Astronomy Frontier paper Research Example | Topics and Well Written Essays - 1500 words

Astronomy Frontier - Research Paper Example Recent discoveries by the astronomers illustrate that BHs are the major partner to expand the galaxies. Before finding the activities of black holes, it is necessary to mention here the size and shape of BHs. A black hole is observed by three factors: All these three factors, mass, gravity and emission of radiations, are responsible to generate accretion. McClintock is of the opinion that this is common notion among the astronomers that accretion is one of the main originators of the universe. The accretion disks have powerful influence on galaxy. The energy, produced by the motion of accretion disc around black hole, generates stars development, builds or destroys galaxy structure, and reloads the large amount of elements which has a constructive engagement for planet construction. There is a great question, partially answered, that â€Å"what is the actual relationship between galaxy and black hole?† â€Å"Why are the black holes necessary for galaxy?† â€Å"Why do galaxies generate the black holes in it?† The astronomers have discovered that early galaxies (about 4 galaxies) were 30 times large to black holes in them. But every galaxy has black hole in center so it has been concluded that the black hole generates stars around it and then galaxy breeds (Cattaneo and Best 518–523). Practically, almost all the big galaxies congregate a BH in it. The black holes vary in size and mass. It can be in millions of cosmological masses. As the mass and quantity of black holes increase the galaxy gains a great change in it. The activities of accretion discs enable galactic nuclei to gain the heat and eject the heavy gases from it. Jeffrey E. McClintock, Ph.D., Senior Astrophysicist, Smithsonian Astrophysical Observatory, says: â€Å"There is strong evidence that a supermassive black hole lies at the center of the Milky Way. Astronomers believe this black hole is a radio-wave source known as Sagittarius A* (SgrA*). The

Identify and Critically Evaluate Ecotourism Essay

Identify and Critically Evaluate Ecotourism - Essay Example Moreover, less developed countries want to join tourism fever and appeal for investors to get money to their countries. This is where the roots of ecotourism come from. Though ecotourism is rather new field of human activity and it has not still been discovered if it is an aspect of mass tourism or an independent phenomenon of human activity. The interest of the world’s community to indigenous cultures and remote lands predict a great success to ecotourism. Further research is focused on considering ecotourism as aspect of nature based tourism. People are anxious about overall industrialization and technocratic society. They want to overcome their alienation from nature. Ecotourism is a perfect alternative to mass tourism that â€Å"frequently led to resource depletion and negative impacts on the values of local people and their cultural heritage. Pollution and over use, which degraded the beauty of many of the sites, became common occurrences† (Parks and Allen, 2009). Moreover, an important role of ecotourism can be explained by its main advantage – to preserve indigenous nature and remote land. Therefore, a public attention to nature preservation is determined in the framework of recycling programs, emissions reduction laws and regulations and development of nature preservation programs on the global level. ... The root of the problem lies deep inside the appearance of ecotourism as a separate field (Donohoe & Needham, 2006). The term ecotourism appeared in the academic literature in the middle of 80s. Currently, it is a specific field of studies in tourism and a separate sphere of activity that is differentiated from tourism as such. Sometimes ecotourism is perceived in the framework of an alternative tourism (Blamey, 1997; 2001). Therefore, conventional mass tourism may be interpreted as an external environment for ecotourism development. The main part of ecotourism niche is set by different private sector businesses (ecotour operators) and corresponding alternative attractions (e.g. cableways and submarines that make an access to different inaccessible easier). Thus, there is a need for alternative operators and firms mediating ecotourism (Donohoe & Needham, 2006). A level of businesses involved in ecotourism ranges from private small businesses to large transnational corporations. Anoth er important and wide-spread model of ecotourism is community-based model of service provision in this sphere (Donohoe & Needham, 2006). A specific nature of ecotourism raises specific issues for ecotourism operators’ considerations. These are accessibility and low costs of natural resources. From different perspectives, scientists and researchers have found different peculiarities of ecotourism development. In accordance with Donohoe & Needham (2006), the example of South African ecotourism supports the fact that cooperation of ecotourism operators with small communities is a perfect way to reach an enormous success in this sphere of activity. Further on, it is underlined that the more competitive clusters within ecotourism exist, the more successful this sphere is (Blamey,