In the ancient Mediterranean world , the classical compass winds were names for the points of geographic direction and orientation, in association with the winds as conceived of by the ancient Greeks and Romans . Ancient wind roses typically had twelve winds and thus twelve points of orientation, sometimes reduced to eight or increased to twenty-four.
165-477: Originally conceived as a branch of meteorology , the classical wind rose had only a tentative relationship with actual navigation . The Classical 12-point wind rose was eventually displaced by the modern compass rose (8-point, 16-point and 32-point), adopted by seafarers during the Middle Ages . It is uncertain when or why the human sense of geographic orientation and direction became associated with winds . It
330-632: A GPS clock for data logging . Upper air data are of crucial importance for weather forecasting. The most widely used technique is launches of radiosondes . Supplementing the radiosondes a network of aircraft collection is organized by the World Meteorological Organization . Remote sensing , as used in meteorology, is the concept of collecting data from remote weather events and subsequently producing weather information. The common types of remote sensing are Radar , Lidar , and satellites (or photogrammetry ). Each collects data about
495-633: A meridian drawn between the north ( arctos ) and its opposite could be used to divide East from West. Homer already spoke of Greeks sailing with Ursa Major (or "Wagon"/"Wain") for orientation. The identification of the Pole Star (at that time, Kochab in the Ursa Minor ) as the better indicator of the North seems to have emerged a little later (it is said Thales introduced this, probably learned from Phoenician seafarers). Distinct from these cardinal points,
660-551: A "fighting together", with the Lydians. This has sometimes been interpreted as an alliance. Croesus was defeated before the city of Sardis by Cyrus the Great , who subsequently spared Miletus because it had taken no action. Cyrus was so impressed by Croesus’ wisdom and his connection with the sages that he spared him and took his advice on various matters. The Ionian cities should be demoi, or "districts". He counselled them to establish
825-469: A Greek. Diogenes continues, by delivering more conflicting reports: one that Thales married and either fathered a son (Cybisthus or Cybisthon) or adopted his nephew of the same name; the second that he never married, telling his mother as a young man that it was too early to marry, and as an older man that it was too late. Plutarch had earlier told this version: Solon visited Thales and asked him why he remained single; Thales answered that he did not like
990-606: A Problem in Mechanics and Physics that it should be possible to forecast weather from calculations based upon natural laws . It was not until later in the 20th century that advances in the understanding of atmospheric physics led to the foundation of modern numerical weather prediction . In 1922, Lewis Fry Richardson published "Weather Prediction By Numerical Process," after finding notes and derivations he worked on as an ambulance driver in World War I. He described how small terms in
1155-498: A Roman geographer, formalized the climatic zone system. In 63–64 AD, Seneca wrote Naturales quaestiones . It was a compilation and synthesis of ancient Greek theories. However, theology was of foremost importance to Seneca, and he believed that phenomena such as lightning were tied to fate. The second book(chapter) of Pliny 's Natural History covers meteorology. He states that more than twenty ancient Greek authors studied meteorology. He did not make any personal contributions, and
1320-460: A collective of north winds, the Boreae . It is said that the geographer Eratosthenes of Cyrene (c. 200 BCE), realizing that many winds presented only slight variations, reduced twelve winds down to eight principal winds. Eratosthenes's own work has been lost, but the story is reported by Vitruvius , who goes on to say Eratosthenes came to this conclusion in the course of measuring the circumference of
1485-595: A coupled ocean-atmosphere system. Meteorology has application in many diverse fields such as the military, energy production, transport, agriculture, and construction. The word meteorology is from the Ancient Greek μετέωρος metéōros ( meteor ) and -λογία -logia ( -(o)logy ), meaning "the study of things high in the air". Early attempts at predicting weather were often related to prophecy and divining , and were sometimes based on astrological ideas. Ancient religions believed meteorological phenomena to be under
1650-466: A farmer's potential harvest. In 1450, Leone Battista Alberti developed a swinging-plate anemometer , and was known as the first anemometer . In 1607, Galileo Galilei constructed a thermoscope . In 1611, Johannes Kepler wrote the first scientific treatise on snow crystals: "Strena Seu de Nive Sexangula (A New Year's Gift of Hexagonal Snow)." In 1643, Evangelista Torricelli invented the mercury barometer . In 1662, Sir Christopher Wren invented
1815-485: A gale was expected. FitzRoy coined the term "weather forecast" and tried to separate scientific approaches from prophetic ones. Over the next 50 years, many countries established national meteorological services. The India Meteorological Department (1875) was established to follow tropical cyclone and monsoon . The Finnish Meteorological Central Office (1881) was formed from part of Magnetic Observatory of Helsinki University . Japan's Tokyo Meteorological Observatory,
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#17328416380241980-621: A group of meteorologists in Norway led by Vilhelm Bjerknes developed the Norwegian cyclone model that explains the generation, intensification and ultimate decay (the life cycle) of mid-latitude cyclones , and introduced the idea of fronts , that is, sharply defined boundaries between air masses . The group included Carl-Gustaf Rossby (who was the first to explain the large scale atmospheric flow in terms of fluid dynamics ), Tor Bergeron (who first determined how rain forms) and Jacob Bjerknes . In
2145-606: A later chapter, Pliny goes on to say that Aquilo, in the summer, turns into the Etesian winds, the periodic wind already referred to by Aristotle. Pliny also mentions, for the other half-winds, Phoenicias (for SSE, not Euronotus), Libonotus (SSW), and Thrascias (NNW). It is apparent Pliny had recently read Aristotle and sought to resurrect some of the abandoned Aristotelean names (Boreas/Aparctias, Meses, Etesian winds, Phoenicias, he even mentions Olympias and Sciron as local Greek winds), albeit they appear rather awkwardly when inserted into
2310-629: A later note that "Caecias" is mentioned in Aristotle (but does not give it a position). Aquilo/Boreas seem well-enthroned at NE. Another surprise is the re-emergence of Eurus in the East, where it has not been seen since Homer. He seems to treat Eurus as a Latin name, giving the Aristotelean Apeliotes as the Greek equivalent, and reducing Subsolanus to a mere variant "from Roman sailors". With Eurus now absent in
2475-473: A legitimate branch of physics. In the 18th century, the invention of the thermometer and barometer allowed for more accurate measurements of temperature and pressure, leading to a better understanding of atmospheric processes. This century also saw the birth of the first meteorological society, the Societas Meteorologica Palatina in 1780. In the 19th century, advances in technology such as
2640-496: A northwest wind and a southwest wind. Some have taken this to imply that Homer may have had as many as eight winds. However, others remain unconvinced, and insist Homer only had a four wind-rose. Writing several centuries later, Strabo (c. 10 BC) notes that some contemporaries took Homer's ambiguity to imply that the Homeric system may already anticipate the summer and winter distinction later made famous by Aristotle . This refers to
2805-492: A period up to a year. His system was based on dividing the year by the setting and the rising of the Pleiad, halves into solstices and equinoxes, and the continuity of the weather for those periods. He also divided months into the new moon, fourth day, eighth day and full moon, in likelihood of a change in the weather occurring. The day was divided into sunrise, mid-morning, noon, mid-afternoon and sunset, with corresponding divisions of
2970-662: A reference to Mount Olympus and the Sciros rocks in Megara . The remaining winds also seem to be geographical. Caecias ( καικίας ) means from Caicus, a river in Mysia , a region northeast of the Aegean. Lips ( λίψ ) means "from Libya ", to the southwest of Greece (although an alternative theory connects it to "leibo", λείβω , same root as libation , meaning pouring, because this wind brought rain). Phoenicias ( φοινικίας ) comes "from Phoenicia " (to
3135-599: A reference to the Mistral ) He also notes Iapyx (already mentioned, but first here explained as a local wind from Iapygia in Apulia ) and periodic regional Etesian winds and the "Prodromi" (NW fore-winds, in Greek, πρόδρομοι ). The "Vatican table" is a marble Roman anemoscope (wind-vane) dating from the 2nd or 3rd Century CE, held by the Vatican Museums . Divided into twelve equal sides, on each of its sides, it has inscribed
