Reversals in Wartime: Alcuin and Charlemagne discuss Retrograde Motion

The apparent retrograde motion of the planets was a puzzle for astronomers from the ancient world to the final establishment of heliocentric cosmology in the early modern period, but enjoyed an especially rich discussion in the Carolingian Renaissance. We explore the first stirrings of an eighth-century response to this epistemological challenge in a remarkable series of letters between Alcuin of York and Charlemagne, sent while the latter was on campaign against the Saxons in 798 CE. Their exchange constitutes the longest discussion of the phenomenon of Mars' retrograde motion in the West up to that date. Our consideration of the relevant letters explores Alcuin's ability to marshal diverse and complex explanatory narratives and observational traditions around the problem of the retrograde motion of the planet Mars, even as he was unable to fully reconcile them. Attention to his ultimately unsuccessful (and at times contradictory) attempts at explanation suggest that he relied on knowledge from sources beyond those previously recognized, which we identify. Charlemagne's curiosity about the matter can be located in the much longer context of an ancient tradition of imperial and royal concern with heavenly phenomena; at the same time, the exchange with Alcuin heralds the ninth-century expansion of astronomy away from the computists' preoccupation with the solar and lunar calendrical data required to calculate the date of Easter and towards a more wide-ranging curiosity about observed planetary motion irrelevant to Easter dating and computistical calculations. Alcuin's functional, if not geometrical, assumption of the centrality of the sun in his explanation merits a further examination of the more general sense in which lost ancient heliocentric ideas sustained early medieval echoes.

The Communication Infrastructures of Living Systems and the Universe: Analysis from the Perspective of Antenna Theory

It is still unknown how molecules coordinate their activity and operate at high speeds in the crowded environment of a cell. The study focuses on the geometry of biomolecules, assuming B-DNA, α-helix, β-strand, water molecules, and chemical bonds, including hydrogen bonds, as various types of antennas. The analysis demonstrates that living systems have highly sophisticated wireless and wired communication infrastructures for regulating and coordinating molecular activities, revealing why water is essential for molecular dynamics and indicating how we evolved. The study also includes a few equations linking antenna fields with Einstein’s general relativity, Kepler’s law of planetary motion, and Newton’s law of gravitation, which divides the gravitational field into antenna field zones and clarifies many astronomical facts. The findings, furthermore, suggest that the gravitational field is the antenna field of astronomical objects; and that nature's antennas, such as molecules and astronomical objects, communicate via gravitational waves. We hope that the study, which uses a classical approach to explain the facts of living systems and the Universe, will find applications in biology, astronomy, communication engineering, and other areas of science.

The Communication Infrastructures of Living Systems and the Universe: Analysis from the Perspective of Antenna Theory

It is still unknown how molecules coordinate their activity and operate at high speeds in the crowded environment of a cell. The study focuses on the geometry of biomolecules, assuming B-DNA, α-helix, β-strand, water molecules, and chemical bonds, including hydrogen bonds, as various types of antennas. The analysis demonstrates that living systems have highly sophisticated wireless and wired communication infrastructures for regulating and coordinating molecular activities, revealing why water is essential for molecular dynamics and indicating how we evolved. The study also includes a few equations linking antenna fields with Einstein’s general relativity, Kepler’s law of planetary motion, and Newton’s law of gravitation, which divides the gravitational field into antenna field zones and clarifies many astronomical facts. The findings, furthermore, suggest that the gravitational field is the antenna field of astronomical objects; and that nature's antennas, such as molecules and astronomical objects, communicate via gravitational waves. We hope that the study, which uses a classical approach to explain the facts of living systems and the Universe, will find applications in biology, astronomy, communication engineering, and other areas of science.

KEPLER – NEWTON – LEIBNIZ – HEGEL

Kepler’s Laws of planetary motion (following the Copernican revolution in cosmology), according to Leibniz and his follower Hegel, for the first-time in history discovered the keys to what Hegel called the absolute mechanics mediated by dialectical laws, which drives the celestial bodies, in opposition to finite mechanics in terrestrial Nature developed by mathematical and empirical sciences, but that are of very limited scope. Newton wrongly extended and imposed finite mechanics on the absolute mechanics of the cosmic bodies in the form of his Law of one-sided Universal Gravitational Attraction, by distorting and misrepresenting Kepler’s profound laws and in opposition to Leibniz’s more appropriate “Radial Planetary Orbital Equation”. The still-prevailing error by Newton (notwithstanding his well known manipulation of science for selfish ends), not only shows the limitation of mathematical idealism and prejudice driven modern cosmology in the form of Einstein’s theories of relativity; but also, have made gaining positive knowledge of the cosmos an impossibility and has impaired social/historical development of humanity by reinforcing decadent ruling ideas. Hegel’s Naturphilosophie is not only a protest against the misrepresentation of Kepler’s Laws in particular; his Enzyklopädie der Philosophischem Wissenschaften is the negation and the direct rebuttal of Newtonian physics and Philosophiæ Naturalis Principia Mathematica, in general. Modern natural science ignores Leibniz and Hegel at its own peril! Kepler’s phenomenological laws of planetary motion and the dialectical insights of Leibnitz and Hegel opens the way for gaining positive knowledge of the dynamics, structure and the evolution of the cosmic bodies and other cosmic phenomena; without invoking mysteries and dark/black cosmic entities, which has been the pabulum of official astrophysics and cosmology so far.

