Study Of Use Case Diagram References-: Theory-: That Form The: Fill & Download for Free

Matthew Funke has already provided a simple and correct answer to this question. But I happen to have an illustration at hand to go along with this, so here it goes:It’s not very often that I get to draw a physical diagram in a Moon-centered frame of reference! What’s that, selenocentrism?For a fuller discussion, you can see Sec. 2.3 in the paper “A physical approach to dissipation-induced instabilities”, which I wrote recently with a student, Carlos Díaz.The physics of this process has been well understood for a long time. (For a summary of the history, see the Wikipedia article on “tidal acceleration”.) But we discussed it in our paper because we think that it provides a useful analogy for many other “dissipation-induced instabilities” for which the corresponding theory hadn’t been treated as clearly in the physics and engineering literature.The Moon’s tide deforms the Earth, especially the fluid part of it. As the Moon orbits around the Earth, it drags the tidal bulge along. If there were no internal friction opposing the motion of this tidal bulge, the bulge would always point straight towards the Moon, and high tide would coincide with the Moon’s “culmination” in the sky (i.e., with the time when an observer at a given geographical position sees that Moon at its highest elevation above the horizon for that day).But, in fact, there’s an internal friction: viscosity tends to slow down the motion of seawater with respect to the solid seafloor. The tidal bulge therefore lags behind the position of the Moon in the sky. High tide tends to happen a couple of hours after the culmination of the Moon in the sky (the exact delay depends on how much the friction with the solid Earth obstructs the motion of the tide around a particular location along the seacoast).In the picture above, a person standing at geographical position G will always see the culmination of the Moon first. The Earth must then rotate about its center by an additional angle [math]\phi[/math] before that person sees the high tide.If you study the figure carefully, you should be able to convince yourself that, because the period of rotation of the Earth about its center (a day) is shorter than the period of the orbit of the Moon around the Earth (a month), the net gravitational force that the Moon exerts upon the Earth has a small tangential component (marked by F in the picture) that powers the motion of the Earth around the Moon. Therefore the Moon-Earth orbital motion is gaining in energy. The radius of the Moon-Earth orbit is therefore increasing by about four centimeters every year.Where does that energy come from? You can figure out the torque that the Moon’s gravitational pull exerts on the tidally deformed Earth, with respect to its center. In the above picture this torque acts against the Earth’s rotation, slowing it down. So what’s happening is that the orbital motion is being powered at the expense of the Earth’s rotation. Actually, at all times the Earth is losing more rotational energy than the energy gained by the orbit of the Moon around the Earth, because some of the energy is dissipated as heat by the friction that produces the lag of the tidal bulge with respect to the Moon.This means that the days are getting longer, until eventually the day and the month will be equal. After that, the Moon will always see the same side of the Earth and no further tidal acceleration will occur. This is called “tidal locking”. In fact, this process has already run its course for the Moon’s rotation, which is why we always see the same side of the Moon facing us on here on Earth.As Matthew Funke pointed out in his answer, there are also cases, like the orbit of Phobos around Mars, in which the planet’s rotational period is longer than the moon’s orbital period. It’s a good exercise to re-draw the figure for such a case. You should find that the moon’s gravitational pull on the planet speeds up the planet’s rotation at the expense of the orbital motion. Again, only a part of the energy that comes out of the orbit is transferred to the planet’s rotation, because some energy is dissipated by the tidal deformation of the planet. The day speeds up until it gets to be as brief as the month, or until the moon crashes into the planet.The remarkable thing is that, even though gravity is a conservative force, here the moon’s gravity acts non-conservatively on the planet, because the planet is constantly being deformed by the tide. The process that I’ve described (“tidal acceleration”) would be impossible without an internal mechanism of dissipation in the planet.

I know this is more detailed than usual, but I am fascinated in the continued mystery of this artifact. Almost 400 years after it's creation, no one truly knows how to decipher its text and illustrations. What follows is based on my research into the origins, authorship, hypotheses about the code/cipher, and what exactly the cider (cypher?) attempted to discuss. I've included either online links to published works and images or citations and added links to further explain terminology for those interested.For those interested in the details read on. For those who just want to know the generalizations, read the introduction and the last 5 paragraphs.CITATION OF IMAGE : WIKIMEDIA COMMONSSince its discovery in 1912, the 15th century Voynich Manuscript has been a mystery and a cult phenomenon. Full of handwriting in an unknown language or code, the book is heavily illustrated with weird pictures of alien plants, naked women, strange objects, and zodiac symbols. The script is comprised of roughly 25 to 30 individual characters (interpretations vary) written from left to right in a single, elegant hand. Scattered throughout are illustrations of unidentifiable plants, astrological diagrams, doodles of castles and dragons, and a particularly odd section that shows naked women bathing in pools connected by flowing tubes. It looks like the map of an ancient water park, but scholars suggest it might be medical or alchemical in intent.The manuscript is an illustrated codex hand-written in an unknown writing system. The vellum on which it is written has been carbon-dated to the early 15th century (1404–1438), and it may have been composed in Northern Italy during the Italian Renaissance. The earliest information about the existence comes from a