraints for understanding its operation. Also, knowing internal structure of sunspots allows us to gain insights on the energy transport in strong magnetic fields…
The scattering of light dark matter off thermal electrons inside the Sun produces a "fast" sub-component of the dark matter flux that may be detectable in underground experiments. We update and extend previous work by analyzing the…
Magnetic reconnection in the quiet Sun is a phenomenon that is consistently observed, and it has recently become feasible to simulate via 3D numerical models of realistically stratified and convection-driven reconnection. We aim to…
High altitude meteors become luminous at altitudes above $\sim$130 km, where the standard ablation theory of meteor light production is not applicable. The physical mechanism responsible for their glow has not been known. We present a model…
The scattering of dark matter particles within the Sun's hot plasma can lead to acceleration of dark matter, producing a high-energy solar-reflected DM flux detectable in ground-based experiments. In the vector portal model, interactions…
Among surprising results of NASA's Dawn spacecraft mission at dwarf planet Ceres are enigmatic bright spots inside Occator crater and a lone tall pyramid mountain. Here we explain the appearance of such spots, weird mountains, and…
Given a light source, a spherical reflector, and an observer, where on the surface of the sphere will the light be directly reflected to the observer, i.e. where is the the specular point? This is known as the Alhazen-Ptolemy problem, and…
Astronomy arises very early in a civilization and evolves as the civilization advances. It is therefore reasonable to assume that a vibrant knowledge of astronomy would have been a feature of a civilization the size of the Harappan…