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| | With your offense, you might eat Gunboats which can handily shoot at enemy rights coming from a prolonged periods of time range and Landing Hobbies which you must clog when you train equipment for example Rifleman, Heavy, Zooka, Warrior and Takes a dive. To your village defenses, you might have structures like Mortar, Hardware Gun, Sniper Tower, Cannon, Flamethrower, Mine, Tank Mine, Boom Cannon and Explode Launcher to assist your family eradicate enemies.<br><br>In the case when as a parent you might be concerned with movie game content, control what downloadable mods are put globe sport. These downloadable mods are usually written by players, perhaps not that gaming businesses, therefore there is no ranking system. May thought was a remarkably un-risky game can turn a lot worse with any of these mods.<br><br>Back in clash of clans Cheats (a resolution popular social architecture or arresting bold by Supercell) participants can acceleration -up accomplishments for example building, advance or training militia with gems that will be sold for absolute cash. They're basically monetizing this player's eagerness. Every amusing architecture vibrant I apperceive of [http://answers.Yahoo.com/search/search_result?p=manages&submit-go=Search+Y!+Answers manages] to participate.<br><br>Purchase attention to how really money your teenager is generally spending on video social games. These products might not be cheap and there is without question often the option together with buying more add-ons from the game itself. Set monthly and on an annual basis limits on the quantity of of money that may be spent on games. Also, have conversations with your boys about budgeting.<br><br>Make sure your child's xbox play enjoying. Video video games are now rated primarily like films and generally can help. This enables you to keep an eye on the information your kids often is exposed to. Depending upon your child's age, continue to keep my man clear of video video game that happen to be a little more meant for people what persons are more fully learned than him.<br><br>To help defeat higher-level villages, this task aids you to use a mixture of troops not unlike Barbarians plus Archers plus those suicide wall bombers to bust down any walls. Goblins can also be a useful focus the combo simply because they attack different buildings. For those who have virtually any questions concerning where along with tips on how to employ [http://prometeu.net clash of clans cheats gems], you are able to e mail us on our own webpage. You should understand when you like to begin worrying pertaining to higher troops when your family can''t win battles now with Barbarians.<br><br>You don''t necessarily have to one of the complex troops to win advantages. A mass volume of barbarians, your first-level troop, most likely will totally destroy an enemy village, and strangely it''s quite enjoyable to take a the virtual carnage. |
| '''''The Sand Reckoner''''' ({{lang-el|Αρχιμήδης Ψαμμίτης, ''Archimedes Psammites''}}) is a work by [[Archimedes]] in which he set out to determine an upper bound for the number of grains of sand that fit into the [[universe]]. In order to do this, he had to estimate the size of the universe according to the contemporary model, and invent a way to talk about extremely large numbers. The work, also known in Latin as '''''Archimedis Syracusani Arenarius & Dimensio Circuli''''', which is about 8 pages long in translation, is addressed to the [[Syracuse, Sicily|Syracusan]] king [[Gelo, son of Hiero II|Gelo II]] (son of [[Hiero II of Syracuse|Hiero II]]), and is probably the most accessible work of [[Archimedes]]; in some sense, it is the first [[Academic paper|research-expository paper]].<ref name="v">[http://www.lix.polytechnique.fr/Labo/Ilan.Vardi/sand_reckoner.ps Archimedes, The Sand Reckoner, by Ilan Vardi], accessed 28-II-2007.</ref>
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| ==Naming large numbers==
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| First, Archimedes had to invent a system of naming [[large numbers]]. The number system in use at that time could express numbers up to a [[myriad]] (μυριάς — 10,000), and by utilizing the word "myriad" itself, one can immediately extend this to naming all numbers up to a myriad myriads (10<sup>8</sup>). Archimedes called the numbers up to 10<sup>8</sup> "first numbers" and called 10<sup>8</sup> itself the "unit of the second numbers". Multiples of this unit then became the second numbers, up to this unit taken a myriad-myriad times, 10<sup>8</sup>·10<sup>8</sup>=10<sup>16</sup>. This became the "unit of the third numbers", whose multiples were the third numbers, and so on. Archimedes continued naming numbers in this way up to a myriad-myriad times the unit of the 10<sup>8</sup>-th numbers, i.e., <math>(10^8)^{(10^8)}=10^{8\cdot 10^8}</math>.
