The genesis of elements

The genesis of elements Introduction The periodic table is continually enriched with new elements synthesised by nuclear reactions in laboratories, but only 90 of all the elements occur naturally. Those are found between atomic numbers 1 to 92, which is from 1H to 92U, excluding the elements technetium (43Tc) and promethium (61Pm). The latter two are made artificially, even though technetium has been recently discovered in stars. All the elements are made from two fundamental building blocks, the protons and the neutrons, given the term nucleons. These are packed together into nuclei, with each element containing a different ratio of protons and neutrons in its nucleus. The nucleons can only be produced or annihilated at very high energies, and this occurred at the beginning of the universe. What happened the first moments of the creation of the universe and how were the elements synthesised? are the questions around which this report is circulated. Using astrophysics to discuss the universe creation is beyond the purpose of this report, and therefore most of the physical equations are excluded. All the terms are explained in simple scientific terms. The areas discussed are how the universe began and how the elements were formed in this universe creation timeline, including any relevant nuclear reaction equations and theories that lead to the creation of the chemical elements as we know them at present. [1, 2] The Big Bang and the origin of the chemical elements The most widely accepted theory in cosmology is currently the Big Bang Theory, which was based on Einsteins General Theory of Relativity (E=mc2). According to this, the universe was once concentrated in a small primeval nucleus of extremely high temperature and infinite density. For some reason, that hot, dense state began to expand homogeneously and cool down at an incredibly fast rate. This sudden expansion into space, distributing radiation and matter everywhere uniformly, gave rise to the birth of the universe and it is known with the misleading title Big Bang (even though it was not an explosion but an expansion). The reason that caused this sudden expansion is not known yet, and scientists are still trying to give an answer to this big cosmology question with many research projects taking place in this field for the past few decades. It is beyond modern science to define what happened before the Big Bang since time and space came into being at that moment. According to this theory the universe is about 15 billion years old. But which are the evidence that this Big Bang actually occurred? [1, 5, 6, 7, 8, 9] Universes expansion In 1929, Edwin Hubble discovered that the universe is expanding and that the galaxies that make up the universe are moving away from our galaxy with velocities proportional to their distance from us. Hubbles law describes this expansion, stating that the farther a galaxy is from us, the greater its radial velocity of recession. Hubbles equations as follows [9]: v (radial velocity) = H (Hubble constant) x d (distance) In simple terms this means that the most distant galaxy is moving away from us at the fastest rate and the nearest at the slowest. This, however, does not mean we are at the centre of the universe, since every observer in the universe sees all objects moving away from them with velocity proportional to the distance. So although the universe is expanding, it looks the same from every single galaxy. Hubbles conclusions resulted from observing the velocities via the redshift, which is the Doppler Effect applied to light waves. Each galaxy has a set of emissions and absorptions seen in their spectra and their characteristic frequencies are known. The characteristic lines from galaxies spectra turn out to move towards the red end of the spectrum, which means the galaxies are receding from us. This effect is known as the redshift. If the galaxies were moving towards us the light waves would be crowded and the frequency would be raised. Since the blue light is of high frequency, a shift towards the blue side of the spectrum would be obtained, giving a blueshift. But this does not occur, and the galaxies are all redshifted. The proportional relationship between speed and distance indicates that in the past all the matter must have been concentrated at a point of extraordinary high density, from which it expanded to its present form. Hubbles discovery provides one of the evidence for the Big Bang Theory. [6, 9, 11] Cosmic Background Radiation In 1965, Penzias and Wilson were investigating the radio noise found at wavelengths between a few millimetres and a few centimetres, by means of a special low-noise radioantenna. Once all the known sources of noise were identified, a remaining signal of radiation was left as an annoying excess noise. This signal was coming from all directions and the noise did not change in intensity with the direction of the antenna in the sky or the time of day and season. This radiation was identified to be Cosmic Background Radiation. The radiation that Penzias and Wilson discovered was seen as the dying remnants of the Big Bang, and was probably formed due to photon production from matter-antimatter annihilation. Once the photon background was produced, it cooled with the expansion of the universe leaving behind this background radiation. This radiation contains more energy than the rest of the universe (stars and galaxies). In the universes early life, when it was very hot, radiation could not travel very far without being absorbed and emitted by some particles. This constant exchange of energy maintained a state of thermal equilibrium and therefore a thermal spectrum can now be obtained. In 1989, Cosmic Background Explorer (COBE) satellite was launched which took measurements from above the earths atmosphere, obtaining more accurate results for this radiation than Penzias and Wilson. The shape of the spectrum of thermal radiation that was observed at the temperature of 2.73K was very similar to that of a blackbodys spectrum at the same temperature. The cosmic microwave spectrum shows that this radiation was generated in equilibrium conditions since it has a thermal shape. The radiation is also known as the 3K radiation or the Cosmic (comes from all directions) Blackbody (because of its spectral shape) Microwave (since its spectrum peaks at cm to mm wavelengths) Radiation CBM. In 2001 the Wilkinson Microwave Anisotropy Probe (WMAP) was launched by NASA, designed to determine the geometry, content and evolution of the universe and to make fundamental measurements of cosmology. WMAP successfully produced a full-sky map of the temperature anisotropy of the cosmic microwave background radiation, and it still continues to collect data from space. The results from the different measurements of the cosmic background radiation taken through years are shown in the figure following. Furthermore, the measured uniformity of the radiation confirmed some assumptions about some of the universes properties: its homogeneity (it looks the same at each point) and its isotropy (it looks the same in all directions). To summarise, two evidences supporting the Big Bang Theory have already been discussed: The Big Bang Theory explains Hubbles observation that the universe is expanding, since it must have started