letter that was found inside the covers of the manuscript, and it was written in either 1665 or 1666.No one has yet demonstrably deciphered the text, and it has become a famous case in the history of the cryptography. The mystery of the meaning and origin of the manuscript has excited the popular imagination, making the manuscript the subject of novels and speculation. None of the many hypotheses proposed over the last hundred years has yet been independently verified.The first confirmed owner was Georg Baresch, an obscure alchemist from Prague. Baresch was apparently just as puzzled as modern scientists about this " Sphynx" that had been "taking up space uselessly in his library" for many years. (For the history of ownership of the manuscript please refer to History of the MS and Voynich manuscript - Wikipedia ).A letter written on August 19, 1665 or 1666 was found inside the cover and accompanied the manuscript when Johannes Marcus sent it to Kircher (Zandbergen, René (May 19, 2016)."Voynich MS - 17th Century letters related to the MS". The Voynich Manuscript). It claims that the book once belonged to Emperor Rudolph II, who paid 600 gold ducats (about 2.07 kg of gold) for it. The letter was written in Latin and has been translated to English. The book was then given or lent to Jacobus Horcicky do Tepenecz, the head of Rudolph's botanical gardens in Prague, probably as part of the debt that Rudolph II owed upon his death.He learned that Jesuit scholar Athanasius Kircher from the Collegio Romano had published a Coptic ( Egyptian) dictionary an claimed that have deciphered the Egyptian hieroglyphs; Baresch twice sent a sample copy of the script to Kircher in Rome, asking for clues. His 1639 letter to Kircher is the earliest confirmed mention of the manuscript that has been found to date (Schuster, John (April 27, 2009). Haunting Museums. Tom Doherty Associates. pp. 175–272. ISBN 978-1-4299-5919-3).The manuscript then disappeared for 250 years, only to resurface when it was purchased by Polish book dealer Wilfrid Voynich in 1912. Voynich refused to divulge the manuscript’s previous owner, leading many to believe that he had authored the text himself. But after Voynich’s death, his wife claimed that he had purchased the book from the Jesuit College at Frascati near Rome.In 1903, the Society of Jesus (Collegio Romano) was short of money and decided to sell some of its holdings discreetly to the Vatican Library. The sale took place in 1912, but not all of the manuscripts listed for sale ended up going to the Vatican. Wilfrid Voynich acquired 30 of these manuscripts, among them the one which now bears his name.For the next section describing the physical and scientific characteristics of the manuscript, please refer to Voynich manuscript - Wikipedia and Beinecke Rare Book & Manuscript Library).The codicology, or physical characteristics of the manuscript, has been studied by numerous researchers and institutions. The manuscript measures 23.5 by 16.2 by 5 cm (9.3 by 6.4 by 2.0 in), with hundreds of vellum pages collected into 18 quires. The total number of pages is around 240, but the exact number depends on how the manuscript's unusual foldouts are counted.The quires have been numbered from 1 to 20 in various locations, using numerals consistent with the 1400s, and the top righthand corner of each recto (righthand) page has been numbered from 1 to 116, using numerals of a later date. From the various numbering gaps in the quires and pages, it seems likely that in the past the manuscript had at least 272 pages in 20 quires, some of which were already missing when Wilfrid Voynich acquired the manuscript in 1912. There is strong evidence that many of the book's bifolios were reordered at various points in its history, and that the original page order may well have been quite different from what it is today.Radiocarbon dating of samples from various parts of the manuscript was performed at the University of Arizona in 2009 (https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.voynich.nu/extra/carbon.html&ved=2ahUKEwjVnfiUoJXeAhVH64MKHQ_-CDMQFjAAegQIBBAB&usg=AOvVaw2ZfVBKgSiZY_BColPi-ACB) results were consistent for all samples tested and indicated a date for the parchment between 1404 and 1438.Protein testing in 2014 (Strong Notes http://PDFApprendre-en-ligne.net) that the parchment was made from calf skin, and multispectral analysis showed that it was unwritten on before the manuscript was created. The parchment was created with care, but deficiencies exist and the quality is assessed as average, at best. The goat skin binding and covers are not original to the book, but date to its possession by the Collegio Romano (Zandbergen, René (May 27, 2016."About the binding of the MS". The Voynich Manuscript).Insect holes are present on the first and last folios of the manuscript in the current order and suggest that a wooden cover was present before the later covers, and discolouring on the edges points to a tanned-leather inside cover.Many pages contain substantial drawings or charts which are colored with paint. Based on modern analysis using polarized light microscopy (PLM), it has been determined that a question pen and iron gall ink were used for the text and figure outlines; the colored paint was applied (somewhat crudely) to the figures, possibly at a later date. The ink of the drawings, text and page and quire numbers had similar microscopic characteristics. Energy-dispersive X-ray spectroscopy (EDS) performed in 2009 revealed that the inks contained major(http://PDFApprendre-en-ligne.net ›) of iron, sulfur, potassium, calcium and carbon and the amounts of copper and occasionally zinc. EDS did not show the presence of lead, while X-ray diffraction (XRD) identified potassium levels oxide, potassium hydrogen sulphate and syngenite in one of the samples tested. The similarity between the drawing inks and text inks suggested a contemporaneous origin.The blue, clear (or white), red-brown, and green paints of the manuscript have been analyzed using PLM, XRD, EDS, and scanning electron microscopy (SEM). The blue paint proved to be ground azurite with minor traces of the copper oxide cuprite. The clear paint is likely a mixture of eggwhite and calcium carbonate, while the green paint is tentatively characterized by copper and copper chlorineresinate; the crystalline material might be atacamite or another copper-chlorine compound. Analysis of