Several Possible Courses for the Future of the Universe - Assignment Example

1. Briefly relate several possible s for the future of the universe and the kinds of observation that would be necessary to resolve the issue. Two possible scenarios present themselves as possible future courses of our universe, and they are dependent on the overall geometry of the universe. Our universe could have three possible geometries namely, flat, spherical, or hyperbolic. When we talk of the geometry of the universe, we are not talking of some abstract concept, but rather what our universe would look like to an observer positioned outside our universe. The geometry of our universe is the result of the average density of all the matter in it, which we all know is a function of mass. Studies have been conducted to arrive at the geometry of our universe to understand what is likely to be the future course of our universe. The first possible course for our universe is commonly termed the “Big Crunch”, and is virtually the reverse of the “Big Bang” theory, which resulted in the creation of our universe. In essence this possible course of our universe will see it collapsing on itself. This possible scenario will become true, if there is enough matter present to resist the force of expansion at some stage in the future, and will occur if our universe has a spherical shape. A spherical geometry of our universe would indicate that it there is enough mass in the universe to make its average density above the critical density level, which will make it possible to resist the expansion force at some stage in the future. When this happens the universe will start contracting at first slowly and then rapidly and finally compacting into a hot point that would be infinitely hot, small, and dense. There is no idea of what would happen to our universe after it reaches this point in the Big Crunch concept of the possible future course of our universe, though there is popular hope that our universe would continue to oscillate between Big Bangs and Big Crunches. The second possible course of our universe is commonly termed as the “Big Freeze”, in which the universe will go on expanding forever. This scenario will come true, if there is not enough matter to resist the force of expansion, and will occur if our universe has a flat or hyperbolic shape. A flat geometry will indicate that the average density of the universe is exactly the same as the critical density, while a hyperbolic shape would indicate that the average density of the universe is less than the critical density, projecting a scenario of continuing expansion. In the continuing expansion scenario, our universe will continue expanding, and the visible physical aspects of our universe as we see it would disappear, and the temperature of the universe would drop to absolute zero. From 1992 onwards, several joint research studies have been undertaken to understand the overall geometry of our universe. Studying the cosmic microwave background radiation (CMB) has been accepted as a successful means for the understanding of the overall geometry of our universe. The Wilkinson Microwave Anisotrophy Probe (WMAP) under NASA has recently been successful in providing a high resolution image of CMB. Findings from the study of the angular resolution and temperature resolution of WMAP show that our universe is flat, which means the universe will continue to expand unceasingly, though with an ever decelerating rate (1). 2. Outline the stellar nebula theory, and explain how the characteristic properties of the solar system provide evidence that supports that theory. The stellar nebular theory in essence was developed for the purposes of explaining the origin of our solar system. Croll, 1996, p.69, quoting Professor A. Winchell says that the stellar nebular theory is “primarily a genetic explanation of the phenomena of our solar system; and accessorily a co-ordination, in a common conception, of the principal phenomena in the stellar and nebular firmament, as far as human vision has been able to penetrate”. (2). The theory starts with the assuming that all the material that is present in our solar system at one time was in a state of extreme tenuity and diffusion, thus occupying more space and expanded beyond the orbit of the outermost planet in our solar system. Influenced by gravity, this tenuous and diffused mass gradually aggregated to the bodies that are seen in our solar system. The stellar nebular theory thus starts from the basis of a diffused nebulous mass under the influence of gravity, and makes no attempt to probe how this diffused stellar originated and what was its state prior to the process of being pulled together. (2). However, since the stellar nebular theory was developed to explain the origin of the solar system, then the characteristic properties of the solar system must support the hypothesis of the theory. The characteristics demonstrated by the sun and the planets in our solar system show that there were some definite laws that governed their formation, rather than a disorganized development of the sun and the planetary bodies. The stellar nebular theory suggests that the sun was coalesced first, and the rest of the planetary bodies developed thereafter from the residues of the nebulous mass thrown out when the sun coalesced. This is supported by the symmetry seen in our solar system. Every planet in our solar system occupies its own definite space in isolation. The orbits of all the planets with the exception of Mercury and Venus can be taken as being almost circular. The planets orbit around the sun in the same plane. All the planets revolve round the sun in the same direction as its own rotation. The satellites of the planets also follow the same pattern of rotation, mimicking the rotation of their parent planets. The planetary system presents a highly differentiated character. The asteroids in the asteroid belt show no similarities to the inner or outer planets of our solar system. The comets do really present themselves as a part of our planetary system, but distant visitors that are very old icy fragments. (2). 3. Earth is considered a unique planet due to the five sub-spheres or sub-systems it has operating on it. These are Earths lithosphere, hydrosphere, cryosphere (ice), atmosphere, and biosphere. Compare and contrast the planets Venus and Mars with regard to their either having or not having these sub-spheres. See the list below. Atmosphere O2CO2 Hydrosphere H2O liquid H2O gas Parameters Venus Mars Atmosphere Yes Yes O2CO2 No Yes Hydrosphere No No H2O Liquid No No H2O Liquid No No (3) 4. Discuss the minor members of the solar system such as comets, meteors, and asteroids. Include in your answer their origin, properties, and geology, where it applies. Our solar system is believed to have started forming around five billion years ago, from the diffused nebular mass that is supposed to have been made up of gas and dust. A very large proportion of this nebular mass was taken up in the formation of the sun. The remaining part of the nebular mass continued to revolve around the sun and gradually coalesced into the planets and moons of our solar system. The remaining lumps of matter travelled through the space between the newly formed planets and moons to the edge of our solar system, and are called comets, meteors, and asteroids. Thus the origin of the comets, meteors and asteroids is from the same diffused nebulous mass from which the sun, planets, and moons of our solar system was formed. (4). Rock, ice, and metals are the main constituents of comets, meteors, and asteroids. However, in comparison of the composition between the three, meteors and asteroids are mainly made up of rock with a little metal, while comets are made up of a mixture of ice, rock, and dust. This composition of comets has given them the nick name of “dirty snow balls”. (4). Works Cited 1. “Future of the Universe and Possible Death”. 2006. 12 Dec. 2010. http://burro.astr.cwru.edu/stu/advanced/cosmos_death.html 2. Croll James. Stellar Evolution and Its Relation to Geological Time. New York: BiblioLife, Llc. 2009. 3. Seeds, A. Michael. The Solar System. Sixth Edition. Belmont, CA: Thomson Higher Education, 2008. 4. Kerrod Robin. Asteroids, Comets, and Meteors. Minneapolis, MNL Lerner Publications Company, 2000. Read More