Geocentric model coelestium" ("On the Revolutions of the Heavenly Spheres"), which posited that the Earth and the other planets instead revolved around the Sun. The geocentric system was still held for many years afterwards, as at the time the Copernican system did not offer better predictions than the geocentric system, and it posed problems for both natural philosophy and scripture. The Copernican system was no more accurate than Ptolemy's system, because it still used circular orbits. This was not altered until Johannes Kepler postulated that they were elliptical (Kepler's first law of planetary motion). With the invention of the telescope in 1609,
Long Term Ecological Research Network Long Term Ecological Research Network The Long Term Ecological Research Network (LTER) consists of a group of over 1800 scientists and students studying ecological processes over extended temporal and spatial scales. Twenty-six LTER sites cover a diverse set of ecosystems. It is part of the International Long Term Ecological Research Network (ILTER). There are 28 sites within the LTER Network across the United States, Puerto Rico, and Antarctica, each conducting research on different ecosystems. LTER sites are both physical places and communities of researchers. Some of the physical places are remote or protected from development, others are deliberately located in