3300-483: A reference to the warm rains and storms brought from the south). Eurus and Zephyrus seem to come from "brightness" (q.v. Eos ) and "gloominess" ("zophos") respectively, doubtlessly a reference to sunrise and sunset . The archaic Greek poet Homer (c. 800 BC) refers to the four winds by name – Boreas, Eurus, Notos, Zephyrus – in his Odyssey , and in the Iliad . However, at some points, Homer seems to imply two more:
3465-485: A significant step in the evolution of the compass rose. Depending on how Ventorum Situs is dated, Timosthenes can be credited with turning Aristotle's asymmetric ten-wind compass into a symmetric twelve-wind compass, by introducing the SSW wind (Leuconotos/Libonotos) omitted by Aristotle and Theophrastus and assigning the compound "Euronotos" (already alluded to by Aristotle, no mention of Theophrastus's Orthonotos here) in place of
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#17328416380243630-595: A single seat of government, and pointed out Teos as the fittest place for it; "for that," he said, "was the centre of Ionia . Their other cities might still continue to enjoy their own laws, just as if they were independent states." Miletus, however, received favorable terms from Cyrus. The others remained in an Ionian League of twelve cities (excluding Miletus), and were subjugated by the Persians. Early Greeks, and other civilizations before them, often invoked idiosyncratic explanations of natural phenomena with reference to
3795-950: A snapshot of a variety of weather conditions at one single location and are usually at a weather station , a ship or a weather buoy . The measurements taken at a weather station can include any number of atmospheric observables. Usually, temperature, pressure , wind measurements, and humidity are the variables that are measured by a thermometer, barometer, anemometer, and hygrometer, respectively. Professional stations may also include air quality sensors ( carbon monoxide , carbon dioxide , methane , ozone , dust , and smoke ), ceilometer (cloud ceiling), falling precipitation sensor, flood sensor , lightning sensor , microphone ( explosions , sonic booms , thunder ), pyranometer / pyrheliometer / spectroradiometer (IR/Vis/UV photodiodes ), rain gauge / snow gauge , scintillation counter ( background radiation , fallout , radon ), seismometer ( earthquakes and tremors), transmissometer (visibility), and
3960-431: Is marine weather forecasting as it relates to maritime and coastal safety, in which weather effects also include atmospheric interactions with large bodies of water. Meteorological phenomena are observable weather events that are explained by the science of meteorology. Meteorological phenomena are described and quantified by the variables of Earth's atmosphere: temperature, air pressure, water vapour , mass flow , and
4125-489: Is about an angle intercepted by two parallel lines, forming a pair of similar triangles . Modern scholars are skeptical that anyone in Thales's time was producing mathematical proofs to the standard of later Greek mathematics, though not enough direct evidence remains to draw firm conclusions. While Thales may have discovered some basic geometric relations and provided some justification for them, attribution to him of formal proofs
4290-485: Is all we have, Diogenes wrote some eight centuries after Thales's death and his sources often contained "unreliable or even fabricated information". It is known Thales was from Miletus , a mercantile city settled at the mouth of the Maeander river . The dates of Thales's life are not exactly known, but are roughly established by a few datable events mentioned in the sources. According to the historian Herodotus , writing in
4455-531: Is already in Timosthenes, but Aparctias's demotion from the N is novel). When he goes on to discuss half-winds, Pliny re-introduces Caecis as lying "between Aquilo and Subsolanus", thus restoring it effectively to its NE position. Evidently reading Aristotle, Pliny tries to insert long-lost Meses again "between Boreas (= Aquilo) and Caecis", thus placing Meses in a position that (in a modern 32-point compass) would be called " Northeast by north ". Confusing matters, in
4620-412: Is also possible that he was of mixed ancestry, given his father had a Carian name and his mother had a Greek name. Diogenes Laërtius seems to also reference an alternative account: "Most writers, however, represent him as a genuine Milesian and of a distinguished family". Encyclopedia Britannica (1952) concluded that Thales was most likely a native Milesian of noble birth and that he was certainly
4785-598: Is also responsible for twilight in Opticae thesaurus ; he estimated that twilight begins when the sun is 19 degrees below the horizon , and also used a geometric determination based on this to estimate the maximum possible height of the Earth's atmosphere as 52,000 passim (about 49 miles, or 79 km). Adelard of Bath was one of the early translators of the classics. He also discussed meteorological topics in his Quaestiones naturales . He thought dense air produced propulsion in
4950-565: Is an attempt to derive the etymology of the winds. As they are often named after a particular locality from where they seem to blow, different places in the Hellenistic world have come up with variant local names for the winds. In the list given in the Ventorum Situs : The Greek-Roman physician Agathemerus (c. 250 CE), in his Geographia , gives the eight principal winds. But Agathemerus goes on to note that nearly five hundred years earlier,
5115-426: Is asymmetric. Specifically, the half-winds would be at 22½° on either side of the North, while the principal eight would be at 45° angles from each other. However, an alternative hypothesis is that they will be more equally spaced around 30° from each other. By way of guidance, Aristotle mentions that the easterly and westerly positions are that of the sun as seen on the horizon at dawn and at dusk at different times of
Classical compass winds - Misplaced Pages Continue
5280-583: Is believed the Babylonians knew the theorem for special cases. The theorem is mentioned and proved as part of the 31st proposition in the third book of Euclid 's Elements . Dante's Paradiso refers to Thales's theorem in the course of a speech. The story is told in Diogenes Laërtius , Pliny the Elder , and Plutarch , sourced from Hieronymus of Rhodes , that when Thales visited Egypt , he measured
5445-454: Is both "applied to those whose boasts exceed what they are" and "a warning to pay no attention to the opinion of the multitude." Diogenes Laërtius relates several stories of an expensive, gold tripod or bowl that is to go to the most wise . In one version (that Laërtius credits to Callimachus in his Iambics ) Bathycles of Arcadia states in his will that an expensive bowl " 'should be given to him who had done most good by his wisdom.' So it
5610-460: Is centered at Athens , it has been calculated that this construction would yield a symmetric compass rose with approximately 30° angles all around. If set out on a compass card, Aristotle's system could be conceived of as a twelve-wind rose with four cardinal winds (N, E, S, W), four "solstitial winds" (loosely speaking, NW, NE, SE, SW), two "polar winds" (roughly NNW, NNE) and two "non-winds" (SSW, SSE). Aristotle explicitly groups Aparctias (N) and
5775-437: Is considered possible that Thales visited Egypt, since Miletus had a permanent colony there (namely Naucratis ). It is also said Thales had close contacts with the priests of Thebes who instructed him, or even that he instructed them in geometry. It is also possible Thales knew about Egypt from accounts of others, without actually visiting it. Aside from Egypt, the other mathematically advanced, ancient civilization before
5940-468: Is controversial." Others historians, such as D. R. Dicks, take issue with the idea of Babylonian influence on Greek mathematics. For until around the time of Hipparchus (c. 190–120 BC) their sexagesimal system was unknown. Herodotus wrote the Greeks learnt the gnomon from the Babylonians. Thales's follower Anaximander is credited with introducing the gnomon to the Greeks. Herodotus also wrote that
6105-495: Is frequent reference to four cardinal directions . The names of the directions seem to be associated with physical landmarks for the ancient Israelites living in the region of Judea , e.g. East is referred to as kedem , which may derive from "edom" ("red"), and may be a reference to the color of the rising dawn , or the red sandstone cliffs of the Land of Edom to the east; North is referred to as saphon , from Mount Zaphon on
6270-400: Is his own thinking, his statement that Thales held it as water is generally accepted as genuinely originating with Thales. Writing centuries later, Diogenes Laërtius also states that Thales taught "Water constituted ( ὑπεστήσατο , 'stood under') the principle of all things." According to Aristotle: That from which is everything that exists and from which it first becomes and into which it
6435-575: Is implied at several places in the Old Testament. "Four winds" are referred to in the Bible in several places. Kedem (East) is used frequently as the name of a scorching wind that blows from the east. It is related to the modern word קדימה " kadima ", meaning "forward". There are several passages referring to the scattering of people "to all the winds". Unlike the Biblical Israelites,