The use of physics pocketbook based on augmented reality on planetary motion to improve students' learning achievement

This article is one of the results of the augmented reality (AR)-based pocketbook development on the planetary motion which focuses on student learning achievement. The study used the ADDIE model: "Analysis-Design-Development-Implementation-Evaluation". In the Spring Semester 2020, researchers took these steps in producing an AR-based pocketbook on planetary motion materials. The trial carried out on 30 students at a public high school in Surabaya, Indonesia. Evaluation parameters included the quality of AR-based pocketbook, students' learning achievement, and research outputs. The results showed that: (1) the process of developing an AR-based pocketbook on planetary motion fulfilled the product quality criteria: validity, practicality, and effectiveness; (2) students' learning achievement increase as seen from the results of the pretest-posttest scores with the average Gain score was 0.63 in the moderate category; (3) through the development of an AR-based pocketbook, it resulted in some articles in journals and pocketbook media based on Augmented reality. Planetary motion in physics learning is an abstract concept and requires high reasoning. Therefore, the recommendation of this study is the use of AR as a media for learning in other abstract physics concepts.

Optimal Trajectory Synthesis for Spacecraft Asteroid Rendezvous

Several researchers are considering the plausibility of being able to rapidly launch a mission to an asteroid, which would fly in close proximity of the asteroid to deliver an impulse in a particular direction so as to deflect the asteroid from its current orbit. Planetary motion, in general, and the motion of asteroids, in particular, are subject to planetary influences that are characterised by a kind of natural symmetry, which results in an asteroid orbiting in a stable and periodic or almost periodic orbit exhibiting a number of natural orbital symmetries. Tracking and following an asteroid, in close proximity, is the subject of this paper. In this paper, the problem of synthesizing an optimal trajectory to a NEO such as an asteroid is considered. A particular strategy involving the optimization of a co-planar trajectory segment that permits the satellite to approach and fly alongside the asteroid is chosen. Two different state space representations of the Hill–Clohessy–Wiltshire (HCW) linearized equations of relative motion are used to obtain optimal trajectories for a spacecraft approaching an asteroid. It is shown that by using a state space representation of HCW equations where the secular states are explicitly represented, the optimal trajectories are not only synthesized rapidly but also result in lower magnitudes of control inputs which must be applied continuously over extended periods of time. Thus, the solutions obtained are particularly suitable for low thrust control of the satellites orbit which can be realized by electric thrusters.

Shaken and Stirred: When Bond Meets Suess–de Vries and Gnevyshev–Ohl

We argue that the most prominent temporal features of the solar dynamo, in particular the Hale cycle, the Suess–de Vries cycle (associated with variations of the Gnevyshev–Ohl rule), Gleissberg-type cycles, and grand minima can all be explained by combined synchronization with the 11.07-year periodic tidal forcing of the Venus–Earth–Jupiter system and the (mainly) 19.86-year periodic motion of the Sun around the barycenter of the solar system. We present model simulations where grand minima, and clusters thereof, emerge as intermittent and non-periodic events on millennial time scales, very similar to the series of Bond events which were observed throughout the Holocene and the last glacial period. If confirmed, such an intermittent transition to chaos would prevent any long-term prediction of solar activity, notwithstanding the fact that the shorter-term Hale and Suess–de Vries cycles are clocked by planetary motion.

Controlling Film Thickness Distribution by Magnetron Sputtering with Rotation and Revolution

The laterally graded multilayer collimator is a vital part of a high-precision diffractometer. It is applied as condensing reflectors to convert divergent X-rays from laboratory X-ray sources into a parallel beam. The thickness of the multilayer film varies with the angle of incidence to guarantee every position on the mirror satisfies the Bragg reflection. In principle, the accuracy of the parameters of the sputtering conditions is essential for achieving a reliable result. In this paper, we proposed a precise method for the fabrication of the laterally graded multilayer based on a planetary motion magnetron sputtering system for film thickness control. This method uses the fast and slow particle model to obtain the particle transport process, and then combines it with the planetary motion magnetron sputtering system to establish the film thickness distribution model. Moreover, the parameters of the sputtering conditions in the model are derived from experimental inversion to improve accuracy. The revolution and rotation of the substrate holder during the final deposition process are achieved by the speed curve calculated according to the model. Measurement results from the X-ray reflection test (XRR) show that the thickness error of the laterally graded multilayer film, coated on a parabolic cylinder Si substrate, is less than 1%, demonstrating the effectiveness of the optimized method for obtaining accurate film thickness distribution.