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| After having done this, Archimedes called the numbers he had defined the "numbers of the first period", and called the last one, <math>(10^8)^{(10^8)}</math>, the "unit of the second period". He then constructed the numbers of the second period by taking multiples of this unit in a way analogous to the way in which the numbers of the first period were constructed. Continuing in this manner, he eventually arrived at the numbers of the myriad-myriadth period. The largest number named by Archimedes was the last number in this period, which is
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| ::<math>\left((10^8)^{(10^8)}\right)^{(10^8)}=10^{8\cdot 10^{16}}.</math>
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| Another way of describing this number is a one followed by ([[Long and short scales|short scale]]) eighty quadrillion (80·10<sup>15</sup>) zeroes.
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| Archimedes' system is reminiscent of a [[positional numeral system]] with base 10<sup>8</sup>, which is remarkable because the ancient Greeks used a very [[Greek numerals|simple system for writing numbers]], which employs 27 different letters of the alphabet for the units 1 through 9, the tens 10 through 90 and the hundreds 100 through 900.
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| Archimedes also discovered and proved the [[exponentiation|law of exponents]], <math>10^a 10^b = 10^{a+b}</math>, necessary to manipulate powers of 10.
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| ==Estimation of the size of the universe==
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| Archimedes then estimated an upper bound for the number of grains of sand required to fill the Universe. To do this, he used the [[heliocentric model]] of [[Aristarchus of Samos]]. The original work by Aristarchus has been lost. This work by Archimedes however is one of the few surviving references to his theory,<ref name="a">[http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Aristarchus.html Aristarchus biography at MacTutor], accessed 26-II-2007.</ref> whereby the [[Sun]] remains unmoved while the [[Earth]] [[Orbital period|revolves]] about the Sun. In Archimedes' own words:
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| {{quote|His [Aristarchus'] hypotheses are that the fixed stars and the Sun remain unmoved, that the Earth revolves about the Sun on the circumference of a circle, the Sun lying in the middle of the orbit, and that the sphere of fixed stars, situated about the same center as the Sun, is so great that the circle in which he supposes the Earth to revolve bears such a proportion to the distance of the fixed stars as the center of the sphere bears to its surface.<ref>Arenarius, I., 4–7</ref>}}
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| The reason for the large size of this model is that the Greeks were unable to observe [[stellar parallax]] with available techniques, which implies that any parallax is extremely subtle and so the stars must be placed at great distances from the Earth (assuming [[heliocentrism]] to be true).
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| According to Archimedes, Aristarchus did not state how far the stars were from the Earth. Archimedes therefore had to make an assumption; he assumed that the Universe was spherical and that the ratio of the diameter of the Universe to the diameter of the orbit of the Earth around the Sun equalled the ratio of the diameter of the orbit of the Earth around the Sun to the diameter of the Earth. This assumption can also be expressed by saying that the stellar parallax caused by the motion of the Earth around its orbit equals the solar parallax caused by motion around the Earth.
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| In order to obtain an upper bound, Archimedes used overestimates of his data by assuming:
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| * that the perimeter of the Earth was no bigger than 300 myriad [[Ancient Greek weights and measures#Length|stadia]] (5,55·10<sup>5</sup> km).
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| * that the Moon was no larger than the Earth, and that the Sun was no more than thirty times larger than the Moon.
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| * that the angular diameter of the Sun, as seen from the Earth, was greater than 1/200th of a right angle ( π/400 [[radian]]s, 0.45[[Degree (angle)|° degrees]].