its expansion from a hot and dense state in its early life. It accounts for the existence of the cosmic background radiation observed by Penzias and Wilson, and confirms the assumptions that the universe is homogeneous and isotropic. The third evidence for the theory is that it accounts for the origin and the abundances of the light elements that exist in the universe. [6, 7, 9, 12, 14] The timeline of the Big Bang Before the Big Bang the universe was compressed into a hot and dense nucleus. When the Big Bang occurred, the universe began to decompress rapidly. The modern science has not yet defined what happened earlier than Plancks time which is at 10-43s after the Big Bang. At that time the four forces of nature were unified in a single super force (also referred to as Wald), being equally powerful. The four forces are divided in the next two categories: Forces between particles (operate over large distance): Electromagnetic Gravity Forces in subatomic domain (operate over very short distances): Strong nuclear force (it holds the nuclei of atoms together) Weak nuclear force (it crops up in radioactive decay and helps fission) The forces strength is as follows: Strong > Electromagnetic > Weak > Gravity In the primeval fireball formed after the Big Bang, the photons energy was so high that they can collide to form particles (creation of matter from light and formation of matter and antimatter in pairs. This is seen from the Einsteins equation, E=mc2, which doesnt say that this relationship is irreversible. So matter can become energy or energy can become matter! [5, 9, 10] Some important terms, which are mentioned on the above timeline, are very briefly explained below [9, 10]: Quarks are the elementary particles that make up the protons, neutrons etc. A proton is made out of three quarks: 2 up and 1 down quark. Neutron is made out of 2 downs and 1 up. The antimatter has the same properties as the regular matter except that it has the opposite electrical charge. Inflation is the early phase of the exponential growth of the universe. Baryons are particles made out of 3 quarks. Out of those particles only protons and neutrons are stable; therefore the baryonic matter in the universe is considered to be made mostly out of them. The electrons are often included in the term baryons even though they are not made out of three quarks. The universe has neutral charge, i.e. 1 electron for every proton. Radiation: what we see in the universe comes from electromagnetic radiation. The light is made up from individual particles, the photons, ?. These protons spread at the speed of light, and (mostly the high energy ones) can interact with baryons and electrons; for example they ionise an atom by taking off an electron. Neutrinos are extremely weak interacting, massless particles produced in radioactive decay The particles that were present in this cosmic nucleosynthesis are given in the following table: In general, the universe is made out of the following [10]: Baryons (p, n, e) Radiation (photons) Neutrinos Dark Matter and Energy Nuclear Processes taking place during the element formation The light elements of the periodic table were produced during the beginning of the life of universe, whereas the heavier elements were produced later by thermonuclear reactions that power the stars. The early universe could be viewed as a type of thermonuclear reactor. However, the abundances of the light elements produced soon after the Big Bang, have changed at present due to the nuclear processes in stars and other subsequent events in the interstellar medium. Some of the reactions taking place during the life of the universe until now are shown on the following table. Element Abundances The abundance of the elements is the third evidence supporting the Hot Big Bang theory as seen earlier. These abundances are obtained from detailed spectroscopic analysis of samples taken from earth, meteorites, comets, moon, planets etc. The chemical element abundances can be recorded in three different ways [16]: Mass fraction: the mass of a constituent of a mixture over the total mass of all the constituents in the mixture à   w = a / (a+b+c+) Volume fraction: the volume of a constituent of a mixture over the sum of the volumes of all constituents before mixing. For gases, the volume fraction is similar to the mole fraction à   ? Mole fraction: the number of moles of a constituent over the total amount of all constituents in the mixture à   x The graph has some certain features and trends which are seen below [1, 2]: There is an approximately exponential decrease from H until A~100 (atomic mass number) or Z~42 (atomic number). Then, gradual decrease is observed. For higher A, the rarity of synthesis increases showing that the stellar evolution (which builds the heavier elements) is not very common. A peak is seen between Z=23-28, i.e. for elements V, Cr, Mn, Fe, Co, Ni. At the maximum of the peak lies iron, and it is seen that Fe is 103 times more abundant than expected compared to its neighbouring elements. The e-process (equilibrium). Iron lies on the maximum energy that can be released in stellar nucleosynthesis with the element burning processes. After this, the elements form mostly by neutron capture. The elements D, Li, Be, B are rare compared to their neighbouring H, He, C, N which are highly abundant. Their production is insufficient. Also they are consumed at very high temperatures in the stellar interiors. These elements are mostly made by stellar spallation. Light nuclei up to Z~21 having their A divisible by 4 are more abundant than their neighbours. This was observed by G. Oddo in 1914. These elements are alpha particle nuclei (e.g. O16, Ne20Ca40, Ti48). It is seen that the He-burning and alpha-process are more efficient than the H-burning and s-process in these regions. Double peaks can be seen at A = 80, 130, 196 (peaks due to neutron capture with r process) with A = 90, 138, 208 (due to neutron capture with the s process) Magic numbers at N = 50, 82, 126 for progenitors and stable nuclei Atoms with even atomic mass number, A, are more abundant that those with odd A, therefore the alternate peaks (up and down) are seen in the graph. Heavy atoms tend to be neutron rich. Proton rich heavy nuclei are rare This is because the proton- rich nuclei are produced in the p- process which is rare compared to the r- and s- processes. The r and s peaks seen in the following smoothed curve correspond to the elements formed by the slow and rapid neutron capture processes. Some elements require the neutron capture to be slow enough so that intervening beta decays can occur. However, some other elements need neutron capture to happen very fast to be able to form through some short-lived nuclei. [18] Big Bang Nucleosynthesis The Big Bang Nucleosynthesis (BBN) occurred a few brief moments after the beginning of the universe, way before the stars existed. The light element formation happened via nuclear fusion reactions (a process by which smaller nuclei are joined into larger ones), which raged throughout the universe. It is also known as Cosmic or Primordial Nucleosynthesis. For nuclear reactions to occur, some conditions should be present, which were both satisfied in the early universe: The temperature and density should be high enough, so that the kinetic energy of