International Date Line
The International Date Line is an imaginary line of demarcation on the surface of Earth that runs from the North Pole to the South Pole and demarcates the change of one calendar day to the next. It passes through the middle of the Pacific Ocean following the 180° line of longitude but deviating to pass around some territories and island groups; this description is based on the most common understanding of the de facto International Date Line. See § De facto and de jure date lines below, map above at right; the IDL is based on the meridian of 180° longitude down the middle of the Pacific Ocean, halfway around the world from the Greenwich meridian. In many places, the IDL follows the 180° meridian exactly. In other places, the IDL deviates east or west away from that meridian; these various deviations accommodate the political and/or economic affiliations of the affected areas. Proceeding from north to south, the first deviation of the IDL from 180° is to pass to the east of Wrangel Island and the Chukchi Peninsula, the easternmost part of Russian Siberia.
It passes through the Bering Strait between the Diomede Islands at a distance of 1.5 kilometres from each island at 168°58′37″ W. It bends west of 180°, passing west of St. Lawrence Island and St. Matthew Island; the IDL crosses between the U. S. Aleutian Islands and the Commander Islands, which belong to Russia, it bends southeast again to return to 180°. Thus, all of Russia is to the west of the IDL, all of the United States is to the east except for the insular areas of Guam, the Northern Mariana Islands, Wake Island; the IDL remains on the 180° meridian until passing the equator. Two US-owned uninhabited atolls, Howland Island and Baker Island, just north of the equator in the central Pacific Ocean, have the latest time on Earth; the IDL circumscribes Kiribati by swinging far to the east reaching the 150°W meridian. Kiribati's easternmost islands, the southern Line Islands south of Hawaii, have the most advanced time on Earth, UTC+14:00 hours. South of Kiribati, the IDL returns westwards but remains east of 180°, passing between Samoa and American Samoa.
In much of this area, the IDL follows the 165°W meridian. Accordingly, Tokelau and Futuna, Tonga and New Zealand's Kermadec Islands and Chatham Islands are all west of the IDL and have the same date. American Samoa, the Cook Islands and French Polynesia are east of the IDL and one day behind; the IDL bends southwest to return to 180°. It follows that meridian until reaching Antarctica. Conventionally, the IDL is not drawn into Antarctica on most maps. A person who goes around the world from east to west would gain or set their clock back one hour for every 15° of longitude crossed, would gain 24 hours for one circuit of the globe from east to west if they did not compensate by setting their clock forward one day when they crossed the IDL. In contrast, a west-to-east circumnavigation of the globe loses an hour for every 15° of longitude crossed but gains back a day when crossing the IDL; the IDL must therefore be observed in conjunction with the Earth's time zones: on crossing it in either direction, the calendar date is adjusted by one day.
For the two hours between 10:00 and 11:59 UTC each day, three different calendar dates are observed at the same time in different places on Earth. For example, at 10:15 UTC Thursday, it is 23:15 Wednesday in American Samoa, Thursday in most of the world, 00:15 Friday in Kiritimati. During the first hour, all three calendar dates include inhabited places. During the second hour one of the calendar dates is limited to an uninhabited maritime time zone twelve hours behind UTC. According to the clock, the first areas to experience a new day and a New Year are islands that use UTC+14:00; these include portions of the Republic of Kiribati, including Millennium Island in the Line Islands, as well as Samoa during the southern summer. The first major cities to experience a new day are New Zealand. A 1994 realignment of the IDL made Caroline Island one of the first points of land on Earth to reach January 1, 2000 on the calendar; as a result, this atoll was renamed Millennium Island. The areas that are the first to see the daylight of a new day vary by the season.
Around the June solstice, the first area would be anyplace within the Kamchatka Time Zone, far enough north to experience midnight sun on the given date. At the equinoxes, the first place to see daylight would be the uninhabited Millennium Island in Kiribati, the easternmost land located west of the IDL. Near the December solstice, the first places would be Antarctic research stations using New Zealand Time during summer that experience midnight sun; these include Amundsen-Scott South Pole Station, McMurdo Station, Scott Base and Mario Zucchelli Station. There are two ways time zones and thereby the location of the International Date Line are determined, one on land and adjacent territorial waters, the other on open seas. All nations unilaterally determine their standard time zones, applicable only on land and adjacent territorial waters; this date line can be called de facto since it is not based on international law, but on national laws. These national zones do not extend into international waters.