6600-487: Is not mandatory to be hired by the media. Each science has its own unique sets of laboratory equipment. In the atmosphere, there are many things or qualities of the atmosphere that can be measured. Rain, which can be observed, or seen anywhere and anytime was one of the first atmospheric qualities measured historically. Also, two other accurately measured qualities are wind and humidity. Neither of these can be seen but can be felt. The devices to measure these three sprang up in
6765-698: Is now thought to represent speculative rationalization and reconstruction by later authors, rather than concrete accomplishments of Thales himself or his contemporaries. According to one author, while visiting Egypt, Thales observed that when the Egyptians drew two intersecting lines, they would measure the vertical angles to make sure that they were equal. Thales concluded that one could prove that all vertical angles are equal if one accepted some general notions such as: all straight angles are equal, equals added to equals are equal, and equals subtracted from equals are equal. Pamphila says that, having learnt geometry from
Classical compass winds - Misplaced Pages Continue
6930-424: Is probable that for ancient settled populations, local physical landmarks (e.g. mountains, deserts, settlements) were the initial and most immediate markers of general direction ("towards the coast", "towards the hills", "towards the lands of Xanadu", etc.). Astral phenomena, in particular the position of the sun at dawn and dusk, were also used to denote direction. The association of geographic direction with wind
7095-402: Is rendered at last, its substance remaining under it, but transforming in qualities, that they say is the element and principle of things that are. …For it is necessary that there be some nature ( φύσις ), either one or more than one, from which become the other things of the object being saved... [The first philosophers] do not all agree as to the number and the nature of these principles. Thales
7260-634: Is said to have been built by Andronicus of Cyrrhus , of uncertain dates. From the style of the sculptures the tower is usually dated around 50 BC, not long before Varro and Vitruvius mention it. An alternative possibility is that it was part of the generosity of Attalus III of Pergamon (d. 131 BC) who built the Stoa of Attalus in the city. Either way, it is after Eratosthenes. It gives as its eight winds Boreas (not Aparctias, N), Caecias (NE), Apeliotes (E), Eurus (SE), Notos (S), Lips (SW), Zephyrus (W) and Sciron (NW, variant of Argestes). Boreas' reappearance in
7425-570: Is the unity of substance. Not merely the empirical claim that all is water, but the deeper philosophical claim that all is one. For example, Friedrich Nietzsche , in his Philosophy in the Tragic Age of the Greeks , wrote: Greek philosophy seems to begin with an absurd notion, with the proposition that water is the primal origin and the womb of all things. Is it really necessary for us to take serious notice of this proposition? It is, and for three reasons. First, because it tells us something about
7590-422: Is uncertain. Among tentative propositions is that Boreas might come from "boros", an old variant of "oros" ( Greek for "mountains", which were to the north geographically). An alternative hypothesis is that it may come from "boros" meaning "voracious". Another is that it comes from the phrase ἀπὸ τῆς βοῆς ("from the roar"), a reference to its violent and loud noise. Notos probably comes from "notios" ("moist",
7755-454: The 22° and 46° halos . The ancient Greeks were the first to make theories about the weather. Many natural philosophers studied the weather. However, as meteorological instruments did not exist, the inquiry was largely qualitative, and could only be judged by more general theoretical speculations. Herodotus states that Thales predicted the solar eclipse of 585 BC. He studied Babylonian equinox tables. According to Seneca, he gave
7920-413: The Earth's magnetic field lines. In 1494, Christopher Columbus experienced a tropical cyclone, which led to the first written European account of a hurricane. In 1686, Edmund Halley presented a systematic study of the trade winds and monsoons and identified solar heating as the cause of atmospheric motions. In 1735, an ideal explanation of global circulation through study of the trade winds
8085-628: The Kitab al-Nabat (Book of Plants), in which he deals with the application of meteorology to agriculture during the Arab Agricultural Revolution . He describes the meteorological character of the sky, the planets and constellations , the sun and moon , the lunar phases indicating seasons and rain, the anwa ( heavenly bodies of rain), and atmospheric phenomena such as winds, thunder, lightning, snow, floods, valleys, rivers, lakes. In 1021, Alhazen showed that atmospheric refraction
8250-484: The Peripatetic school , in his On Weather Signs and "On Winds" (c. 300 BCE), adopted the same wind system as Aristotle, with only some slight differences, e.g. Theophrastus misspelled Thrascias as "Thracias" and seemed to distinguish between Apractias and Boreas (perhaps as " North by west " and "North" wind respectively). In the pseudo-Aristotelean fragment Ventorum Situs (often attributed to Theophrastus ), there
8415-595: The Phoenicias wind for the SSE (blows locally in some places), but suggests nothing for SSW. So, seen this way, Aristotle really has an asymmetric windrose of ten winds, as two winds are effectively missing or only local. (Variants: Olympias ( ὀλυμπίας ), Sciron ( σκίρων ) Notice that in the Aristotelean system, old Eurus is shunted from its traditional position in the cardinal East by Apeliotes ( ἀπηλιώτης ), meaning "from
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#17328416380248580-607: The Smithsonian Institution began to establish an observation network across the United States under the leadership of Joseph Henry . Similar observation networks were established in Europe at this time. The Reverend William Clement Ley was key in understanding of cirrus clouds and early understandings of Jet Streams . Charles Kenneth Mackinnon Douglas , known as 'CKM' Douglas read Ley's papers after his death and carried on
8745-541: The archonship of Damasius at Athens about 582 BC and that Thales was the first sage. The sages were associated with the Delphic maxims , a quote or maxim attributed to each one inscribed on the Temple of Apollo at Delphi . Thales has arguably the most famous of all, gnothi seauton or know thyself . According to the 10th-century Byzantine encyclopedia the Suda , the proverb
8910-417: The heat capacity of gases varies inversely with atomic weight . In 1824, Sadi Carnot analyzed the efficiency of steam engines using caloric theory; he developed the notion of a reversible process and, in postulating that no such thing exists in nature, laid the foundation for the second law of thermodynamics . In 1716, Edmund Halley suggested that aurorae are caused by "magnetic effluvia" moving along
9075-585: The meteorological properties of the winds, e.g. that the winds on the NW-SE axis are generally dry, while the NE-SW winds are wet (NE producing heavier clouds than SW). N and NNE bring snow. Winds from the whole northwestern sector (NW, NNW, N) are described as cold, strong, cloud-clearing winds that can bring lightning and hurricanes with them. Aristotle also makes special note of the periodic bending summer Etesian winds, which comes from different directions depending on where
9240-632: The phlogiston theory . In 1777, Antoine Lavoisier discovered oxygen and developed an explanation for combustion. In 1783, in Lavoisier's essay "Reflexions sur le phlogistique," he deprecates the phlogiston theory and proposes a caloric theory . In 1804, John Leslie observed that a matte black surface radiates heat more effectively than a polished surface, suggesting the importance of black-body radiation . In 1808, John Dalton defended caloric theory in A New System of Chemistry and described how it combines with matter, especially gases; he proposed that
9405-438: The seked from the height of the stick and its distance from the point of insertion to the line of sight. Thales was also a noted astronomer, acknowledged in antiquity for describing the position of Ursa Minor , and he thought the constellation might be useful as a guide for navigation at sea. He calculated the duration of the year and the timings of the equinoxes and solstices . He is additionally attributed with calculating
9570-416: The true north ( Pole Star , Septentrio). Pliny the Elder in his Natural History (C. 77 CE) after noting that twelve was an exaggeration, goes on to note that the "moderns" have reduced it to eight. He lists them as Septentrio (N), Aquilo (NNE), Subsolanus (E), Vulturnus (SE), Auster (S), Africus (SW), Favonius (W) and Corus (NW). Notice that Caecias (NE) is not part of this octet. Instead, Pliny puts
9735-500: The 5th century BC, Thales predicted a solar eclipse in 585 BC. Assuming one's acme (or floruit ) occurred at the age of 40, the chronicle of Apollodorus of Athens , written during the 2nd century BC, therefore placed Thales's birth about the year 625 BC. While the probability is that Thales was as Greek as most Milesians, Herodotus described Thales as "a Phoenician by remote descent". Diogenes Laërtius references Herodotus, Duris , and Democritus , who all agree "that Thales
