Middle Ages

Ancient Chinese scientists and engineers made significant scientific innovations, findings and technological advances across various scientific disciplines including the natural sciences, engineering, medicine, military technology, mathematics, geology and astronomy.

Among the earliest inventions were the abacus, the sundial, and the Kongming lantern. The Four Great Inventions – the compass, gunpowder, papermaking, and printing – were among the most important technological advances, only known to Europe by the end of the Middle Ages 1000 years later. The Tang dynasty (AD 618–906) in particular was a time of great innovation. A good deal of exchange occurred between Western and Chinese discoveries up to the Qing dynasty.

Claudius Ptolemy (/ˈtɒləmi/; Ancient Greek: Πτολεμαῖος, Ptolemaios; Latin: Claudius Ptolemaeus; c. 100 – 160s/170s AD), better known mononymously as Ptolemy, was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which were important to later Byzantine, Islamic, and Western European science. The first was his astronomical treatise now known as the Almagest, originally entitled Mathēmatikḗ Syntaxis (Μαθηματικὴ Σύνταξις, Mathēmatikḗ Syntaxis, lit. 'Mathematical Treatise'). The second is the Geography, which is a thorough discussion on maps and the geographic knowledge of the Greco-Roman world. The third is the astrological treatise in which he attempted to adapt horoscopic astrology to the Aristotelian natural philosophy of his day. This is sometimes known as the Apotelesmatika (Αποτελεσματικά, 'On the Effects') but more commonly known as the Tetrábiblos (from the Koine Greek meaning 'four books'; Latin: Quadripartitum).

The Catholic Church promoted his work, which included the only mathematically sound geocentric model of the Solar System, and unlike most Greek mathematicians, Ptolemy's writings (foremost the Almagest) never ceased to be copied or commented upon, both in late antiquity and in the Middle Ages. However, it is likely that only a few truly mastered the mathematics necessary to understand his works, as evidenced particularly by the many abridged and watered-down introductions to Ptolemy's astronomy that were popular among the Arabs and Byzantines. His work on epicycles is now seen as a very complex theoretical model built in order to explain a false tenet based on faith.

European science in the Middle Ages comprised the study of nature, mathematics and natural philosophy in medieval Europe. Following the fall of the Western Roman Empire and the decline in knowledge of Greek, Christian Western Europe was cut off from an important source of ancient learning. Although a range of Christian clerics and scholars from Isidore and Bede to Jean Buridan and Nicole Oresme maintained the spirit of rational inquiry, Western Europe would see a period of scientific decline during the Early Middle Ages. However, by the time of the High Middle Ages, the region had rallied and was on its way to once more taking the lead in scientific discovery. Scholarship and scientific discoveries of the Late Middle Ages laid the groundwork for the Scientific Revolution of the Early Modern Period.

According to Pierre Duhem, who founded the academic study of medieval science as a critique of the Enlightenment theory of a 17th-century anti-Aristotelian and anticlerical scientific revolution, the various conceptual origins of that alleged revolution lay in the 12th to 14th centuries, in the works of churchmen such as Thomas Aquinas and Buridan.

Apollonius of Perga (Ancient Greek: Ἀπολλώνιος ὁ Περγαῖος Apollṓnios ho Pergaîos; c. 240 BC – c. 190 BC) was an ancient Greek geometer and astronomer known for his work on conic sections. Beginning from the earlier contributions of Euclid and Archimedes on the topic, he brought them to the state prior to the invention of analytic geometry. His definitions of the terms ellipse, parabola, and hyperbola are the ones in use today. With his predecessors Euclid and Archimedes, Apollonius is generally considered among the greatest mathematicians of antiquity.

Aside from geometry, Apollonius worked on numerous other topics, including astronomy. Most of this work has not survived, where exceptions are typically fragments referenced by other authors like Pappus of Alexandria. His hypothesis of eccentric orbits to explain the apparently aberrant motion of the planets, commonly believed until the Middle Ages, was superseded during the Renaissance. The Apollonius crater on the Moon is named in his honor.

Ukraine is a country in Eastern Europe. It is the second-largest country in Europe after Russia, which borders it to the east and northeast. Ukraine also borders Belarus to the north; Poland and Slovakia to the west; Hungary, Romania and Moldova to the southwest; and the Black Sea and the Sea of Azov to the south and southeast. Kyiv is the nation's capital and largest city, followed by Kharkiv, Odesa, and Dnipro. Ukraine's official language is Ukrainian.

Humans have inhabited Ukraine since 32,000 BC. During the Middle Ages, it was the site of early Slavic expansion and later became a key centre of East Slavic culture under the state of Kievan Rus', which emerged in the 9th century. Kievan Rus' became the largest and most powerful realm in Europe in the 10th and 11th centuries, but gradually disintegrated into rival regional powers before being destroyed by the Mongols in the 13th century. For the next 600 years the area was contested, divided, and ruled by a variety of external powers, including the Grand Duchy of Lithuania, the Kingdom of Poland, the Polish–Lithuanian Commonwealth, the Austrian Empire, the Ottoman Empire, and the Tsardom of Russia.