the red-brown paint indicated a red ochre with the crystal phases hematite and iron sulfide. Minor amounts of lead sulfide and palmierite were possibly present in the red-brown paint. The pigments were considered inexpensive.CITATION OF IMAGE : WIKIMEDIA COMMONSThe first half of the book is filled with drawings of plants; scholars call this the “herbal” section. None of the plants appear to be real, although they are made from the usual stuff (green leaves, roots, and so on; search a word like “botanical” in the British Library’s illuminated-manuscript catalogue and you’ll find several texts that are similar to this part). The next section contains circular diagrams of the kind often found in medieval zodiacal texts; scholars call this part “astrological,” which is generous. Next, the so-called “balneological” section shows “nude ladies,” in Clemens’s words, in pools of liquid, which are connected to one another via a strange system of tubular plumbing that often snakes around whole pages of text. These scenes resemble drawings in the alchemical tradition, which gave rise to a now debunked theory that the thirteenth-century natural philosopher Roger Bacon wrote the book. Then we get what appear to be instructions in the practical use of those plants from the beginning of the book, followed by pages that look roughly like recipes.The drawings of different herbal plants are the most interesting thing that found on Vacation manuscript. Unfortunately, none of the 126 plant illustrations can be definitively identified. However, the plant pictures at least enabled certain conclusions regarding the date of origin, before the radiocarbon dating was performed. Until now no one can match these drawings to any known plant species. It is believed to be Voynich manuscript was written in 15th century. Apart from the herbal section, this mysterious manuscript also contains astronomical, biological, cosmological and pharmaceutical section.Every page in the manuscript contains text, mostly in an unidentified language, but some have extraneous writing in Latin script. The bulk of the text in the 240-page manuscript is written in an unknown script, running left to right. Most of the characters are composed of one or two simple pen strokes. Some dispute exists as to whether certain characters are distinct, but a script of 20–25 characters would account for virtually all of the text; the exceptions are a few dozen rarer characters that occur only once or twice each.The illustrations are conventionally used to divide most of the manuscript into six different sections, since the text itself cannot be read. Each section is typified by illustrations with different styles and supposed subject matter except for the last section, in which the only drawings are small stars in the margin. The following are the sections and their conventional names (Shailor, Barbara A. "Beinecke MS 408; Beinecke Rare Book And Manuscript Library, General Collection Of Rare Books And Manuscripts, Medieval And Renaissance Manuscripts):Herbal, 112 folios: Each page displays one or two plants and a few paragraphs of text, a format typical of European herbals of the time. Some parts of these drawings are larger and cleaner copies of sketches seen in the "pharmaceutical" section. None of the plants depicted are unambiguously identifiable.Astronomical, 21 folios: Contains circular diagrams suggestive of astronomy or astrology, some of them with suns, moons, and stars. One series of 12 diagrams depicts conventional symbols for the zodiacal constellations (two fish for Pisces, a bull for Taurus, a hunter with crossbow for Sagittarius, etc.). Each of these has 30 female figures arranged in two or more concentric bands. Most of the females are at least partly nude, and each holds what appears to be a labeled star or is shown with the star attached to either arm by what could be a tether or cord of some kind. The last two pages of this section were lost (Aquariusand Capricornus, roughly January and February), while Aries and Taurus are split into four paired diagrams with 15 women and 15 stars each. Some of these diagrams are on fold-out pages. Astrological considerations frequently played a prominent role in herb gathering, bloodletting, and other medical procedures common during the likeliest dates of the manuscript. However, interpretation remains speculative, apart from the obvious Zodiac symbols and one diagram possibly showing the classical planets.Pages from the astrological section of the Voynich manuscript (Beinecke Rare Book and Manuscript Library)Biological, 20 folios: A dense continuous text interspersed with figures, mostly showing small nude women, some wearing crowns, bathing in pools or tubs connected by an elaborate network of pipes. The bifolio consists of folios 78 (verso) and 81 (recto); it forms an integrated design, with water flowing from one folio to the other. The basins and tubes in the "biological" section are sometimes interpreted as implying a connection to alchemy, yet they bear little obvious resemblance to the alchemical equipment of the period.Cosmological, 13 folios: More circular diagrams, but they are of an obscure nature. This section also has foldouts; one of them spans six pages, commonly called the Rosettes folio, and contains a map or diagram with nine "islands" or "rosettes" connected by “causeways" and containing castles, as well as what might be a volcanoes.Pharmaceutical, 34 folios: Many labeled drawings of isolated plant parts (roots, leaves, etc.), objects resembling apothecary jars, ranging in style from the mundane to the fantastical, and a few text paragraphs.Recipes, 22 folios: Full pages of text broken into many short paragraphs, each marked with a star in the left margin.The overall impression given by the surviving leaves of the manuscript is that it was meant to serve as a pharmacopoeia or to address topics in medieval or early modern medicine. However, the puzzling details of illustrations have fueled many theories about the book's origin, the contents of its text, and the purpose for which it was intended.The first section of the book is almost certainly herbal, but attempts have failed to identify the plants, either with actual specimens or with the stylized drawings of contemporaneous herbals. Only a few of the plant drawings can be identified with reasonable certainty, such as a wild pansy and the maidenhair fern. The herbal pictures that match pharmacological sketches appear to be clean copies of them, except that missing parts were completed with improbable-looking details. In fact, many of the plant drawings in the herbal section seem to be composite: the roots of one species have been fastened to the leaves of another, with flowers from a third.In 2014, Arthur O. Tucker and Rexford H. Talbert published a paper claiming a positive identification of 37 plants, six animals, and one mineral referenced in the manuscript to plant drawings in the Libellus de Medicinalibus Indorum Herbis or Badianus manuscript, a fifteenth century Aztec herbal.