9900-516: The Aristotelian method. The work of Theophrastus remained a dominant influence in weather forecasting for nearly 2,000 years. Meteorology continued to be studied and developed over the centuries, but it was not until the Renaissance in the 14th to 17th centuries that significant advancements were made in the field. Scientists such as Galileo and Descartes introduced new methods and ideas, leading to
10065-527: The Egyptians, Thales was the first to inscribe in a circle a right-angled triangle, whereupon he sacrificed an ox . This is sometimes cited as history's first mathematical discovery. Due to the variations among testimonies, such as the story of the ox sacrifice being accredited to Pythagoras upon discovery of the Pythagorean theorem rather than Thales, some historians (such as D. R. Dicks) question whether such anecdotes have any historical worth whatsoever. It
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#173284163802410230-502: The Elder , are adamant that Homer mentioned only four winds. Hesiod (c. 700 BCE) in his Theogony (c. 735) gives the four winds mythical personification as gods, the Anemoi ( Ἄνεμοι ), the children of the Titan gods Astraeus (stars) and Eos (dawn). But Hesiod himself refers to only three winds by name – Boreas , Notos and Zephyrus – which he called the "good winds" and the "children of
10395-468: The Great was the first to propose that each drop of falling rain had the form of a small sphere, and that this form meant that the rainbow was produced by light interacting with each raindrop. Roger Bacon was the first to calculate the angular size of the rainbow. He stated that a rainbow summit cannot appear higher than 42 degrees above the horizon. In the late 13th century and early 14th century, Kamāl al-Dīn al-Fārisī and Theodoric of Freiberg were
10560-416: The Greeks was Babylonia, another commonplace attribution of travel for a mathematically-minded philosopher. At least one ancient historian, Josephus , claims Thales visited Babylonia. Historians Roger L. Cooke and B.L. Van der Waerden come down on the side of Babylonian mathematics influencing the Greeks, citing the use of e. g. the sexagesimal system (or base 60). Cooke notes "This relation, however,
10725-524: The Modification of Clouds , in which he assigns cloud types Latin names. In 1806, Francis Beaufort introduced his system for classifying wind speeds . Near the end of the 19th century the first cloud atlases were published, including the International Cloud Atlas , which has remained in print ever since. The April 1960 launch of the first successful weather satellite , TIROS-1 , marked
10890-456: The North slot in place of Aparctias is notable. The winds are personified in stone reliefs as gods ( Anemoi ) at the top of the faces. Vitruvius says the tower was topped with a weather vane . The Greek wind system was adopted by the Romans, partly under their Greek nomenclature, but increasingly also under new Latin names. Roman poet Virgil , in his Georgics (c. 29 BCE) refers to several of
11055-548: The North, Boreas shunted to NNE, Euronotus instead of Phoenicias, Circius as alternate of Thrascias). The differences of De Mundo from Timosthenes are that (1) it introduces Libophoenix as another name for Libonotos (Leuconotos not mentioned); (2) two alternates to Argestes are mentioned – Iapyx (as in the Ventorum ) and Olympias (as in Aristotle) (Timosthenes mentions no variants for this wind), (3) like Aristotle, De Mundo refers to
11220-589: The SE, Euronotus (previously SSE) is promoted to the vacant SE position. Finally, a new name, Caurus , is introduced as the NW wind. This is almost certainly a misspelling of Corus (NW). Aulus Gellius gives some information about local winds. He mentions Circius as a local wind in Gaul , known for its dizzying, circular motion, and notes its alternate spelling Cercius in Hispania (probably
11385-689: The Sun" or from "the heat of the Sun". Old Boreas is mentioned only as an alternative name to Aparctias ( ἀπαρκτίας ), which means "from the Bear", that is, the Ursa Major , the Arctic Circle . Among the new winds are the Argestes ( ἀργέστης ) meaning "clearing" or "brightening", a reference to the northwest wind sweeping away clouds. Argestes's variants, Olympias ( ὀλυμπίας ) and Sciron ( σκίρων ) are local Athenian names,
11550-472: The advancement in weather forecasting and satellite technology, meteorology has become an integral part of everyday life, and is used for many purposes such as aviation, agriculture, and disaster management. In 1441, King Sejong 's son, Prince Munjong of Korea, invented the first standardized rain gauge . These were sent throughout the Joseon dynasty of Korea as an official tool to assess land taxes based upon
11715-424: The ancient Greeks had four winds ( Anemoi ). The peoples of early Greece reportedly conceived of only two winds – the winds from the north, known as Boreas ( Βορέας ), and the winds from the south, known as Notus ( Νότος ). But two more winds – Eurus ( Εὖρος ) from the east and Zephyrus ( Ζέφυρος ) from the west – were added soon enough. The etymology of the names of the four archaic Greek winds
11880-498: The appendix Les Meteores , he applied these principles to meteorology. He discussed terrestrial bodies and vapors which arise from them, proceeding to explain the formation of clouds from drops of water, and winds, clouds then dissolving into rain, hail and snow. He also discussed the effects of light on the rainbow. Descartes hypothesized that all bodies were composed of small particles of different shapes and interwovenness. All of his theories were based on this hypothesis. He explained
12045-412: The atmosphere can be divided into distinct areas that depend on both time and spatial scales. At one extreme of this scale is climatology. In the timescales of hours to days, meteorology separates into micro-, meso-, and synoptic scale meteorology. Respectively, the geospatial size of each of these three scales relates directly with the appropriate timescale. Other subclassifications are used to describe
12210-456: The atmosphere from a remote location and, usually, stores the data where the instrument is located. Radar and Lidar are not passive because both use EM radiation to illuminate a specific portion of the atmosphere. Weather satellites along with more general-purpose Earth-observing satellites circling the earth at various altitudes have become an indispensable tool for studying a wide range of phenomena from forest fires to El Niño . The study of
12375-666: The beginning of the age where weather information became available globally. In 1648, Blaise Pascal rediscovered that atmospheric pressure decreases with height, and deduced that there is a vacuum above the atmosphere. In 1738, Daniel Bernoulli published Hydrodynamics , initiating the Kinetic theory of gases and established the basic laws for the theory of gases. In 1761, Joseph Black discovered that ice absorbs heat without changing its temperature when melting. In 1772, Black's student Daniel Rutherford discovered nitrogen , which he called phlogisticated air , and together they developed
12540-460: The best known products of meteorologists for the public, weather presenters on radio and television are not necessarily professional meteorologists. They are most often reporters with little formal meteorological training, using unregulated titles such as weather specialist or weatherman . The American Meteorological Society and National Weather Association issue "Seals of Approval" to weather broadcasters who meet certain requirements but this
12705-401: The calculations led to unrealistic results. Though numerical analysis later found that this was due to numerical instability . Starting in the 1950s, numerical forecasts with computers became feasible. The first weather forecasts derived this way used barotropic (single-vertical-level) models, and could successfully predict the large-scale movement of midlatitude Rossby waves , that is,
12870-442: The cardinal winds, e.g. as western winds bring rain, then when Homer says a "stormy Boreas" he means a different wind from a "loud Boreas" (i.e. wet north = NW, loud north = N) Nonetheless, while it seems that Homer may have realized that there were more than four winds, he did not use those epithets systematically enough to permit us to conclude that he also embraced a six- or eight-point windrose. Other classical writers, e.g. Pliny
13035-492: The chaotic nature of the atmosphere. Mathematical models used to predict the long term weather of the Earth ( climate models ), have been developed that have a resolution today that are as coarse as the older weather prediction models. These climate models are used to investigate long-term climate shifts, such as what effects might be caused by human emission of greenhouse gases . Meteorologists are scientists who study and work in
13200-413: The church and princes. This was supported by scientists like Johannes Muller , Leonard Digges , and Johannes Kepler . However, there were skeptics. In the 14th century, Nicole Oresme believed that weather forecasting was possible, but that the rules for it were unknown at the time. Astrological influence in meteorology persisted until the eighteenth century. Gerolamo Cardano 's De Subilitate (1550)