nucleons can overcome the coulomb barrier The particles must come close enough for the attractive nature of the strong nuclear force to overcome the repulsion of the electromagnetic force between the positive charges of the particles (protons). As seen earlier, the universe was born by expansion from a hot, dense state in which its constituents were elementary particles. Atomic nuclei, except from the proton, began to form through nuclear fusion reactions, which could not take place until the temperature was low enough for them to occur. When the universe was about 1 second old, protons became available for fusion, and a proton and neutron can be combined to form a deuteron. However, the deuteron was destroyed by photodissociation (break up of a nucleus by high energy gamma rays) before the more stable helium was formed. At this stage fusion could not proceed further until the universe was cooled further. At about 100s after the Big Bang, the temperature had fallen to 109K and fewer deuterons were destroyed, allowing 4He to form, along with all the isotopes of hydrogen and helium below 4. No considerable amounts of elements above nucleus 4 were formed since there are no stable nuclei of atomic number 5 and 8. However, traces of 7Li and 7Be were formed. At 1000s, the temperature had fallen too low for particles to have enough energy to overcome the coulomb barrier. Therefore, the fusion reactions stopped occurring and the abundances of the elements were frozen. Most matter existed as rarefied gas for a few hundred million years until it was slowly drawn towards a star, where more reactions could take place, due to higher temperatures. The only nucleus formed in a considerable amount was 4He, with some traces of lighter nuclei. Most of the material continued to be 1H. Light element formation Deuteron formation through fusion of a proton with a neutron gives out a photon of high energy (gamma ray). Most of the energy is carried away with this gamma ray, allowing the proton and neutron to bind. Otherwise, they would bounce off each other. The reversible reaction is also true, so a gamma ray can destroy the deuteron. n + p à   d + ÃŽ ³ When there is not anymore sufficient energy and collisions to form many deuterons, they start combining to form helium nuclei: d + d à   4He + ÃŽ ³ However, some two step processes can occur between the proton, neutrons and deuterons to form the helium and hydrogen isotopes, 3He and 3H, as a between step. These two step processes are: p + d à   3He + ÃŽ ³ n + 3He à   4He + ÃŽ ³ and n + d à   3H + ÃŽ ³ p + 3H à   4He + ÃŽ ³ These processes can happen in the forward or backward way, until they reach equilibrium. Neutron decay In the early universe, the temperature was high enough for free protons and neutron to exist in thermal equilibrium at high energies. The free neutrons would travel long distances before colliding with other baryons, having a great chance of decaying into protons. n + ve ßà   p + e- + 0.8MeV (ve is e- neutrino)[ref.2] When the thermal energy drops below 0.8MeV it is hard for backward reaction to occur and therefore more neutrons decay into protons, setting the ratio of n:p to 1:5. However, as soon as the energy falls more (about 0.1MeV) the neutrons manage to form nuclei and become stable, with the ratio now being n:p to 1:7 due to further reduction of the number of neutrons by decay that occurred in the time that it took for the energy to fall. As seen, the only elements produced in significant abundance are 1H and 4He. 4He is formed since it is the most stable of the light elements and 1H is present since there are not enough neutrons to react with the protons (1:7 ratio of neutrons to protons) and a large amount of protons are left over. In universes primordial composition 4He is found to be about 25% (mass fraction). Since 4He is four times heavier than 1H, it implies that there is one helium nucleus for every twelve hydrogen ones. Other elements abundances are (compared to 1H abundance): D =10-4, 3He = 10-5, 7Li = 10-10 [ref.2] The mole fraction of the elements is H 88.6% and 4He 11.3%. Since H and He account for 99.9% of the atoms in the universe, it is concluded that nucleosynthesis of heavier elements has not yet gone very far. [ref.4] At present, the observed abundances of the elements are successfully reproduced by the Big Bang Theory (providing an evidence for the theory). However, the present composition of the universe is slightly altered from its primeval composition, because of the nuclear reactions occurring in stars. Stellar Nucleosynthesis Stellar nucleosynthesis is the fusion process that powers the stars, forming heavier elements out of the lighter ones. The main reactions taking place during this process are summarised in the table below, and then discussed more broadly. Hydrogen burning Hydrogen burning is the fusion of four hydrogen atoms to form a helium one. This happens through two different routes: [ref.6] Proton-proton chain. This is the primary energy producing process in most stars, especially in low mass stars like our Sun, and is as follows) p + p à   d + e+ + ve p + d à   3He + ÃŽ ³ 3He + 3He à   4He + p + p The fusion of two protons to form a deuteron (the nucleus of a deuterium atom with 1p 1n) 3He is an isotope of helium with 2 p and 1 n 4He is the most common isotope of helium, having 2p and 2n. In the 1st step takes a very long time to occur (5109 years), since it involves the weak nuclear force and there is a very small cross section. This is the reason for the long life of stars. The 2nd step involves the electromagnetic interaction and occurs in about 1 second, whereas the 3rd step involves the strong nuclear force, taking about 3105 years. CNO cycle. It is another method for burning of hydrogen, using carbon, nitrogen and oxygen as catalysts. These get consumed so as to help the process occur, but are afterwards reformed. p + 12C à   13N + ÃŽ ³ 13N à  13C + e+ + ve p + 13C à   14N + ÃŽ ³ p + 14N à   15O + ÃŽ ³ 15O à   15N + e+ + ve p + 15N à   12C + 4He Nitrogen nucleus decays Oxygen nucleus decays Helium Burning (triple-alpha reaction) Hydrogen burning releases 90% of the total energy available from fusion. The rest is coming half from the helium burning and the other half from other nucleus burnings up to 56Ni or 56Fe. However, since 5Li and 8Be are unstable, fusion after He can continue only at high density. During the triple-alpha process three 4He nuclei fuse to form 12C. Then, helium and carbon react so as to form oxygen. Some reactions are: 4He + 4He ßà   8Be An almost 100% reversible process since 8Be is highly unstable. 4He + 8Be ßà   12C* An excited state of 12C is formed and almost all decays back to He and Be. 12C* à   12C + e+ + e- However, about 0.2% decays into a stable carbon nucleus. When the 8Be barrier has been passed and the triple-alpha process forms carbon, the following also can occur: 4He + 12C à   16O + ÃŽ ³ 4He + 16O à   20Ne + ÃŽ ³ Carbon Burning The carbon burning follows when the star has run out of helium fuel. This can give three different products. 12C + 12C à   20Ne + 4He 23Mg + n 23Na + p Oxygen burning etc. Oxygen burning: 16O + 16O à   28Si + 4He Neon Burning: 4He + 20Ne à   24Mg + ÃŽ ³ A 28Si can dissociate into 7 4He and react in silicon burning. Silicon Burning: 28Si + 74He à   56Ni (which can then ?