(https://www.google.com/url?sa=t&source=web&rct=j&url=https://hydeandrugg.wordpress.com/2014/02/04/tucker-and-talbert-and-the-voynich-manuscript/amp/&ved=2ahUKEwj0yOyeoZXeAhUMyoMKHcbYC0AQFjABegQICBAB&usg=AOvVaw02Tn96aBEZ7MZzUTgdk5h7&ampcf=1) They argue that the plants were from Colonial New Spain and represented the Nahuatl language, and date the manuscript to between 1521 (the date of the Conquest) and circa 1576, in contradiction of radiocarbon dating evidence of the vellum and many other elements of the manuscript. However, the vellum, while creation of it was dated earlier, could just have been stored and used at a later date for manuscript making. The analysis has been criticized by other Voynich manuscript researchers, pointing out that—among other things—a skilled forger could construct plants that have a passing resemblance to theretofore undiscovered existing plants.Exhaustive scientific and conservational analysis of the parchment on which the manuscript is written, the stitching of the binding in which it is contained, and the inks and paints with which it was written and illuminated have disposed of the notion that the manuscript dates from the thirteenth century or that it is the work of Roger Bacon. Radio carbon dating of slivers from a range of pages has firmly dated the book’s materials to the years around 1430. The vellum pages are made of good-quality (and therefore expensive) calfskin, commonly used in book production all over medieval Europe. (Goatskin vellum, by contrast, would have strengthened the case for a southern German or Italian origin, a provenance favored by many students of the manuscript.)Many people have been proposed as possible authors of the Voynich manuscript, among them, Roger Bacon, John Dee or Edward Kelley, Giovanni Fontana, or Voynich himself. Please refer to The Voynich Manuscript, edited by Raymond Clemens Yale University Press 2016 and to Voynich manuscript - Wikipedia for summations of the proposed authorship of the manuscript.Marci's 1665/1666 (Jackson, David (January 23, 2015). "The Marci letter found inside the VM") cover letter to Kircher says that, according to his friend the late Raphael Mnishovsky, “the book had once been bought by Rudolf II How Roman Emperor and King of Bohemia for 600 ducats” (66.42 troy ounce actual gold weight, or 2.07 kg). (Mnishovsky had died in 1644, more than 20 years earlier, and the deal must have occurred before Rudolf's abdication in 1611, at least 55 years before Marci's letter. However, Karl Widemann sold books to Rudolf II in March 1599.)According to the letter, Mnishovsky (but not necessarily Rudolf) speculated that the author was 13th century Franciscan friar and polymath Roger Bacon. Marci said that he was suspending judgment about this claim, but it was taken quite seriously by Wilfrid Voynich who did his best to confirm it. Voynich (Here's What You Need to Know About the Mysterious Voynich Manuscript) contemplated the possibility that the author was Albertus Magnus if not Roger Bacon. The assumption that Bacon was the author led Voynich to conclude that John Dee sold the manuscript to Rudolf. Dee was a mathematician and astrologer at the court of Queen Elizabeth I of Englandwho was known to have owned a large collection of Bacon's manuscripts.Some suspect Voynich of having fabricated the manuscript himself. As an antique book dealer, he probably had the necessary knowledge and means, and a lost book by Roger Bacon would have been worth a fortune. Furthermore, Baresch's letter and Marci's letter only establish the existence of a manuscript, not that the Voynich manuscript is the same one mentioned. These letters could possibly have been the motivation for Voynich to fabricate the manuscript, assuming that he was aware of them. However, many consider the expert internal dating of the manuscript and the June 1999 discovery of Baresch's letter to Kircher as having eliminated this possibility.It has been suggested that some illustrations in the books оf an Italian engineer, Giovanni Fontana, slightly resemble Voynich illustrations (Has the Enigmatic Voynich Manuscript Code Finally Been Cracked?). Fontana was familiar with cryptography and used it in his books, although he didn't use the Voynich script but a simple substitution cipher. In the book Secretum de thesauro experimentorum ymaginationis hominum (Secret of the treasure-room of experiments in man's imagination), written c. 1430, Fontana described mnemonic machines, written in his cypher. At least Bellicorum instrumentorum liber and this book used a cryptographic system, described as a simple, rational cipher, based on signs without letters or numbers.Baresch's letter bears some resemblance to a hoax that orientalist Andreas Mueller once played on Kircher (Athanasius Kircher, Victim of Pranks). Mueller sent some unintelligible text to Kircher with a note explaining that it had come from Egypt, and asking him for a translation. Kircher reportedly solved it. It has been speculated that these were both cryptographic tricks played on Kircher to make him look foolish.Raphael Mnishovsky, the friend of Marci who was the reputed source of Bacon's story, was himself a cryptographer and apparently invented a cipher which he claimed was uncrackable (c. 1618). This has led to the speculation that Mnishovsky might have produced the Voynich manuscript as a practical demonstration of his cipher and made Baresch his unwitting test subject (No, the Mysterious Voynich Manuscript Is Not Written in Hebrew). Indeed, the disclaimer in the Voynich manuscript cover letter could mean that Marci suspected some kind of deception.In 2006, Nick Pelling (Pelling, Nicholas John (2006). The Curse of the Voynich: The Secret History of the World's Most Mysterious Manuscript. Compelling Press), proposed that the Voynich