13365-613: The climate with public health. During the Age of Enlightenment meteorology tried to rationalise traditional weather lore, including astrological meteorology. But there were also attempts to establish a theoretical understanding of weather phenomena. Edmond Halley and George Hadley tried to explain trade winds . They reasoned that the rising mass of heated equator air is replaced by an inflow of cooler air from high latitudes. A flow of warm air at high altitude from equator to poles in turn established an early picture of circulation. Frustration with
13530-422: The clouds and winds extended up to 111 miles, but Posidonius thought that they reached up to five miles, after which the air is clear, liquid and luminous. He closely followed Aristotle's theories. By the end of the second century BC, the center of science shifted from Athens to Alexandria , home to the ancient Library of Alexandria . In the 2nd century AD, Ptolemy 's Almagest dealt with meteorology, because it
13695-672: The contemporary 12-wind compass schema. In his Attic Nights (written c. 159), the Athens -raised Latin writer Aulus Gellius , possibly inspired by the Tower of the Winds in that city, reduces the Latin rose to from twelve to eight winds, the principal winds, for which he gives both the Latin and Greek terms. He lists them as: Among the novelties is the disappearance of Caecias (NE, like in Pliny), although he does make
13860-752: The control of the gods. The ability to predict rains and floods based on annual cycles was evidently used by humans at least from the time of agricultural settlement if not earlier. Early approaches to predicting weather were based on astrology and were practiced by priests. The Egyptians had rain-making rituals as early as 3500 BC. Ancient Indian Upanishads contain mentions of clouds and seasons . The Samaveda mentions sacrifices to be performed when certain phenomena were noticed. Varāhamihira 's classical work Brihatsamhita , written about 500 AD, provides evidence of weather observation. Cuneiform inscriptions on Babylonian tablets included associations between thunder and rain. The Chaldeans differentiated
14025-491: The description of what is now known as the hydrologic cycle . His work would remain an authority on meteorology for nearly 2,000 years. The book De Mundo (composed before 250 BC or between 350 and 200 BC) noted: After Aristotle, progress in meteorology stalled for a long time. Theophrastus compiled a book on weather forecasting, called the Book of Signs , as well as On Winds . He gave hundreds of signs for weather phenomena for
14190-405: The discovery that a circle is bisected by its diameter, that the base angles of an isosceles triangle are equal and that vertical angles are equal. Two fundamental theorems of elementary geometry are customarily called Thales's theorem : one of them has to do with a triangle inscribed in a circle and having the circle's diameter as one side; the other, also called the intercept theorem ,
14355-446: The early Greeks maintained two separate and distinct systems of cardinal directions and winds, at least for a while. Astral phenomena were used to define four cardinal points : arctos ( ἄρκτος , "bear", the Ursa Major , for North), anatole ( ἀνατολή , "sunrise" or eos "dawn", East), mesembria ( μεσημβρία , "noon", South) and dysis ( δύσις , "sunset" or hesperus , "evening", West). Heraclitus , in particular, suggests that
14520-626: The early study of weather systems. Nineteenth century researchers in meteorology were drawn from military or medical backgrounds, rather than trained as dedicated scientists. In 1854, the United Kingdom government appointed Robert FitzRoy to the new office of Meteorological Statist to the Board of Trade with the task of gathering weather observations at sea. FitzRoy's office became the United Kingdom Meteorological Office in 1854,
14685-410: The earth, and felt there were really only eight equally sized sectors, and that other winds were but local variations of these eight principal winds . If true, that would make Eratosthenes the inventor of the eight-wind compass rose . Eratosthenes was a disciple of Timosthenes and is said to have drawn principally from his work. But they part ways on this. Both recognized that Aristotle's ten-wind rose
14850-482: The existence of a circulation cell in the mid-latitudes, and the air within deflected by the Coriolis force resulting in the prevailing westerly winds. Late in the 19th century, the motion of air masses along isobars was understood to be the result of the large-scale interaction of the pressure gradient force and the deflecting force. By 1912, this deflecting force was named the Coriolis effect. Just after World War I,
15015-467: The explanation that the cause of the Nile 's annual floods was due to northerly winds hindering its descent by the sea. Anaximander and Anaximenes thought that thunder and lightning was caused by air smashing against the cloud, thus kindling the flame. Early meteorological theories generally considered that there was a fire-like substance in the atmosphere. Anaximander defined wind as a flowing of air, but this
15180-542: The fact that the "east" (sunrise) and "west" (sunset) are not stable on the horizon, but depend on the season, i.e. during the winter, the sun rises and sets a little further south than in the summer, Consequently, the Homeric system may have had six winds – Boreas (N) and Notos (S) on the meridian axis, and the other four on diagonals: Zephyrus (NW), Eurus (NE), Apeliotes (SE) and Argestes (SW). Strabo, quoting Posidonius notes that Homer sometimes used epithets of qualitative attributes to append ordinal directions to
15345-492: The field after weather observation networks were formed across broad regions. Prior attempts at prediction of weather depended on historical data. It was not until after the elucidation of the laws of physics, and more particularly in the latter half of the 20th century, the development of the computer (allowing for the automated solution of a great many modelling equations) that significant breakthroughs in weather forecasting were achieved. An important branch of weather forecasting
15510-443: The field of meteorology. The American Meteorological Society publishes and continually updates an authoritative electronic Meteorology Glossary . Meteorologists work in government agencies , private consulting and research services, industrial enterprises, utilities, radio and television stations , and in education . In the United States, meteorologists held about 10,000 jobs in 2018. Although weather forecasts and warnings are
15675-652: The first weather observing network, that consisted of meteorological stations in Florence , Cutigliano , Vallombrosa , Bologna , Parma , Milan , Innsbruck , Osnabrück , Paris and Warsaw . The collected data were sent to Florence at regular time intervals. In the 1660s Robert Hooke of the Royal Society of London sponsored networks of weather observers. Hippocrates ' treatise Airs, Waters, and Places had linked weather to disease. Thus early meteorologists attempted to correlate weather patterns with epidemic outbreaks, and
15840-561: The first Greek to go beyond treating these "winds" merely as meteorological phenomena and to begin viewing them properly as points of geographic direction. Timosthenes (through Agathemerus) assigns each of the 12 winds to geographical locations and peoples (relative to Rhodes ): Modern scholars to conjecture that Timosthenes, in his lost periplus , might have made ample use of these winds for sailing directions (which may help explain Agathemerus's eagerness to credit Timosthenes for "inventing"
16005-447: The first among them. Also, while the other Seven Sages were strictly law-givers and statesmen and not speculative philosophers, Plutarch noted "it would seem that Thales was the only wise man of the time who carried his speculations beyond the realm of the practical." Thales's most famous idea was his philosophical and cosmological thesis that all is water, which comes down to us through a passage from Aristotle 's Metaphysics . In
16170-593: The first person in the western world to apply deductive reasoning to geometry, making him the West's "first mathematician." He is also credited with the West's oldest definition of number : a "collection of units", "following the Egyptian view". The evidence for the primacy of Thales comes to us from a book by Proclus , who lived a thousand years afterward but is believed to have had a copy of Eudemus 's lost book History of Geometry (4th century BC). Proclus wrote that Thales
16335-491: The first philosopher in the Greek tradition , breaking from the prior use of mythology to explain the world and instead using natural philosophy . He is thus otherwise referred to as the first to have engaged in mathematics , science , and deductive reasoning . The first philosophers followed him in explaining all of nature as based on the existence of a single ultimate substance . Thales theorized that this single substance
16500-400: The first time, a practical method for quickly gathering surface weather observations from a wide area. This data could be used to produce maps of the state of the atmosphere for a region near the Earth's surface and to study how these states evolved through time. To make frequent weather forecasts based on these data required a reliable network of observations, but it was not until 1849 that