The nautical date line, not
Modern history, the modern period or the modern era, is the linear, historiographical approach to the time frame after post-classical history. Modern history can be further broken down into periods: The early modern period began in the early 16th century; the late modern period began in the mid-18th century. It took all of human history up to 1804 for the world's population to reach 1 billion. Contemporary history is the span of historic events from 1945 that are relevant to the present time; this article covers the 1800–1950 time period with a brief summary of 1500–1800. For a more in depth article on modern times before 1800, see Early Modern period. In the pre-modern era, many people's sense of self and purpose was expressed via a faith in some form of deity, be it that in a single God or in many gods. Pre-modern cultures have not been thought of creating a sense of distinct individuality, though. Religious officials, who held positions of power, were the spiritual intermediaries to the common person.
It was only through these intermediaries. Tradition was sacred to ancient cultures and was unchanging and the social order of ceremony and morals in a culture could be enforced; the term modern was coined in the 16th century to indicate recent times. The European Renaissance, which marked the transition between the Late Middle Ages and Early Modern times, started in Italy and was spurred in part by the rediscovery of classical art and literature, as well as the new perspectives gained from the Age of Discovery and the invention of the telescope and microscope, expanding the borders of thought and knowledge. In contrast to the pre-modern era, Western civilization made a gradual transition from pre-modernity to modernity when scientific methods were developed which led many to believe that the use of science would lead to all knowledge, thus throwing back the shroud of myth under which pre-modern peoples lived. New information about the world was discovered via empirical observation, versus the historic use of reason and innate knowledge.
The term Early Modern was introduced in the English language in the 1930s to distinguish the time between what has been called the Middle Ages and time of the late Enlightenment. It is important to note. In usage in other parts of the world, such as in Asia, in Muslim countries, the terms are applied in a different way, but in the context with their contact with European culture in the Age of Discovery. In the Contemporary era, there were various socio-technological trends. Regarding the 21st century and the late modern world, the Information Age and computers were forefront in use, not ubiquitous but present in everyday life; the development of Eastern powers was with China and India becoming more powerful. In the Eurasian theater, the European Union and Russian Federation were two forces developed. A concern for Western world, if not the whole world, was the late modern form of terrorism and the warfare that has resulted from the contemporary terrorist acts; the modern period has been a period of significant development in the fields of science, politics and technology.
It has been an age of discovery and globalization. During this time, the European powers and their colonies, began a political and cultural colonization of the rest of the world. By the late 19th and 20th centuries, modernist art, politics and culture has come to dominate not only Western Europe and North America, but every civilized area on the globe, including movements thought of as opposed to the west and globalization; the modern era is associated with the development of individualism, urbanization and a belief in the possibilities of technological and political progress. Wars and other perceived problems of this era, many of which come from the effects of rapid change, the connected loss of strength of traditional religious and ethical norms, have led to many reactions against modern development. Optimism and belief in constant progress has been most criticized by postmodernism while the dominance of Western Europe and Anglo-America over other continents has been criticized by postcolonial theory.
One common conception of modernity is the condition of Western history since the mid-15th century, or the European development of movable type and the printing press. In this context the "modern" society is said to develop over many periods, to be influenced by important events that represent breaks in the continuity; the modern era includes the early period, called the early modern period, which lasted from c. 1500 to around c. 1800. Particular facets of early modernity include: The Renaissance in Italy The Reformation and Counter Reformation The Age of Discovery The Columbian Exchange and Colonization of the Americas The rise of mercantilism and capitalism The Golden Age of PiracyImportant events in the early modern period include: The spread of the printing press The Thirty Years' War and the Peace of Westphalia in Europe The English Civil War, the Glorious Revolution, the union
A lustrum was a term for a five-year period in Ancient Rome. The lustration was a sacrifice for expiation and purification offered by one of the censors in the name of the Roman people at the close of the taking of the census; the sacrifice was in the form of an animal sacrifice, known as a suovetaurilia. These censuses were taken at five-year intervals, thus a lustrum came to refer to the five-year inter-census period. Lustrum is a lustration or purification of the whole Roman people performed by one of the censors in the Campus Martius, after the taking of the census was over; as this purification took place only once in five years, the word lustrum was used to designate the time between two lustra. The first lustrum was performed in 566 BC by King Servius, after he had completed his census, afterwards it is said to have taken place every five years after the census was over. In the earliest period of the republic, the business of the census and the solemnities of the lustrum were performed by the consuls.
