Surveying the solar system by measuring angles and times: from the solar density to the gravitational constant
نویسنده
چکیده
A surprisingly large amount of information on our solar system can be gained from simple measurements of the apparent angular diameters of the sun and the moon. This information includes the average density of the sun, the distance between earth and moon, the radius of the moon, and the gravitational constant. In this note it is described how these and other quantities can be obtained by simple earthbound measurements of angles and times only, without using any explicit information on distances between celestial bodies. The pedagogical and historical aspects of these results are also discussed briefly.
منابع مشابه
Evaluation of solar-chimney power plants with multiple-angle collectors
Solar chimney power plants are plants based on solar thermal power including three parts of collector, chimney and turbine, which is able to produce electrical energy. One of the effective parameters in increasing the power production is the collector angles versus horizon. In the present study, a numerical analysis of a solar chimney power plant for different angles of the collector (divergent...
متن کاملStudy of Solar Magnetic and Gravitational Energies Through the Virial Theorem
Virial theorem is important for understanding stellar structures. It produces an interesting connection between magnetic and gravitational energies. Using the general form of the virial theorem including the magnetic field (toroidal magnetic field), we may explain the solar dynamo model in relation to variations of the magnetic and gravitational energies. We emphasize the role of the gravitatio...
متن کاملAnalyzing the angles of building orientation for solar energy use (Case study: Tehran city)
Introduction and Background: One of the approaches to reduce fossil fuel consumption and their pollution in cities, is to pay attention to the climatic conditions and ecosystems of the region and to use renewable energy in architecture and the design of buildings; This subject in the case for Tehran metropolis is more important, due to the high concentration of population and the activity and, ...
متن کاملOptimal Angle for Solar Panels to Receive Maximum Radiation: Case of Mashhad City
The solar arrays are one of the most promising renewable energy technologies for providing energy needs . in buildings. For installed solar panels on building roofs, knowing the optimal inclination angle is important in order to obtain the maximum annual or seasonal energy. In fact, the changes in slope angle affect the amount of solar radiation that reaches the surface of the panel. In this s...
متن کاملEffect of Solar Angles on Incident Energy of the Flat Collectors
In this paper the daily, monthly, seasonally, and yearly optimum slope angles of solar collectors are determined for areas in Iran and new models are developed to calculate the monthly, seasonally, and yearly optimum slope angles for latitudes of to north. To achieve this purpose, the slope and surface azimuth angles of solar collectors for receiving maximum solar radiation were determined ...
متن کامل