16665-407: The first to give the correct explanations for the primary rainbow phenomenon. Theoderic went further and also explained the secondary rainbow. By the middle of the sixteenth century, meteorology had developed along two lines: theoretical science based on Meteorologica , and astrological weather forecasting. The pseudoscientific prediction by natural signs became popular and enjoyed protection of
16830-633: The first weather forecasts and temperature predictions. In the 20th and 21st centuries, with the advent of computer models and big data, meteorology has become increasingly dependent on numerical methods and computer simulations. This has greatly improved weather forecasting and climate predictions. Additionally, meteorology has expanded to include other areas such as air quality, atmospheric chemistry, and climatology. The advancement in observational, theoretical and computational technologies has enabled ever more accurate weather predictions and understanding of weather pattern and air pollution. In current time, with
16995-582: The forerunner of the Japan Meteorological Agency , began constructing surface weather maps in 1883. The United States Weather Bureau (1890) was established under the United States Department of Agriculture . The Australian Bureau of Meteorology (1906) was established by a Meteorology Act to unify existing state meteorological services. In 1904, Norwegian scientist Vilhelm Bjerknes first argued in his paper Weather Forecasting as
17160-516: The form of wind. He explained thunder by saying that it was due to ice colliding in clouds, and in Summer it melted. In the thirteenth century, Aristotelian theories reestablished dominance in meteorology. For the next four centuries, meteorological work by and large was mostly commentary . It has been estimated over 156 commentaries on the Meteorologica were written before 1650. Experimental evidence
17325-406: The founder of this type of philosophy says that it is water. Aristotle further adds: Presumably he derived this assumption from seeing that the nutriment of everything is moist, and that heat itself is generated from moisture and depends upon it for its existence (and that from which a thing is generated is always its first principle). He derived his assumption from this; and also from the fact that
17490-478: The half-wind Aquilo (NNE) there instead. It seems Pliny is aware Aquilo is a half-wind, because since he says it lies "in between Septentrio and the summer sunrise" (although in a later chapter he places it at the summer sunrise). If the first version is taken, this means Pliny's eight-wind compass is asymmetric. Pliny goes on to mention that Aquilo is also "named Aparctias and Boreas" (the Boreas identification with NNE
17655-522: The half-winds Thrascias (NNW) and Meses (NNE) together as "north winds" and Argestes (NW) and Zephyrus (W) together as "west winds" — but he goes on to note that both the north and west winds could be classified as "generally northerly" ( Boreae ), since they all tend to be cold. Similarly Lips (SW) and Notos (S) are "south winds" and Eurus (SE) and Apeliotes (E) are "east winds", but once again, both south and east winds are "generally southerly" ( Notiae ) because are all relatively warm (Aristotle reasons that as
17820-402: The height of the pyramids by their shadows at the moment when his own shadow was equal to his height. According to Plutarch, it pleased the pharoah Amasis . More practically, Thales was said to have the ability to measure the distances of ships at sea. These stories indicate familiarity with the intercept theorem, and for this reason the 26th proposition in the first book of Euclid's Elements
17985-512: The idea of having to worry about children. Nevertheless, several years later, anxious for family, he adopted his nephew Cybisthus. The culture of Archaic Greece was heavily influenced by those of the Levant and Mesopotamia . It is said Thales was engaged in trade and visited either Egypt or Babylonia . However, there is no strong evidence that Thales ever visited countries in the Near East , and
18150-402: The issue is disputed among scholars. Visits to such places were a commonplace attribution to various philosophers by later writers, especially when these writers tried to explain the origin of their mathematical knowledge, such as with Thales or Pythagoras or Eudoxus . Several ancient authors assume that Thales, at one point in his life, visited Egypt , where he learned about geometry. It
18315-413: The lack of discipline among weather observers, and the poor quality of the instruments, led the early modern nation states to organise large observation networks. Thus, by the end of the 18th century, meteorologists had access to large quantities of reliable weather data. In 1832, an electromagnetic telegraph was created by Baron Schilling . The arrival of the electrical telegraph in 1837 afforded, for
18480-500: The lakes and the Nile. Hippocrates inquired into the effect of weather on health. Eudoxus claimed that bad weather followed four-year periods, according to Pliny. These early observations would form the basis for Aristotle 's Meteorology , written in 350 BC. Aristotle is considered the founder of meteorology. One of the most impressive achievements described in the Meteorology is
18645-437: The late 16th century and first half of the 17th century a range of meteorological instruments were invented – the thermometer , barometer , hydrometer , as well as wind and rain gauges. In the 1650s natural philosophers started using these instruments to systematically record weather observations. Scientific academies established weather diaries and organised observational networks. In 1654, Ferdinando II de Medici established
18810-520: The local Phoenicias (SSE). His highlighting of the Italian "Circius" as a major variant of Thrascias (NNW) could be the first indication of the notorious Mistral wind of the west Mediterranean. Another major change in Timoesthenes is that he shunts Boreas out of the North position and into NNE (replacing Meses) – which will become customary in later authors. Timosthenes is also significant for being perhaps
18975-443: The mechanical, self-emptying, tipping bucket rain gauge. In 1714, Gabriel Fahrenheit created a reliable scale for measuring temperature with a mercury-type thermometer . In 1742, Anders Celsius , a Swedish astronomer, proposed the "centigrade" temperature scale, the predecessor of the current Celsius scale. In 1783, the first hair hygrometer was demonstrated by Horace-Bénédict de Saussure . In 1802–1803, Luke Howard wrote On
19140-448: The mid-15th century and were respectively the rain gauge , the anemometer, and the hygrometer. Many attempts had been made prior to the 15th century to construct adequate equipment to measure the many atmospheric variables. Many were faulty in some way or were simply not reliable. Even Aristotle noted this in some of his work as the difficulty to measure the air. Sets of surface measurements are important data to meteorologists. They give
19305-517: The morning" (engendering a little confusion, as it might be read as they were all easterly winds – although curious that Eurus is not among them). Hesiod refers to other "bad winds", but not by name. The Greek physician Hippocrates (c. 400 BC), in his On Airs, Water and Places , refers to four winds, but designates them not by their Homeric names, but rather from the cardinal direction from which they blow (arctos, anatole, dusis, etc.) He does, however, recognize six geographic points – north, south and
19470-450: The names of the classical winds, both in Greek and in Latin. The Vatican table lists them as follows: Meteorology Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting . The study of meteorology dates back millennia , though significant progress in meteorology did not begin until the 18th century. The 19th century saw modest progress in
19635-559: The navigator Timosthenes of Rhodes (c. 282 BCE) had developed a system of 12 winds by adding four winds to the eight. (Agathemerus is, of course, incorrect – Aristotle had at least ten winds, not eight). Timosthenes's list (according to Agathemerus) was Aparctias (N), Boreas (not Meses, NNE), Caecias (NE), Apeliotes (E), Eurus (SE), "Phoenicias is also called Euronotos" (SSE), Notos (S), "Leuconotos alias Libonotos" (first mention, SSW), Lips (SW), Zephyrus (W), Argestes (NW) and "Thrascias alias Circius" (NNW). In many ways, Timosthenes marks
19800-549: The night, with change being likely at one of these divisions. Applying the divisions and a principle of balance in the yearly weather, he came up with forecasts like that if a lot of rain falls in the winter, the spring is usually dry. Rules based on actions of animals are also present in his work, like that if a dog rolls on the ground, it is a sign of a storm. Shooting stars and the Moon were also considered significant. However, he made no attempt to explain these phenomena, referring only to
19965-517: The northern edge of Syria, South is often negev , from the Negev desert to the south, and West is yam ("sea", meaning the Mediterranean Sea ). Orientation seems to be to the East, in the direction of the rising sun, with the result that the terms kedem , saphon and negev became generalized with "facing", "left" and "right" side of anything. The association of cardinal directions with winds