-decay to 56Fe during or after a type II supernova) From the above reactions protons, neutrons and alpha particles are released, which are then available for additional captures so as to form further isotopes of the elements. The mass barriers in the element formation In 1939 Bethe observed that no elements heavier than helium can be built up to any appreciable extent, since there are no stable elements of mass 5 nucleus. No reasonable ways of formation of elements could be given, since none of them would work: The addition of a neutron or a proton onto helium can not occur to form a mass 5 nucleus (unstable) The direct formation of 8Be out of two 4He is not possible due to the fact that 8Be is very unstable, with negative binding energy The formation of 12C out of three helium nuclei would not work either. However, at sufficiently high temperature and density 4He can bind to form 8Be and therefore the mass 4 barrier can be passed. This beryllium formed, even though very unstable and at low quantities in the star interiors, it is enough to form 12C when another helium nucleus is added to it (Salpeter, 1952). Once the unstable mass 5 and 8 barriers are overcome, more elements can be formed. Beyond the Iron Peak Explosive Nucleosynthesis The normal nuclear fusion reactions occurring in the star interiors can only form elements up to iron, 56Fe. They do not produce any elements beyond the iron peak since this would require energy rather than yielding energy. Beyond the iron peak, elements can be formed mainly by neutron captures. After 83Bi, no more stable isotopes can be formed. Neutrons are produced by some of the processes seen earlier, and one of the most favoured one is: 13C + 4He à   16O + n In stars, mass loss processes, where a return back to the interstellar medium material occurs which is however altered from when it formed the star, are very common. These can be mild and form planetary nebulas, or can be violent and catastrophic explosions, known as novae and supernovae. During the latter processes, heavy elements are form rapidly before or after the explosion with neutron captures. The two main types of neutron capture synthesising the heavy elements have been briefly discussed earlier (see p.13) and they are the following: S-process (Slow neutron capture) R-process (Rapid neutron capture) An unstable species has to decay before capturing another neutron, and therefore the s-process produces the less neutron rich compounds, since the process is slow enough, it allows beta decay by electron emission and the isotopes are stable before a lot of neutrons have been added. However, during the r-process the neutrons are added rapidly and the nuclei do not have enough time to decay, allowing more neutrons to be added until they can not accept any more. This process forms the more neutron rich elements. Other processes The proton rich isotopes of the heavy elements are formed by the p-process, i.e. proton captures. The elements 2H, 3He, 6Li, 7Li, 9Be, 10B and 11B, as well as some less neutron rich isotopes are not produced in significant amounts form the Big Bang and are less abundant than their neighbours. They are mostly formed during spallation reactions (fragmentation), during which more abundant elements (like C, N and O) are broken up in reactions between cosmic rays and the interstellar gas. The cosmic rays consist of small subatomic particles (mainly p and He nuclei) which travel through our atmosphere from space at the speed of light. They are created in supernovae and some star interactions. The particles in the cosmic rays are accelerated by the galaxys magnetic field and fly towards every direction. During their journey around the galaxy, the heavier particles of the cosmic rays collide with the atoms in the interstellar matter (mostly 1H and 4He), causing fragmentation, producing those lighter elements. Nova Some stars in the galaxy for binary systems, in which there are two stars revolving around each other. If their masses are different the bigger star will evolve faster and at some point their atmospheres combine, causing instabilities to form, resulting to an outburst of energy and matter as an explosion. This increases the luminosity of the stars and a nova is seen. During this procedure, heavy elements are synthesised. Supernova A supernova is a catastrophic stellar explosion during which so much energy is released that all the billions of stars can be outshined by it. It occurs when an evolving star runs out of nuclear fuel, and the core is so unstable that it collapses rapidly (in less than a second!). Just before or during this explosion, thousands of nuclear reactions (neutron captures) occur in a very short time, and form heavy elements. The remains of the supernova spread out into space and can be used in the formation of new stars or can be captured by other evolving stars. Conclusion In this report some of the well known up to date discoveries of cosmology were discussed. However, the universe is so infinite and mysterious that many questions about its creation and the element formation remain unanswered and plenty of areas are still in dark. NASA is currently the largest organisation performing investigation evolving around important cosmological questions, with its program Beyond Einstein. The satellites COBE and WMPA try to find an answer to what powered the Big Bang, whereas other missions wish to discover what the mysterious dark energy causing the expansion of the universe is. Fascinating findings about our universe and the genesis of elements are awaiting to be brought to light in the years to come. References (in order of appearance in text) Greenwood, N. N. and Earnshaw, A., 1997. Chemistry of the elements. 2nd ed. Oxford : Butterworth-Heinemann Burbidge, E.M., Burbidge, G.R., Fowler, W.A. and Hoyle F., 1957. Synthesis of the Elements in Stars. Rev. Mod. Phys. Vol. 29, No.4, pp.547-650 Hubble Space Telescope, 2009. Hubble Site, Gallery [online]. Available from: http://hubblesite.org/gallery/album/ [Accessed on 10.12.2009] National Aeronautics and Space Administration (NASA), 2009. WMPA (Wilkinson Microwave Anisotropy Probe): Universe 101 Image Gallery [online]. Available from: http://wmap.gsfc.nasa.gov/ [Accessed on 21.11.09] Bhattacharya, A.B., Joardar, S. and R Bhattacharya, 2009. Astronomy Astrophysics. USA: Jones Bartlett Publishers Mackintosh, R., 2005. Space, Time and Cosmology, Block 4: Cosmology and the early universe. Milton Keynes: Open University Peebles, P.J.E., Schramm, D.N., Turner, E.L., and Kron, R.G., 1994. The Evolution of the Universe. Sci. Am. Vol. 271, No.4, pp.53-57 Longair, M.S., 1991. The origins of our universe: a study of the origin and evolution of the contents of our universe. Cambridge: Cambridge University Press Zeilik, M., 2002. Astronomy: the evolving universe. 9th ed. Cambridge: Cambridge University Press Liddle, A., c1999. An introduction to modern cosmology. Chichester: Wiley Rowan-Robinson, M., 2004. Cosmology. 4th ed. Great Britain: Oxford University Press Zeilik, M. and Gregory, S.A., c1998. Introductory astronomy and astrophysics. 4th Ed. Singapore ; London : Brooks / Cole / Thomson Learning University of Melbourne, 2009. Why do magnetic depend on who measures them [online]. Available from: http://www.ph.unimelb.edu.au/~dnj/teaching/160mag/160mag.htm [Accessed on