Cape Emine (Bulgarian: Нос Емине [ˈnɔs ˈɛminɛ]) is a headland located at the Bulgarian Black Sea Coast. It is located 79 kilometres (49 mi) south of Varna, 55 km (34 mi) north of Burgas and 14 km (9 mi) south of Obzor. It forms the tip of Stara Planina. Cape Emine is said to be Bulgaria's stormiest cape.

In the Middle Ages, there was a fortress called Emona on Cape Emine. Its name was derived from Aemon, the ancient name for Stara Planina. Nowadays, only some ruins of the fortress are left. There are also remnants of a monastery and a lighthouse. The village of Emona is located nearby.

A world map is a map of most or all of the surface of Earth. World maps, because of their scale, must deal with the problem of projection. Maps rendered in two dimensions by necessity distort the display of the three-dimensional surface of the Earth. While this is true of any map, these distortions reach extremes in a world map. Many techniques have been developed to present world maps that address diverse technical and aesthetic goals.

Charting a world map requires global knowledge of the Earth, its oceans, and its continents. From prehistory through the Middle Ages, creating an accurate world map would have been impossible because less than half of Earth's coastlines and only a small fraction of its continental interiors were known to any culture. With exploration that began during the European Renaissance, knowledge of the Earth's surface accumulated rapidly, such that most of the world's coastlines had been mapped, at least roughly, by the mid-1700s and the continental interiors by the twentieth century.

Spherical Earth or Earth's curvature refers to the approximation of the figure of the Earth as a sphere. The earliest documented mention of the concept dates from around the 5th century BC, when it appears in the writings of Greek philosophers. In the 3rd century BC, Hellenistic astronomy established the roughly spherical shape of Earth as a physical fact and calculated the Earth's circumference. This knowledge was gradually adopted throughout the Old World during Late Antiquity and the Middle Ages, displacing earlier beliefs in a flat Earth. A practical demonstration of Earth's sphericity was achieved by Ferdinand Magellan and Juan Sebastián Elcano's circumnavigation (1519–1522).

The realization that the figure of the Earth is more accurately described as an ellipsoid dates to the 17th century, as described by Isaac Newton in Principia. In the early 19th century, the flattening of the earth ellipsoid was determined to be of the order of 1/300 (Delambre, Everest). The modern value as determined by the US DoD World Geodetic System since the 1960s is close to 1/298.25. The scientific study of the shape of the Earth is known as geodesy.

Arabic is a Central Semitic language of the Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns language codes to 32 varieties of Arabic, including its standard form of Literary Arabic, known as Modern Standard Arabic, which is derived from Classical Arabic. This distinction exists primarily among Western linguists; Arabic speakers themselves generally do not distinguish between Modern Standard Arabic and Classical Arabic, but rather refer to both as al-ʿarabiyyatu l-fuṣḥā (اَلعَرَبِيَّةُ ٱلْفُصْحَىٰ "the eloquent Arabic") or simply al-fuṣḥā (اَلْفُصْحَىٰ).

Arabic is the third most widespread official language after English and French, one of six official languages of the United Nations, and the liturgical language of Islam. Arabic is widely taught in schools and universities around the world and is used to varying degrees in workplaces, governments and the media. During the Middle Ages, Arabic was a major vehicle of culture and learning, especially in science, mathematics and philosophy. As a result, many European languages have borrowed words from it. Arabic influence, mainly in vocabulary, is seen in European languages (mainly Spanish and to a lesser extent Portuguese, Catalan, and Sicilian) owing to the proximity of Europe and the long-lasting Arabic cultural and linguistic presence, mainly in Southern Iberia, during the Al-Andalus era. Maltese is a Semitic language developed from a dialect of Arabic and written in the Latin alphabet. The Balkan languages, including Albanian, Greek, Serbo-Croatian, and Bulgarian, have also acquired many words of Arabic origin, mainly through direct contact with Ottoman Turkish.

The Roman Senate (Latin: Senātus Rōmānus) was the highest and constituting assembly of ancient Rome and its aristocracy. With different powers throughout its existence, it lasted from the first days of the city of Rome (traditionally founded in 753 BC) as the Senate of the Roman Kingdom, to the Senate of the Roman Republic and Senate of the Roman Empire and eventually the Byzantine Senate of the Eastern Roman Empire, existing well into the post-classical era and Middle Ages.

During the days of the Roman Kingdom, the Senate was generally little more than an advisory council to the king. However, as Rome was an electoral monarchy, the Senate also elected new Roman kings. The last king of Rome, Lucius Tarquinius Superbus, was overthrown following a coup d'état led by Lucius Junius Brutus, who founded the Roman Republic. During the early Republic, the Senate was politically weak, while the various executive Roman magistrates who appointed the senators for life (or until expulsion by Roman censors) were quite powerful. Since the transition from monarchy to constitutional rule was most likely gradual, it took several generations before the Senate was able to assert itself over the executive magistrates. By the middle Republic, the Senate had reached the apex of its republican power. The late Republic saw a decline in the Senate's power, which began following the reforms of the tribunes Tiberius and Gaius Gracchus. After the transition of the Republic into the Principate, the Senate lost much of its political power as well as its prestige.