20130-441: The observer lives. Aristotle had aggrandized the wind system beyond Homer to ten winds, but he left it unbalanced. It would be left to subsequent geographers to either add two more winds (to SSW and SSE) to make it into a symmetric 12-wind compass (as Timosthenes would do), or subtract two winds (NNW and NNE) to make it into a symmetric 8-wind compass (as Eratosthenes would do). Theophrastus of Eresos, Aristotle's successor in
20295-474: The observer's position. This was likely furthered by sailors who, far from landmarks at sea, nonetheless recognized a particular wind by its qualities and referred to it by a familiar name. The final step, completing the circle, was to use the proper names of the winds to denote general cardinal directions of the compass rose . This would take a little longer to work itself through. In the Hebrew Bible , there
20460-507: The opposite effect. Rene Descartes 's Discourse on the Method (1637) typifies the beginning of the scientific revolution in meteorology. His scientific method had four principles: to never accept anything unless one clearly knew it to be true; to divide every difficult problem into small problems to tackle; to proceed from the simple to the complex, always seeking relationships; to be as complete and thorough as possible with no prejudice. In
20625-516: The pattern of atmospheric lows and highs . In 1959, the UK Meteorological Office received its first computer, a Ferranti Mercury . In the 1960s, the chaotic nature of the atmosphere was first observed and mathematically described by Edward Lorenz , founding the field of chaos theory . These advances have led to the current use of ensemble forecasting in most major forecasting centers, to take into account uncertainty arising from
20790-652: The position of the Pleiades . Plutarch indicates that in his day (c. AD 100) there was an extant work, the Astronomy , composed in verse and attributed to Thales. While some say he left no writings, others say that he wrote On the Solstice and On the Equinox . The Nautical Star-guide has also been attributed to him, but this was disputed even in ancient times. No writing attributed to him has survived. Lobon of Argus asserted that
20955-526: The position of the constellation Ursa Major is also attributed to Thales, as well as the timings of the solstices and equinoxes . He was also an engineer , known for having diverted the Halys River . The main source concerning the details of Thales's life and career is the doxographer Diogenes Laërtius , in his third-century-AD work Lives and Opinions of the Eminent Philosophers . While it
21120-398: The practice of dividing the day into 12 parts, and the polos , came to the Greeks from the Babylonians. Yet this too is disputed, for example by historian L. Zhmud, who points out the gnomon was known to both Egyptians and Babylonians, the division of the day into twelve parts (and by analogy the year) was known to the Egyptians already in the 2nd millennium BC , and the idea of the polos
21285-480: The primal origin of all things; second, because it does so in language devoid of image or fable, and finally, because contained in it, if only embryonically, is the thought, "all things are one." Megiston topos: apanta gar chorei ( Μέγιστον τόπος· ἄπαντα γὰρ χωρεῖ. ) The greatest is space, for it holds all things. —attributed to Thales Thales was known for introducing the theoretical and practical use of geometry to Greece, and has been described as
21450-415: The prognostic fluid dynamics equations that govern atmospheric flow could be neglected, and a numerical calculation scheme that could be devised to allow predictions. Richardson envisioned a large auditorium of thousands of people performing the calculations. However, the sheer number of calculations required was too large to complete without electronic computers, and the size of the grid and time steps used in
21615-521: The rain as caused by clouds becoming too large for the air to hold, and that clouds became snow if the air was not warm enough to melt them, or hail if they met colder wind. Like his predecessors, Descartes's method was deductive, as meteorological instruments were not developed and extensively used yet. He introduced the Cartesian coordinate system to meteorology and stressed the importance of mathematics in natural science. His work established meteorology as
21780-442: The scientific revolution in meteorology. Speculation on the cause of the flooding of the Nile ended when Eratosthenes , according to Proclus , stated that it was known that man had gone to the sources of the Nile and observed the rains, although interest in its implications continued. During the era of Roman Greece and Europe, scientific interest in meteorology waned. In the 1st century BC, most natural philosophers claimed that
21945-440: The seasons. He believed that fire and water opposed each other in the atmosphere, and when fire gained the upper hand, the result was summer, and when water did, it was winter. Democritus also wrote about the flooding of the Nile. He said that during the summer solstice, snow in northern parts of the world melted. This would cause vapors to form clouds, which would cause storms when driven to the Nile by northerly winds, thus filling
22110-578: The second oldest national meteorological service in the world (the Central Institution for Meteorology and Geodynamics (ZAMG) in Austria was founded in 1851 and is the oldest weather service in the world). The first daily weather forecasts made by FitzRoy's Office were published in The Times newspaper in 1860. The following year a system was introduced of hoisting storm warning cones at principal ports when
22275-439: The seeds of everything have a moist nature, whereas water is the first principle of the nature of moist things." The 1870 book Dictionary of Greek and Roman Biography and Mythology noted: In his dogma that water is the origin of things, that is, that it is that out of which every thing arises, and into which every thing resolves itself, Thales may have followed Orphic cosmogonies, while, unlike them, he sought to establish
22440-410: The southeast of Greece) and Thrascias ( θρασκίας ) from Thrace (in Aristotle's day, Thrace covered a larger area than today, including the north-northwest of Greece). Finally, Meses ( μέσης ) might simply mean "middle", presumably because it was a half-wind. The implication of reading Thrascias and Meses as half-winds, and the others as principal winds, is that this implies Aristotle's construction
22605-414: The stars were balls of dirt on fire. He seemed to correctly gather that the moon reflects the Sun's light. A crater on the Moon is named in his honor. Rather than assuming that earthquakes were the result of supernatural whims, Thales explained them by theorizing that the Earth floats on water and that earthquakes occur when the Earth is rocked by waves. He is attributed with the first observation of
22770-587: The summer and winter risings and settings – using the latter to set the boundaries for the four general winds. The ancient Greek philosopher Aristotle , in his Meteorology (c. 340 BCE), introduced a ten-to-twelve wind system. One reading of his system is that there are eight principal winds : Aparctias (N), Caecias (NE), Apeliotes (E), Eurus (SE), Notos (S), Lips (SW), Zephyrus (W) and Argestes (NW). Aristotle then goes on to add two half-winds , Thrascias (NNW) and Meses (NNE), noting that they "have no contraries". Later, however, Aristotle suggests
22935-448: The sun rises in the east, then it heats east winds longer than west winds). With this general classification, Aristotle manages to account for the archaic Greek two-wind system. The exception to this system is Caecias (NE), which Aristotle notes is "half north and half east", and thus neither generally northern nor generally southern. The local Phoenicias (SSE), is also designated as "half south and half east". Aristotle goes on to discuss
23100-427: The telegraph and photography led to the creation of weather observing networks and the ability to track storms. Additionally, scientists began to use mathematical models to make predictions about the weather. The 20th century saw the development of radar and satellite technology, which greatly improved the ability to observe and track weather systems. In addition, meteorologists and atmospheric scientists started to create
23265-514: The truth of the assertion. Hence, Aristotle, immediately after he has called him the originator of philosophy brings forward the reasons which Thales was believed to have adduced in confirmation of that assertion; for that no written development of it, or indeed any book by Thales, was extant, is proved by the expressions which Aristotle uses when he brings forward the doctrines and proofs of the Milesian. (p. 1016) Most agree that Thales's stamp on thought
23430-424: The twelve winds are: (for the derivation of the Latin etymologies, see the section on Isidore of Seville below). Oddly, Seneca says the meridian line arises from Euronotus (SSE), not Auster (S), and that the "highest" point in the north is Aquilo (NNE), not Septentrio (N). This might imply an awareness of magnetic declination , the difference between the magnetic north ( compass north, in this case Aquilo) and
23595-429: The twelve winds). (Timosthenes's geographic list above is reproduced almost verbatim centuries later, in the 8th-century work of John of Damascus and a Prague manuscript from the early 1300s.) The pseudo-Aristotelean work De Mundo (normally attributed to an anonymous copier of Posidonius , probably written between 50 BCE and 140 CE), the winds are named practically identically to Timosthenes (e.g. Aparctias alone in