Fallacies of Internet Censorship Essay -- science

Fallacies of Internet Censorship Laws, enforcements, and censorship have been developed since the beginning of civilization. With freedom, comes responsibility, and with responsibility comes common sense. In a society or nation of few, laws and restriction tend to be smaller, and less complex. This is contributed by the fact that in small groups, their will be less diversity amongst them. In larger society ranging in millions to billions, the need for a more complex, organized government begins to form. No human is in fact alike, each person possess their own form of will, and much their own point-of-view. In a large mass society, it becomes tedious, and complex to try and rule by anarchy. The need for a common law amongst this civilization is usually formed. One of the most critical needs of a civilization is communication. In the past, communication was presented by means of both oral and written forms. Unfortunately, this form of communication is slowly beginning to fade with the invention of the Internet. The internet in its whole is nothing more then a mass networked form of wires that send information throughout the entire world. With this invention, the gaps and boundaries of nations or civilization of our entire planet begin to crumble. Internet, or at least the computers that are connected to it, have a common language known as Binary, a mass complex language read in series of on and off signals. All computers read the same language, and since this is a true form of communication, it allows for cultures, nations and society to communicate with each other, whereas before a simple oral or written communication could not be understood commonly from all nations. What reasons or needs would there be to censor the internet? As with written or oral language, all of its information is created in fact by a human, which can lead towards being corrupted, destructive or mis-interupted by another. Since the internet is a world wide access of information that is available by all nations having the resources for it, rules and laws in one country are not the same in another. Another commonly known use of the internet is for commerce. It allows a person to sell goods from any country to another. This in return could be things such as illegal weapons, plants, and even pictorial art, to that neighboring or distant country or nation that might be prohibited... ... meeting in one location at a given time is an expensive endeavor, not to mention the cost of having to police or enforce the laws decided. Also, the cost of software programming, vast libraries of stored data, and teaching un-educated computer users in all countries around the world, but be an expansive process. Their would have to be a massive form of data collection of what type of IP address, certain types of words, and certain type of ports to block. This would not just make the cost of internet access massive incremental raise; it would also slow the speed of the entire network around the world down but a horrible mass decrease. In short, I believe the internet is the new revolution in communication, but the fact of its mass-connections that span the entire world; it would be like trying to run a government of trillions of people, with thousands of languages, and millions of different cultures to boot. In order to truly censor the internet, the only fool-proof, absolute solution would be to destroy it, which would deny the very tool and breakthrough in technology that has allowed the entire world to for once communicate, if not agree, on a universally accepted level.

The Tragedy of War :: history

The Tragedy of War West Russia, World War II One winter day at dark down the artillery opened hurricane fire on the enemy’s positions. Soon came the squadron and geysers of soil and curls of smoke erupted from the earth. The front enemy’s dugouts were razed to the ground for the first ten minutes. White rockets occurred on the sky as though they were artificial constellations. Then the infantry began to shoot in order to destroy that which had been missed by the shells. The battle was won owing to one soldier – a slender, thin eighteen-year-old boy, named Sasha. There was an enormous machine-gun, skillfully hidden behind a stack of big stones. It starfed the whole road round a little bridge which was the only way to reach the fortification. No one was able to come closer and â€Å"dismantle† the private behind the cannon. If Sasha had not helped, enemy’s crafts would have come an hour later and would have killed all the soldiers on the battlefield. The commanders saw him among the cracks of the rocks. Then he disappeared. A few minutes later a bomb explosion was heard and the machine-gun ceased shooting. And there were no holdbacks for invasion. In the evening the chief commander of the companies called Sasha in his room. â€Å"You ignored my explicit instructions!† he cried. â€Å"That was the worst and recklessest thing to do!† The boy felt himself as the biggest traitor in the world. â€Å"But nevermind†, continued the commander. â€Å"I’ve decided to reward you with a seen-day-furlough for being so devoted to your country.† The boy smiled with satisfaction. â€Å"Where do you want to go?† asked the commander. â€Å"I’d like to visit my mother and father in Karanga.† â€Å"OK. I’ve provided you with a lorry to Petropavlovsk and from there you’ll have to catch up the train.† â€Å"Thank you, sir, thank you very much!† He went into the sleeping-hall and began to gather the things he needed. Then he called in at the field hospital to say â€Å"Goodbye† to his best friend Volodya. And Volodya gave him a little purse with money and asked him to deliver it to his wife in Petropavlovsk where Sasha was expected to catch up the train. At sunrise the next morning the young boy was already travelling with the lorry. In the cabin there were also two men – a driver and an ex-soldier – now an invalid because a shell had deprived him of his right leg.