manuscript was written by 15th century North Italian architect Antonio Averlino (also known as "Filarete"), a theory broadly consistent with the radiocarbon dating.The Voynich manuscript has been studied by many professional and amateur cryptographers, including American and British codebreakers from both World Wars I and II. Most assume that the manuscript is written in what’s called a substitution cipher (Substitution cipher - Wikipedia). This is one of the simplest and most ancient types of codes, in which letters of an established alphabet are swapped for invented ones. The problem is that hundreds of years of study have been unable to work out which language the Voynich manuscript was originally written in.According to the "letter-based cipher" theory, the Voynich manuscript contains a meaningful text in some European language that was intentionally rendered obscure by mapping it to the Voynich manuscript "alphabet" through a cipher of some sort—an algorithm that operated on individual letters. This was the working hypothesis for most 20th-century deciphering attempts, including an informal team of NSA cryptographers led by William F. Friedman in the early 1950s. (Reeds, Jim (September 7, 1994). "William F. Friedman's Transcription of the Voynich Manuscript" (PDF). AT&T Bell Laboratories. pp. 1–23). The main argument for this theory is that it is difficult to explain a European author using a strange alphabet—except as an attempt to hide information. Indeed, even Roger Bacon knew about ciphers, and the estimated date for the manuscript roughly coincides with the birth of cryptography in Europe as a relatively systematic discipline.The counterargument is that almost all cipher systems consistent with that era fail to match what is seen in the Voynich manuscript. For example, simple substitution ciphers would be excluded because the distribution of letter frequencies does not resemble that of any known language; while the small number of different letter shapes used implies that nomenclator and homophonic ciphers would be ruled out, because these typically employ larger cipher alphabets. Please ciphers (Alberti cipher - Wikipedia) were invented by Alberti in the 1460s and included the later Vigenère cipher, but they usually yield ciphertexts where all cipher shapes occur with roughly equal probability, quite unlike the language-like letter distribution which the Voynich manuscript appears to have.According to the "codebook cipher" theory (Languedoc Mysteries), the Voynich manuscript "words" would actually be codes to be looked up in a "dictionary" or codebook. The main evidence for this theory is that the internal structure and length distribution of many words are similar to those of Roman numerals, which at the time would be a natural choice for the codes. However, book-based ciphers would be viable for only short messages, because they are very cumbersome to write and to read.That the encryption system started from a fundamentally simple cipher and then augmented it by adding nulls (meaningless symbols), homophones (duplicate symbols), transposition cipher (letter rearrangement), false word breaks, and more is also entirely possible.Steganography (Steganography - Wikipedia) that the text of the Voynich manuscript is mostly meaningless, but contains meaningful information hidden in inconspicuous details—e.g., the second letter of every word, or the number of letters in each line. This technique, is very old and was described by Johannes Trithemius in 1499. Though the plain text was speculated to have been extracted by a Cardan grille (an overlay with cut-outs for the meaningful text Cardan grille - Wikipedia) of some sort, this seems somewhat unlikely because the words and letters are not arranged on anything like a regular grid. Still, steganographic claims are hard to prove or disprove, since stegotexts can be arbitrarily hard to find.It has been suggested that the meaningful text could be encoded in the length or shape of certain pen strokes. There are indeed examples of steganography from about that time that use letter shape (italic vs. upright) to hide information. However, when examined at high magnification, the Voynich manuscript pen strokes seem quite natural, and substantially affected by the uneven surface of the vellum.Linguist Jacques Guy once suggested that the Voynich manuscript text could be some little-known natural language, written in the the plain with an invented alphabet. The word structure is similar to that of many language families of East and Central Asia, mainly Sino-Tibetan (Chinese, Tibetan, and Burmese), Austroasiatic (Vietnamese, Khmer, etc.) and possibly Tai ( Thai, Lao, etc.). In many of these languages, the words have only one syllable; and syllables have a rather rich structure, including the patterns. (Lev Grossman, "When Words Fail: The Struggle to Decipher the World's Most Difficult Book", Lingua franca, April 1999).This theory has some historical plausibility. While those languages generally had native scripts, these were notoriously difficult for Western visitors. This difficulty motivated the invention of several phonetic scripts, mostly with Local letters, but sometimes with invented alphabets. Although the known examples are much later than the Voynich manuscript, history records hundreds of explorers and missionaries who could have done it—even before Marco Polo's 13th-century journey, but especially after Visiting do Gama sailed the sea route to the Orient in 1499.The first page includes two large red symbols, which have been compared to a Chinese-style book title. (Chinese Sinograms in the Voynich THE VOYNICH MANUSCRIPT)The main argument for this theory is that it is consistent with all statistical properties of the Voynich manuscript text which have been tested so far, including doubled and tripled words (which have been found to occur in Chinese and Vietnamese texts at roughly the same frequency as in the Voynich manuscript) (Voynich: the evidence).It also explains the apparent lack of numerals and Western syntactic features (such as articles and copulas), and the general inscrutability of the illustrations. Another possible hint is two large red symbols on the first page, which have been compared to a Chinese-style book title, inverted and badly copied. Also, the apparent division of the year into 360 days (rather than 365 days), in groups of 15 and starting with Pisces, are