Geocentric model wasn't until Kepler demonstrated a physical observation that could show that the physical sun is directly involved in determining an orbit that a new model was required. The Ptolemaic order of spheres from Earth outward is: Ptolemy did not invent or work out this order, which aligns with the ancient Seven Heavens religious cosmology common to the major Eurasian religious traditions. It also follows the decreasing orbital periods of the moon, sun, planets and stars. Muslim astronomers generally accepted the Ptolemaic system and the geocentric model, but by the 10th century texts appeared regularly whose subject matter was doubts concerning
National Register of Historic Places listings in Central Baltimore city park system are included in the federally designated Baltimore National Heritage Area. National Register of Historic Places listings in Central Baltimore This is a list of National Register of Historic Places properties and districts in downtown Baltimore, Maryland, United States. Many other properties are located in other parts of the city; for these, see National Register of Historic Places listings in Baltimore, Maryland. The locations of the National Register properties and districts listed below (at least for all showing latitude and longitude coordinates below) may be seen in a map by clicking on "Map of all coordinates". Much of