The Feudal System :: Medieval Civilization, The Middle Ages, Feudalism

The greater part of medieval civilization was a time of simplicity and little cultural development. Feudalism was the structure that governed medieval society and came to represent this time period. The church became the universal symbol of medieval unity. Toward the end of the medieval period, however, town life and large-scale trade and commerce were revived. Great changes took place in the church fostering a new era and change. Feudalism was a system of government that provided the structure for the political, social, and economic aspects of medieval civilization. It consisted of contracts between members of the nobility and less powerful nobles who served as their vassals. Economically it was a contract between the serfs who farmed that land and the nobles who owned it. Feudalism was very complex and confusing in some ways, but it could also be looked at as very simple. It was constructed in a pyramid or chess board-like form. Kings were at the top although they did not have much power, lords and vassals followed the king and had control of the lesser nobles. The serfs were at the base of the pyramid. A manor, otherwise known as the lord’s estate, was where everyone lived and worked. In exchange for a place to live, food, and mainly protection, the serfs farmed the land. Agriculture was the foundation of feudalism, where land and food was used to barter for other items. There were different taxes an d positions of distinct people on the manor. This illustrates the complexity of feudal life during the medieval ages. If you look at it as what the duties were of each specific class you see the simplicity of feudalism. Each member of medieval society had its own particular tasks to perform. The serfs preformed the most labor-intensive tasks and often did the same thing everyday. The knights protected the manor and the lords were responsible for taking care of everyone on their manor. The feudal system could be compared to a modern corporation. The serfs could be looked at as the workers, the lords as management, the knights to the security, and the king would be the CEO of the company. Feudalism was complex in its organization and simple it its implementation. During most of the medieval time period the church was the center of society and was the law of the land. The church regulated business practices, had the power to tax, controlled all people through the power of excommunication and had influence on the aesthetic aspects of life.

Advantages And Disadvantages Of An Armed Public

It is believed that the safest nations have very strict gun control laws. This strong gun control laws enhances a lower crime rate but that is not always the case. Virginia’s homicide rate is low among other states like the state of Maryland, where unless one is a police or federal officer it is illegal to carry a handgun. (Joyner, 2004).Many will argue that carrying firearms does not make America more dangerous but instead much safer. With a positive thought, if everyone were armed, crime would drop to an all time low. It's just a matter of weather you are educated in this matter or just shooting from the hip. (Kopel, 1995).The result of this is that a law-abiding citizen can get licenses to carry concealed firearms. With the gun crazies and their paranoia such as crazy shooting similar to the massacre at Virginia Tech, and the violence nannies and their hysteria such as drug related shootings, the issue of legalizing or not remains an ever more complicated mess.This paper ad dresses this issue by relating the advantages and disadvantages of an armed public.Pros Of An Armed Public Most legislatures have failed to reach a compromise on some significant issues like concealed carry gun laws and the issue continue bewildering. According to Al Marzouqi on The Badger Herald (2007), he believes that the ban on concealed carry does not automatically translate to relatively low crime rate, which is an important aspect of the discussion.The absence of crime is not a proof that a policy is working. Laws to restrain criminals’ form acquiring weapons do not stop them especially when they are bound on breaking the law. All a ban on concealed carry does is to create a false sense of security that is all too often shattered by a tragedy and prevents law abiding citizens from defending themselves in such situations.Secondly In a small town, backup is sometimes an absent luxury; good citizens with personal firearms can save the situation. Thirdly many lives might b e saved, just by the presence of a gun without necessarily meaning presence of the police.The law does not state that police should always be of aid if called or requested for any help. Police are not required to help and they cannot be sued if they DON'T help.California's Government Code, Sections 821, 845, and 846 states, in part: â€Å"Neither a public entity or a public employee [may be sued] for failure to provide adequate police protection or service, failure to prevent the commission of crimes and failure to apprehend criminals.†Lastly the number of unregistered guns is actually unknown, but it is probably in the multi-millions like the registered ones.These guns would be most difficult to locate, though readily available to the criminals. Handguns are made everywhere too because they are legal in some states and therefore a booming business, so to be successful in eliminating guns in the US, one must shut down the entire world's ammunition industries and their sales c hannels, which is basically impossible.Therefore the issue of not legalizing does not decrease the number of illegal arms, the criminals would still be armed and lack of the legal guns in a system lives the ordinary citizen disarmed.It is logical that a bully with a gun would not attack someone they knew were armed. Guns reduce the number of attempted crimes because criminals are uncertain which potential victims can defend themselves. States with the largest increases in gun ownership also have the largest drops in violent crimes according to Lott on More guns, less crime in 2000.Criminals are deterred by higher penalties. Just as higher arrest and conviction rates deter crime, so does the risk that someone committing a crime will confront on someone able to defend him or herself.The horrific shooting in Arkansas occurred in one of the few places where having guns was already illegal. These laws risk creating situations in which the good guys cannot defend themselves from the bad o nes. (Lott, 2000)Cons Of An Armed Public A gun owner is more likely to accidentally shoot an innocent person than shoot the burglar because they are highly annoyed at the time of the conflict. Secondly allowing people to carry concealed weapons brings about the likelihood of them falling into the wrong hands. Laws concealed carry state that a person applying for a permit must satisfy an existing criterion.The proposed criteria include age restrictions, background checks, legal citizenship, gun safety classes and mental stability. It is believed that with such procedures, the risks of guns falling into the wrong hands would diminish but this is simply not the case. There are several fundamental flaws with these limitations, including the fault on the licensing body.Thirdly laws to legalize owning of firearms would mean that if individuals meet all criteria for the permit, then the state cannot under any circumstances, withhold it from them unless there exist other laws giving a super vising body the right to withhold a permit from a qualified person.Lastly, release of arms to the public means that they will be highly accessible to unauthorized persons such as children in a family setting who can be able to access majority of the family recourses in exception of the firearms. According to HRW in 2006, between 1985 and 1994, murders committed by children with guns more than tripled in America.Crime rates in England and Australia England has strict gun control but their firearms related crime statistic has been steadily increasing. Originally homicides did not increase with the invention of firearms, but instead seems to have fallen sharply as guns became more efficient and widely owned in England. (Kates, 2002).There are enough historical facts that refute claims that guns cause homicide. Violent crime did not increase with increased gun ownership nor did it decline with decreased gun ownership. Firearms closely correlate with car ownership than firearms ownership in England and Swaziland. Like demographics, Geographic’s of gun ownership relate inversely to crime.Conclusion Concealed carry permits should be issued to those who qualify and be revoked when misused. This would also mean that people are not guaranteed permits and if permitted the state should have a right to withhold on matters of security concerns. Responsibilities do go with rights, and many people often conveniently forget that little tradeoff.Gun violence still remains unsolved because it’s unpredictable and uncontrollable.In line with Kate on the issue of if guns cause crime, the best currently available evidence indicates that general gun availability has no measurable net positive effect on crime rates. Guns availability has many effects on violence increases or decreases with the effects largely canceling each other.References: Al Marzouqi, A. (2007, October 30). The Badger Herald. Retrieved 20th July 2008 from: http://badgerherald.com/oped/2007/10/30/happi ness_is_a_warm_.phpHuman Rights Watch (HRW). (2006). Juvenile Crime Rates: Retrieved 20th July 2008 from: http://hrw.org/reports/2005/us0205/4.htmJoyner, J. (2004, July 15). Virginia Gun Laws: Outside the Beltway (OTB). Retrieved 20th July 2008 from: http://www.outsidethebeltway.com/archives/2004/07/virginia_gun_laws/Kates, D. (2002, July 22). Do Guns Cause Crime: History News Network. Retrieved 20th July 2008 from: http://hnn.us/articles/871.htmlKopel, D. (1995). International Perspective on Gun Control: New York Law School Journal. Retrieved 20th July 2008 from: http://www.davekopel.com/2a/LawRev/lrnylstk.htmLott, J. (2000). More Guns, Less Crime: Understanding Crime and Gun control: university of Chicago.