features of the Chinese agricultural calendar(jie qi, 節氣). The main argument against the theory is the fact that no one (including scholars at the Chinese Academy of Sciences in Beijing) has been able to find any clear examples of Asian symbolism or Asian science in the illustrations.In 1976, James R Child, a linguist of Indo-European languages, proposed that the manuscript was written in a "hitherto unknown North Germanic dialect" (The Voynich Manuscript Revisited'). He identified in the manuscript a "skeletal syntax several elements of which are reminiscent of certain Germanic languages", while the content itself is expressed using "a great deal of obscurity".Leo Levitov proposed in his 1987 book, (Solution of the Voynich Manuscript: A Liturgical Manual for the Endura Rite of the Cathari Heresy, the Cult of Isis), that the manuscript is a handbook for the Cathar rite of Endura written in a Flemish based creole. He further claimed that Catharism was descended from the cult of Isis. However, Levitov's decipherment has been refuted on several grounds, not least of which is its being unhistorical. Levitov had a poor grasp on the history of the Cathars, and his depiction of Endura as an elaborate suicide ritual is at odds with surviving documents describing it as a fast. Likewise there is no known link between Catharism and Isis.In February 2014, Professor Stephen Bax of the University of Bedfordshire made public his research into using "bottom up" methodology to understand the manuscript (Voynich: the evidence). His method involves looking for and translating proper nouns, in association with relevant illustrations, in the context of other languages of the same time period. A paper he posted online offers tentative translation of 14 characters and 10 words. He suggests the text is a treatise on nature written in a natural language, rather than a code.In 2014, a team led by Dr. Diego Amancio of the University of São Paulo's Institute of Mathematical and Computer Sciences published a paper detailing a study using statistical methods to analyse the relationships of the words in the text (Probing the statistical properties of unknown texts: application to the Voynich Manuscript. Amancio DR, et al. PLoS One. 2013).Instead of trying to find the meaning, Amancio's team used complex network modelling to look for connections and clusters of words. By employing concepts such as frequency and intermittence, which measure occurrence and concentration of a term in the text, Amancio was able to discover the manuscript's keywords and create three-dimensional models of the text's structure and word frequencies. Their conclusion was that in 90% of cases, the Voynich systems are similar to those of other known books such as the Bible, indicating that the book is an actual piece of text in an actual language, and not well-planned gibberish.The unusual features of the Voynich manuscript text (such as the doubled and tripled words), and the suspicious contents of its illustrations support the idea that the manuscript is a hoax. In other words, if no one is able to extract meaning from the book, then perhaps this is because the document contains no meaningful content in the first place. Various hoax theories have been proposed over time.In 2003, computer scientist Gordon Rugg showed that text with characteristics similar to the Voynich manuscript could have been produced using a table of word prefixes, stems, and suffixes, which would have been selected and combined by means of a perforated paper overlay (https://doi.org/10.1080/0161-110491892755).The latter device, known as a Cardan grille (Cardan grille - Wikipedia) was invented around 1550 as an encryption tool, more than 100 years after the estimated creation date of the Voynich manuscript. Some maintain that the similarity between the pseudo-texts generated in Gordon Rugg's experiments and the Voynich manuscript is superficial, and the grille method could be used to emulate any language to a certain degree.In April 2007, a study by Austrian researcher Andreas Schinner published in Cryptologia supported the hoax hypothesis (https://doi.org/10.1080/01611190601133539). Schinner showed that the statistical properties of the manuscript's text were more consistent with meaningless gibberish produced using a quasi stochastic method such as the one described by Rugg, than with Latin and medieval German texts.Some scholars have claimed that the manuscript's text appears too sophisticated to be a hoax. In 2013 Marcelo Montemurro, a theoretical physicist from the University of Manchester, (Keywords and Co-Occurrence Patterns in the Voynich Manuscript: An Information-Theoretic Analysis), published findings claiming that semantic networks exist in the text of the manuscript, such as content-bearing words occurring in a clustered pattern, or new words being used when there was a shift in topic.With this evidence, he believes it unlikely that these features were intentionally "incorporated" into the text to make a hoax more realistic, as most of the required academic knowledge of these structures did not exist at the time the Voynich manuscript would have been written.(Alphabet by Hildegard von Bingen, Litterae ignotae, which she used for her language Lingua Ignota)Detail of the "nymphs" on page 141; f78r CITATION OF IMAGE : WIKIMEDIA COMMONSIn their 2004 book, Gerry Kennedy and Rob Churchill suggest the possibility that the Voynich manuscript may be a case of glossolalia (speaking-in-tongues), channeling, or outsider art. If so, the author felt compelled to write large amounts of text in a manner which resembles stream of consciousness, either because of voices heard or because of an urge. This often takes place in an invented language in glossolalia, usually made up of fragments of the author's own language, although invented scripts for this purpose are rare.Kennedy and Churchill (The Voynich Manuscript: The Unsolved Riddle of an Extraordinary Book Which has Defied Interpretation for Centuries 2004) use Hildegard von Bingen's works to point out similarities between the Voynich manuscript and the illustrations that she drew when she was suffering from severe bouts of migraine, which can induce a trance-like state prone to glossolalia. Prominent features found in both are abundant "streams of stars", and the repetitive nature of the nymphs in the biological section.This theory has been found unlikely by other researchers. The