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| Archimedes then computed that the diameter of the Universe was no more than 10<sup>14</sup> stadia (in modern units, about 2 [[light year]]s), and that it would require no more than 10<sup>63</sup> grains of sand to fill it.
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| Archimedes made some interesting experiments and computations along the way. One experiment was to estimate the angular size of the Sun, as seen from the Earth. Archimedes' method is especially interesting as it takes into account the finite size of the eye's pupil,<ref>Smith, William — A Dictionary of Greek and Roman Biography and Mythology (1880) - p.272</ref> and therefore may be the first known example of experimentation in [[psychophysics]], the branch of [[psychology]] dealing with the mechanics of human perception, whose development is generally attributed to [[Hermann von Helmholtz]]. Another interesting computation accounts for solar parallax and the different distances between the viewer and the Sun, whether viewed from the center of the Earth or from the surface of the Earth at sunrise. This may be the first known computation dealing with solar parallax.<ref name="v" />
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| ===Equality between Archimedes' number and Eddington's number===
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| The total number of nucleons in the observable universe of roughly the [[Hubble_volume|Hubble radius]] is the [[Eddington number]], currently estimated at 10<sup>80</sup>. Archimedes' 10<sup>63</sup> grains of sand contain 10<sup>80</sup> nucleons, which means that Archimedes' number equals Eddington's number.<ref>Harrison, Edward Robert ♦ [http://books.google.ru/books?id=kNxeHD2cbLYC&pg=PA482&lpg=PA482&dq=%22eddington+number%22&source=bl&ots=h5cjT6r_e8&sig=tzdX1oFPojjCjQZtYpcDlUDIPhk&hl=en&sa=X&ei=gjcSUIDgBobR4QTJwoCIDQ&redir_esc=y#v=onepage&q=%22eddington%20number%22&f=false Cosmology: The Science of the Universe] Cambridge University Press, 2000, pp. 481, 482</ref>
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| == Quote ==
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| {{quote|
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| "There are some, king Gelon, who think that the number of the sand is infinite in multitude; and I mean by the sand not only that which exists about Syracuse and the rest of Sicily but also that which is found in every region whether inhabited or uninhabited. Again there are some who, without regarding it as infinite, yet think that no number has been named which is great enough to exceed its magnitude. And it is clear that they who hold this view, if they imagined a mass made up of sand in other respects as large as the mass of the Earth, including in it all the seas and the hollows of the Earth filled up to a height equal to that of the highest of the mountains, would be many times further still from recognizing that any number could be expressed which exceeded the multitude of the sand so taken.
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| "But I will try to show you by means of geometrical proofs, which you will be able to follow, that, of the numbers named by me and given in the work which I sent to Zeuxippus, some exceed not only the number of the mass of sand equal in magnitude to the Earth filled up in the way described, but also that of the mass equal in magnitude to the universe." <ref>Newman, James R. — The World of Mathematics (2000) - p.420</ref>|Archimedis Syracusani Arenarius & Dimensio Circuli
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| }}
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| ==References==
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| <references />
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| == Further reading ==
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| The Sand-Reckoner, by Gillian Bradshaw. Forge (2000), 348pp, ISBN 0-312-87581-9.
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| ==External links==
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| *[http://www.lix.polytechnique.fr/Labo/Ilan.Vardi/psammites.ps Original Greek text]
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| *[http://web.fccj.org/~ethall/archmede/sandreck.htm The Sand Reckoner]
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| *[http://www.calstatela.edu/faculty/hmendel/Ancient%20Mathematics/Archimedes/SandReckoner/SandReckoner.html The Sand Reckoner (annotated)]
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| *[http://www.lix.polytechnique.fr/Labo/Ilan.Vardi/sand_reckoner.ps Archimedes, The Sand Reckoner, by Ilan Vardi; includes a literal English version of the original Greek text]
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| {{DEFAULTSORT:Sand Reckoner, The}}
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| [[Category:Ancient Greek astronomy]]
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| [[Category:Mathematics manuscripts]]
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| [[Category:Works by Archimedes]]
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