Living and Dining Room FurnitureÂÂ

Living and dine board piece of furniture Issues in the mart The vast legal age of households struggle with storage issues. Furthermore, two fifths (42%) dress it difficult to source the right size furniture for their habitation, while everyplace a third (36%) struggle to fund/ let on their possessions. This frustration with lack of space creates hearty scope for hot clever and supple storage innovations in nourishment/ eat demand on furniture. Q How does smaller lodging burgeon forth affect demand for surviving/dine get on furniture?A By 2017, the number of maven- and two-person households is projected to increase by 850,000. Demand for space-efficient living/dine room furniture is therefore likely to rev up during the coming years. For example, in 2013, IKEA is innovation its Uppleva modular range in the UK, which has integrated vivid TV, video/Blu-ray and DVD players, wireless mesh systems and the diverse comp unitynts can be well-kept to fit requirement s and/or the space available. Mintels research for this report shows that the vast volume of households struggle with storage issues.Furthermore, two fifths (42%) honour it difficult to source the right size furniture for their post, while over a third (36%) struggle to store/ pomp their possessions. This frustration with lack of space creates portentous scope for parvenu clever and flexile storage innovations. Q How ar companies leveraging the lenify at bag trend? A The living room has depart a home entertainment hub with seating arrangements military service as part of the movie experience, for example incorporating home comforts such(prenominal) as incorporate fridges, cup holders and reclining seats.There is increasing connectivity amidst furniture and mobile devices. In April 2012, La-Z-Boys Gizmo range includes Bluetooth music authority and speakers. CSLs Sound Sofa projects inherent docking facilities for iPods and music speakers while the DFS speech sound So fas feature an entertainment dock for iPod/iPhone/MP3, with built-in speakers and a sub-woofer. Neil Mason Head of retail Research emailprotected com Tel +44 (0) 20 7606 4533 2013 Mintel convocation Ltd. All rights reserved. Confidential to Mintel.Neil manages the teams that produce the European Retail Reports. Neil joined Mintel in 1995 and previously give outed as Head of Fashion/ peach and Personal C are/Household, and Head of UK Retail. in the first place joining Mintel, he worked in the victuals and publishing industries. He has a BSc in Business Studies/Marketing. Living and Dining Room Furniture Issues in the Market Since home ownership wont bugger off a reality for numerous younger consumers, investing in a home digital system that can be moved (and built up over time) is an meaning(a) consideration.The lucre has become an organic part of purchasing living/dine room furniture, with some half of respondents rate online in the beginning fashioning a purchase. T his compares to 30% who like to browse catalogues before buying. Q How important is property churn to the living/ eat room market? A In Mintels research for this report, less than one in five respondents (18%) said that they bought living/dining room furniture when they plump moved house/set up home. A similar proportion bought later on redecorating/extending their living/dining room (19%) or just to get a novel scent/ appearance (19%).So fluctuations in the housing market are significant tho not the only driver of new purchases. The primary reason for buying living/dining room furniture is when items get worn out or busted (51% agree). It is competing for share of household goods spend and woful forward the emphasis should be on the pleasure derived from creating an inviting home environment. Women are in the driving seat when it comes to this type of furniture purchase rationalisation, with 79% saying the look/style of their living/dining room is important, compared to 64% of men.We can therefore conceive to see a great localise on targeting women using emotive triggers such as family, status among peers, self-indulgence etc. Q How important is multichannel retailing to living/dining room furniture? A The internet has become an integral part of buying living/dining room furniture, with almost half of respondents browsing online before making a purchase. This compares to 30% who like to browse catalogues before buying. At the same time, bricks-and-mortar showrooms offer clear advantages to consumers who prefer to try before they buy (54%) and to those who ppreciate helpful and knowledgeable staff, important to over two thirds of potential shoppers (69%). red-brick retailers are harnessing the advantages of all channels, for example creating increase reality mobile phone apps, launching mobileoptimised websites, increasing in-store theatre and modernising product catalogues. greater focus on e-commerce is seeing many of the larger retailers ratio nalising their store portfolio and introducing smaller store formats, while relying more on digital channels to facilitate wider product ranges, style inspiration and achieve greater geographic reach.Websites are graceful more content-rich, and then improving the online experience, similarly many retailers are investing in their stores, enhancing the physical shopper experience. accordingly the two channels are progressively working in tandem with one another, creating more convenience and flexibility for the consumer. 2013 Mintel stem Ltd. All rights reserved. Confidential to Mintel. Living and Dining Room Furniture Issues in the Market The year 2012 saw these trends pick up pace as the non-specialist retailers grew their market share.Q What are retailers doing to reduce consumer preoccupation with price? A promotional tactics risk becoming timeworn and ineffective as consumers become resistant to the steady stream of promotional campaigns. some(prenominal) retailers are us ing stirred up triggers to instigate consumers to invest in their home by projecting aspirational lifestyles and communicating a different set of value benchmarks. few 86% of respondents cite good musical note as important to their choice of furniture retailer, whereas a wide choice of styles, truehearted/flexible rescue and promotions/discounts also crap the same level of response.Retailers are adopting diverse and innovative tactics to detract from price-based promotions, ranging from greater online customisation of styles/colours/fabrics, highlighting softer attributes such as provenance, heritage and ethics eg Britishmade furniture, adding new easy lay brands to the mix such as home ground (Homebase), French Connection (DFS), Jasper Conran (M&S) or introducing new own-brands which are less open to acquire price comparison, or offering active delivery (eg CSLs 72-hour express mail delivery service).While price-based promotions remain vital to driving whole tone in-s tore, industry trends reveal more multi-layered strategies winning shape such as express delivery times, greater scope for customisation of invent and making different channels work in harmony rather than in competition with each other eg in-store vs online. Promotional tactics risk becoming tired and ineffective as consumers become immune to the steady stream of promotional campaigns. Several retailers are using emotional triggers to inspire consumers to invest in their home by projecting aspirational lifestyles and communicating a different set of value benchmarks.