theory is virtually impossible to prove or disprove, short of deciphering the text. Kennedy and Churchill are themselves not convinced of the hypothesis, but consider it plausible. In the culminating chapter of their work, Kennedy states his belief that it is a hoax or forgery. Churchill acknowledges the possibility that the manuscript is a synthetic forgotten language (as advanced by Friedman) or a forgery as preeminent theories. However, he concludes that, if the manuscript is genuine, mental illness or delusion seems to have affected the author.In 2014, expert in applied linguistics Professor Stephen Bax published an article in which he claimed to have translated ten words from the manuscript using techniques similar to those used to successfully translate Egyptian hieroglyphs. He claimed the manuscript to be a treatise on nature, in a Near Eastern or Asian language, but no full translation was made before his death in 2017.Recently, history researcher and television writer Nicholas Gibbs (Voynich manuscript: the solution) have cracked the code, discovering that the book is actually a guide to women's health that's mostly plagiarized from other guides of the era.Gibbs realized he was seeing a common form of medieval Latin abbreviations, often used in medical treatises about herbs. "From the herbarium incorporated into the Voynich manuscript, a standard pattern of abbreviations and ligatures emerged from each plant entry," he wrote. "The abbreviations correspond to the standard pattern of words used in the Herbarium Apuleius Platonicus – aq = aqua (water), dq = decoque / decoctio (decoction), con = confundo (mix), ris = radacis / radix (root), s aiij = seminis ana iij (3 grains each), etc." So this wasn't a code at all; it was just shorthand. The text would have been very familiar to anyone at the time who was interested in medicine.The mysterious medieval Voynich Manuscript is probably a women's health manual, according to history researcher Nicholas Gibbs.Once he realized that the Voynich Manuscript was a medical textbook, Gibbs explained, it helped him understand the odd images in it. Pictures of plants referred to herbal medicines, and all the images of bathing women marked it out as a gynecological manual. Baths were often prescribed as medicine, and the Romans were particularly fond of the idea that a nice dip could cure all ills. Zodiac maps were included because ancient and medieval doctors believed that certain cures worked better under specific astrological signs. Gibbs even identified one image—copied, of course, from another manuscript—of women holding donut-shaped magnets in baths. Even back then, people believed in the pseudoscience of magnets.As soon as Gibbs' article hit the Internet, news about it spread rapidly through social media, arousing the skepticism of cipher geeks and scholars alike. Unfortunately, say experts, his analysis was a mix of stuff we already knew and stuff he couldn't possibly prove.So where does that leave us with our understanding of the Voynich Manuscript? Exhaustive scientific and conservational analysis of the parchment on which the manuscript is written, the stitching of the binding in which it is contained, and the inks and paints with which it was written and illuminated have disposed of the notion that the manuscript dates from the thirteenth century or that it is the work of Roger Bacon. Radio carbon dating of slivers from a range of pages has firmly dated the book’s materials to the years around 1430. The vellum pages are made of good-quality (and therefore expensive) calfskin, commonly used in book production all over medieval Europe. (Goatskin vellum, by contrast, would have strengthened the case for a southern German or Italian origin, a provenance favored by many students of the manuscript.)Equally, all this effectively rules out any possibility that the manuscript is a post-medieval forgery—it is inconceivable that the huge quantities of blank parchment needed for such a forgery could have survived from the early fifteenth century. The book’s pages, whose consistency suggests that they derived from a single source, would have required at least fourteen or fifteen entire calfskins. It is therefore overwhelmingly likely that the manuscript was written and illustrated soon after the parchment was prepared, in the first third of the fifteenth century. Its fluent cursive handwriting, without emendation of any kind, seems incompatible with the notion that it might nevertheless be a careful scribal copy of an earlier medieval text. The dating of its materials to the early fifteenth century rules out the suggestion, credited by art historians like Erwin Panofsky, but never very convincing, that the manuscript contains illustrations of plants such as capsicum or the sunflower, unknown before the discovery of the New World.The manuscript was probably composed of 100s of texts, notes, observations and illustrations related to aspects of women's health during the Midieval and Rennassance periods, along with a little alchemical knowledge. In all likelihood, women did not constitute the intended audience, rather it would have been directed towards herbalists, alchemists, philosphers and pharmicists. But from the start, the known evidence suggests that the manuscript was only known by a select group of scholars and royality, experiencing a cyclical pattern of a few years in the spotlight, followed by centuries of relative anonmyity in secret collections and libraries.