23760-528: The unique, local, or broad effects within those subclasses. Thales Thales of Miletus ( / ˈ θ eɪ l iː z / THAY -leez ; Ancient Greek : Θαλῆς ; c. 626/623 – c. 548/545 BC ) was an Ancient Greek pre-Socratic philosopher from Miletus in Ionia , Asia Minor . Thales was one of the Seven Sages , founding figures of Ancient Greece . Many regard him as
23925-572: The value of his work is in preserving earlier speculation, much like Seneca's work. From 400 to 1100, scientific learning in Europe was preserved by the clergy. Isidore of Seville devoted a considerable attention to meteorology in Etymologiae , De ordine creaturum and De natura rerum . Bede the Venerable was the first Englishman to write about the weather in De Natura Rerum in 703. The work
24090-479: The variations and interactions of these variables, and how they change over time. Different spatial scales are used to describe and predict weather on local, regional, and global levels. Meteorology, climatology , atmospheric physics , and atmospheric chemistry are sub-disciplines of the atmospheric sciences . Meteorology and hydrology compose the interdisciplinary field of hydrometeorology . The interactions between Earth's atmosphere and its oceans are part of
24255-445: The will of anthropomorphic gods and heroes . Instead, Thales aimed to explain natural phenomena via rational hypotheses that referenced natural processes themselves— Logos rather than mythos . Many, most notably Aristotle, regard him as the first philosopher in the Greek tradition . Rather than theologoi or mythologoi , Aristotle referred to the first philosophers as physiologoi , or natural philosophers, and Thales as
24420-413: The winds by their old Greek names (e.g. Zephyrus, Eurus, Boreas), and introduces a few new Latin names – notably, "black Auster", "cold Aquilo" and "frigid Caurus". The Roman writer Seneca , in his Naturales quaestiones (c. 65 CE), mentions the Greek names of some of the major winds, and goes on to note that Roman scholar Varro had said there were twelve winds. As given by Seneca, the Latin names of
24585-433: The work, Aristotle reported Thales's theory that the arche or originating principle of nature was a single material substance : water. Aristotle then proceeded to proffer a number of conjectures based on his own observations to lend some credence to why Thales may have advanced this idea (though Aristotle did not hold it himself). While Aristotle's conjecture on why Thales held water as the originating principle of matter
24750-477: The writings of Thales amounted to two hundred lines. Thales thought the Earth must be a flat disk or mound of land and dirt which is floating in an expanse of water. Heraclitus Homericus states that Thales drew his conclusion from seeing moist substance turn into air, slime and earth. It seems likely that Thales viewed the land as coming from the water on which it floated and the oceans that surround it, perhaps inspired by observing silt deposits. He thought
24915-404: The year. Using his alphabetical notation, Aristotle notes that during the summer solstice the sun rises at Z (Caecias) and sets at E (Argestes); during the equinox , it rises at B (Apeliotes) and sets at A (Zephyrus), and finally during the winter solstice it rises at Δ (Eurus) and sets at Γ (Lips). So drawn on a compass rose, Aristotle's explanation yields four parallels: Assuming the viewer
25080-409: Was water . Thales thought the Earth floated on water. In mathematics, Thales is the namesake of Thales's theorem , and the intercept theorem can also be known as Thales's theorem. Thales was said to have calculated the heights of the pyramids and the distance of ships from the shore. In science, Thales was an astronomer who reportedly predicted the weather and a solar eclipse . The discovery of
25245-417: Was a summary of then extant classical sources. However, Aristotle's works were largely lost until the twelfth century, including Meteorologica . Isidore and Bede were scientifically minded, but they adhered to the letter of Scripture . Islamic civilization translated many ancient works into Arabic which were transmitted and translated in western Europe to Latin. In the 9th century, Al-Dinawari wrote
25410-407: Was another source. It was probably farming populations, attentive to rain and temperature for their crops, that noticed the qualitative differences in winds – some were humid, others dry, some hot, others cold – and that these qualities depended on where the wind was blowing from. Local directional names were used to refer to the winds, eventually giving the wind itself a proper name , irrespective of
25575-419: Was attributed to Thales. They also indicate that he was familiar with the Egyptian seked , or seqed , the ratio of the run to the rise of a slope ( cotangent ). According to Kirk & Raven, all you need for this feat is three straight sticks pinned at one end and knowledge of your altitude. One stick goes vertically into the ground. A second is made level. With the third you sight the ship and calculate
25740-468: Was considered a subset of astronomy. He gave several astrological weather predictions. He constructed a map of the world divided into climatic zones by their illumination, in which the length of the Summer solstice increased by half an hour per zone between the equator and the Arctic. Ptolemy wrote on the atmospheric refraction of light in the context of astronomical observations. In 25 AD, Pomponius Mela ,
25905-456: Was given to Thales, went the round of all the sages, and came back to Thales again. And he sent it to Apollo at Didyma , with this dedication...'Thales the Milesian, son of Examyas [dedicates this] to Delphinian Apollo after twice winning the prize from all the Greeks. ' " According to Diogenes Laërtius, Thales gained fame as a counselor when he advised the Milesians not to engage in a symmachia,
26070-428: Was less important than appeal to the classics and authority in medieval thought. In the thirteenth century, Roger Bacon advocated experimentation and the mathematical approach. In his Opus majus , he followed Aristotle's theory on the atmosphere being composed of water, air, and fire, supplemented by optics and geometric proofs. He noted that Ptolemy's climatic zones had to be adjusted for topography . St. Albert
26235-406: Was not generally accepted for centuries. A theory to explain summer hail was first proposed by Anaxagoras . He observed that air temperature decreased with increasing height and that clouds contain moisture. He also noted that heat caused objects to rise, and therefore the heat on a summer day would drive clouds to an altitude where the moisture would freeze. Empedocles theorized on the change of
26400-454: Was not used outside of Greece at this time. Thales is recognized as one of the Seven Sages of Greece, semi-legendary wise statesmen and founding figures of Ancient Greece. While which seven one chooses may change, the seven has a canonical four which includes Thales, Solon of Athens, Pittacus of Mytilene , and Bias of Priene . Diogenes Laërtius tells us that the Seven Sages were created in
26565-430: Was the first to visit Egypt and bring the Egyptian study of mathematics to Greece, and that Thales "himself discovered many propositions and disclosed the underlying principles of many others to his successors, in some case his method being more general, in others more empirical." In addition to Proclus, Hieronymus of Rhodes (3rd century BC) also cites Thales as the first Greek mathematician. Proclus attributes to Thales
26730-399: Was the first work to challenge fundamental aspects of Aristotelian theory. Cardano maintained that there were only three basic elements- earth, air, and water. He discounted fire because it needed material to spread and produced nothing. Cardano thought there were two kinds of air: free air and enclosed air. The former destroyed inanimate things and preserved animate things, while the latter had
26895-513: Was the son of Examyas and Cleobulina, and belonged to the Thelidae who are Phoenicians and amongst the noblest descendants of Cadmus and Agenor " who had been banished from Phoenicia and that Thales was enrolled as a citizen in Miletus along with Neleus . However, Friedrich Nietzsche and others interpret this quote as meaning only that his ancestors were seafaring Cadmeians from Boeotia . It
27060-407: Was unbalanced, but while Timosthenes restored balance by adding two winds to make it a symmetric twelve, Eratosthenes deducted two winds to make it a symmetric eight. It seems that, in practical appeal, Eratosthenes's reduction may have won the day. The famous octagonal " Tower of the Winds " in Athens exhibits only eight winds rather than the ten of Aristotle or the twelve of Timosthenes. The tower
27225-531: Was written by George Hadley . In 1743, when Benjamin Franklin was prevented from seeing a lunar eclipse by a hurricane , he decided that cyclones move in a contrary manner to the winds at their periphery. Understanding the kinematics of how exactly the rotation of the Earth affects airflow was partial at first. Gaspard-Gustave Coriolis published a paper in 1835 on the energy yield of machines with rotating parts, such as waterwheels. In 1856, William Ferrel proposed
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