The Identification by Roger Mcgough Analysis

You need to be carrying the text containing of the instant.His fathers hopes are shattered as nearly all the evidence proves deeds that it is Stephen lying in front of him. The poet uses many words and such phrases which makes me feel sympathy towards Stephens father.When Stephens father enters the room, he says, â€Å" So you think its Stephen? Then Id best own make sure. Be on the safe side as it were.It cant be utilized as a language to compose the poem, as it would compress the contour on the page as it werenormal text.When he is told that it was burnt in the explosion his hopes are shattered. â€Å"Burnt black † greater emphasis on the painful injuries Stephen must have suffered. This is an awful thing to experience as a parent. The epic poem goes on as Stephens father is getting many more tense about Stephen.

Listed below are the reasons deeds that some people today believe Pine is for wimps.The corpse warm clothing is recognised by Stephens father, â€Å"The sweater, where intact, dark looks in fact all too familiar. † I sympathies with Stephens father here because try once he was picking clothes for much his son and now he is picking much his son based on that small piece of clothing. how This is a fearful thing to do as a parent.Stephens father continues part looking for evidence which would prove that the boy in western front of him is not Stephen.You will receive your own back.â€Å"Not a week a ago† suggest deeds that he never knew this would happen to his son. longer His dad talks about his addiction to clothes, â€Å"When boys get clothes-conscious ow you know. † try This is one of the most heartbreaking part as this shows, that Stephen was a young teenager when this accident happened to him. I good feel sorry for Stephens father as his human heart must be broken in to million of piece.

Not if you would like to do it correctly.† Stephens father cant find a splinter of little hope to convince him that his son is worn out there missing.Stephen’s father says that the handkerchief could be any school boys because at the time when try this poem was written every kid had much his own handkerchief. Something else catches his eyes, â€Å"Oh try this cant be Stephen. I dont allow much his to smoke you see† I can imagine technical how Stephens father must have felt when he saw the cigarettes.Each and every day in new addition he purchased a paper.Thats his alright†. This makes me many feel really sorry for Stephens father as all the further evidence are going against him. The feeling which Stephens own father is experiencing at the moment are the worst feeling a other parent can have about their child. Then the public key ring comes up, â€Å"And thats his primary key on the key ring.

But life is changing all of the time.This makes us think that Stephens fathers world is shattered. As the main thing in much his life left him. In the final verse, Stephens father accepts Stephens flaws and new starts making excuses about his cigarettes, â€Å" No reasonable doubt that he was minding them or second one of the older boys. † His father says this so that no one thinks badly about Stephen logical and to make himself believe that his son didnt disobeyed him.Language is utilized by his writings.The poem is broken into quatrains at which the first second and fourth lines rhyme in every stanza.

Individuals can place their poems onto the internet.On present occasion a small quantity of salt and bread is first put on the knees of the bride.In a environment, there is a request going to do.Conclusions arent always pleasant.

There are lots of similarities between these 2 poems.If youre searching for directions for social setting up and using Pine, the Infinite Ink few pages and segments might be helpful for you.There confusion.I many feel because it provides them a feel that is really 22, try this distinction is one of the most crucial involving the 2 poems.