I’ve been studying the flat-earth “phenomenon” for a couple of years now (on YouTube and FaceBook). If I were you, I would carefully check the credentials of the flat-earth proponents before declaring them “well educated.” I find that they’re good at copying and pasting, and some are talented at making videos, but they are generally severely lacking in very basic knowledge of math and science (and in many cases are arrogantly anti-scientific and rebuke mathematical analysis).As for my own credentials: I have a B.S. degree in physics; have worked 11 years as an aerospace engineer; and have been an amateur astronomer for 40+ years (I currently work as a volunteer at the Hyde Observatory in Lincoln, NE). I have always questioned what my schoolteachers told me; which is exactly what drove me to research and experiment and learn as much science as I could.The flat-earth model fails in countless ways; I’ll detail just a few.The flat-earth model posits that the celestial bodies are all located only a few thousand miles above the earth, possibly on a dome-shaped “firmament.” But that hypothesis has geometrical consequences that don’t fit with observations. For example: Imagine there are two widely separated observers who are both simultaneously looking at the same pair of stars in the sky, as in this diagram:The observer on the left sees that the stars are separated by an angle “θ₁”, while the other, many miles away, sees them separated by an angle “θ₂”. As you can probably see (or you can measure with a protractor), these two angles are notably different; this variance in angular separation is a direct result of the stars being relatively close to earth, compared to the observers’ separation.But the problem is, in real life, we never, ever observe any variation between θ₁ and θ₂, no matter which stars we choose, and no matter where we position the observers on the earth. Any given pair of stars (say, Castor and Pollux), has its own unique angular separation (in this case, 4.506 degrees), that remains the same regardless of where on earth they’re observed from.This real-life observation is not possible in the geometry of a nearby dome firmament. It’s only possible if all the stars are EXTREMELY distant, compared to the size of the earth.Which means, if the earth really is flat, the real situation must look something more like this:Except that this isn’t really to scale, because the earth would have to be much, much smaller than this, compared to the stars’ distance, if it’s to match with our observations about the stars’ angular separations as described above. Imagine a little green line, say, 1/1000 of an inch long.But that’s a problem for the flat earth. Why? Pick out a star in the above diagram — say the red one —and let’s think about various people on the flat earth, simultaneously looking up at that red star. Now that we know the whole earth is positively minuscule compared to the distance to the stars, it is evident that observers all over the flat earth, when they look up at the red star, will have to point their telescopes at exactly the same angle to see it.But the thing is, they don’t. In real life, if one astronomer is pointing his telescope at 40 degrees elevation to see the star, then if you travel 690 miles away you’ll find another astronomer pointing up at 50 degrees to see the same star. Another 690 miles away, the star will be at 60 degrees elevation; and so on.Considering the stars’ great distance, we cannot explain this as just a “shift of perspective,” as flat-earthers usually do (technically, a “translation transformation”). Geometrically, this observed shift in pointing angle is only possible if the observers are actually oriented differently with respect to one another. In other words, one observer’s vertical is not parallel to another observer’s vertical. In other words, the surface of the planet they’re standing on is CURVED.This is more or less the reasoning that Aristotle used to argue for a globe earth, and it’s been refined with more precise measurements in the intervening centuries. Flat-earthers simply side-step this whole issue. If it’s brought up, they’ll just bleat the word “perspective” without any real understanding of the geometrical theory behind it; and if you try to back up your argument with real equations and actual measurements, they’ll babble about how “math is meaningless.”Another claim that flat-earthers are fond of making is that “the horizon always rises to eye level, no matter how high you go.” The idea, of course, is that the horizon ought to drop down below your eye level as you rise, if we truly live on a globe.But does the horizon really rise to eye level? Amazingly, no flat-earther has ever offered a shred of experimental evidence to back up that claim. I think they simply assume (wrongly) that the horizon ought to drop dramatically on an earth-sized globe. But (as predicted by globe math) it actually only drops a little, and I think flat-earthers just believe (without measuring) that that small drop is “eye level.”In stark contrast, thousands of people (amateurs and professionals) actually have measured the drop of the horizon below eye level, for at least 1,000 years, going back to the famous experiments of Abu al Biruni — there are a number of simple techniques to do it — and they invariably find that the results are consistent with an 8,000-mile diameter globe. I’ve done it myself:When I took this photo, I carefully aligned the camera lens with the stitching at the top of the seat back in the row ahead of me, to get a good eye-level reference (you can see where the “eye level” line aligns with the stitching if you enlarge the photo).I measured the distance from the camera to the window to be about 58 inches. I measured the distance from the “eye level” line to the horizon line to be about 3.4 inches. That allowed me to calculate an angle for the horizon drop:angle = arctan(3.4 inches/58 inches) = 3.21°How did that compare with prediction? The pilot said we were flying at 33,000 feet. The predicted drop of the horizon at an altitude “h” is: [math]\tan^{-1}\sqrt{2h/R}[/math], where “R” is the earth’s radius. Plugging in the numbers, that gives an expected dip of 3.35°So that means my measurement was off by only about 4% from the predicted value for a globe earth. So much for the horizon “always rising to eye level.”The general impression I get from radical flat-earthers is that they “accepted” the globe model as kids, but never felt comfortable with it. And instead of badgering their teachers for a fuller understanding (like I did), they just “went with the flow,” and lived with their doubts, in a shared ignorance that has now exploded all over the Internet. My own feeling, from reading many of their comments and watching many of their videos, and reading between the lines, is that they may have spent years feeling slightly stupid and ashamed because they didn't “get” the round-earth idea, and how gravity works, and so on; and that the “FE revolution” now makes them feel, finally, that they were right all along, and that everybody else was stupid. So they cling to this idea. A self-esteem booster like that can be pretty intoxicating, and can make you impervious to new knowledge. You have to have the courage and humility to embrace your own ignorance, if you are really interested in seeking the truth.