The first censors were appointed in 443 BC, from this year down to 294 BC there had, according to Livy, only been 26 pairs of censors, only 21 lustra, or general purifications, although if all had been regular, there would have been 30 pairs of censors and 30 lustra. Sometimes the census was not held at all, or at least not by the censors; the census might take place without the lustrum, indeed two cases of this kind are recorded, in 459 and 214 BC. In these cases, the lustrum was not performed because of some great calamities that had befallen the republic; the time when the lustrum took place has been calculated. Six ancient Romulian years, of 304 days each, with the difference of two days, equal to five solar years of 365 days each, with one leap year of 366 days; the lustrum, or the great year of the ancient Romans, was thus a cycle, at the end of which, the beginning of the ancient year nearly coincided with that of the solar year. As the coincidence, was not perfect, a month of 24 days was interposed in every eleventh lustrum.
It is probable that the recurrence of such a cycle or great year was, from the earliest times, solemnized with sacrifices and purifications, that King Servius did not introduce them, but connected them with his census, thus set the example for subsequent ages, which however, as we have seen, was not observed with regularity. The last lustrum was solemnized in AD 74, in the reign of Vespasian; the word should not be confused with the identically spelled, but differently pronounced, lustrum, a haunt of wild beasts, plural lustra, a den of vice. Lustratio Decade Century Millennium Livius.org Lustrum
Ancient history as a term refers to the aggregate of past events from the beginning of writing and recorded human history and extending as far as the post-classical history. The phrase may be used either to refer to the period of the academic discipline; the span of recorded history is 5,000 years, beginning with Sumerian Cuneiform script. Ancient History covers all continents inhabited by humans in the 3,000 BC – 500 AD period; the broad term Ancient History is not to be confused with Classical Antiquity. The term classical antiquity is used to refer to Western History in the Ancient Mediterranean from the beginning of recorded Greek history in 776 BC; this coincides with the traditional date of the Founding of Rome in 753 BC, the beginning of the history of ancient Rome, the beginning of the Archaic period in Ancient Greece. The academic term "history" is not to be confused with colloquial references to times past. History is fundamentally the study of the past through documents, can be either scientific or humanistic.
Although the ending date of ancient history is disputed, some Western scholars use the fall of the Western Roman Empire in 476 AD, the closure of the Platonic Academy in 529 AD, the death of the emperor Justinian I in 565 AD, the coming of Islam or the rise of Charlemagne as the end of ancient and Classical European history. Outside of Europe the 450-500 time frame for the end of ancient times has had difficulty as a transition date from Ancient to Post-Classical times. During the time period of'Ancient History', starting from 3000 BC world population was exponentially increasing due to the Neolithic Revolution, in full progress. According to HYDE estimates from the Netherlands world population increased exponentially in this period. In 10,000 BC in Prehistory world population had stood at 2 million, rising to 45 million by 3,000 BC. By the rise of the Iron Age in 1,000 BC that population had risen to 72 million. By the end of the period in 500 AD world population stood at 209 million. In 3,500 years, world population increased by 100 times.
Historians have two major avenues which they take to better understand the ancient world: archaeology and the study of source texts. Primary sources are those sources closest to the origin of the idea under study. Primary sources have been distinguished from secondary sources, which cite, comment on, or build upon primary sources. Archaeology is the excavation and study of artifacts in an effort to interpret and reconstruct past human behavior. Archaeologists excavate the ruins of ancient cities looking for clues as to how the people of the time period lived; some important discoveries by archaeologists studying ancient history include: The Egyptian pyramids: giant tombs built by the ancient Egyptians beginning about 2600 BC as the final resting places of their royalty. The study of the ancient cities of Harappa, Mohenjo-daro, Lothal in India; the city of Pompeii: an ancient Roman city preserved by the eruption of a volcano in AD 79. Its state of preservation is so great that it is a valuable window into Roman culture and provided insight into the cultures of the Etruscans and the Samnites.
The Terracotta Army: the mausoleum of the First Qin Emperor in ancient China. The discovery of Knossos by Minos Kalokairinos and Sir Arthur Evans; the discovery of Troy by Heinrich Schliemann. Most of what is known of the ancient world comes from the accounts of antiquity's own historians. Although it is important to take into account the bias of each ancient author, their accounts are the basis for our understanding of the ancient past; some of the more notable ancient writers include Herodotus, Arrian, Polybius, Sima Qian, Livy, Josephus and Tacitus. A fundamental difficulty of studying ancient history is that recorded histories cannot document the entirety of human events, only a fraction of those documents have survived into the present day. Furthermore, the reliability of the information obtained from these surviving records must be considered. Few people were capable of writing histories, as literacy was not widespread in any culture until long after the end of ancient history; the earliest known systematic historical thought emerged in ancient Greece, beginning with Herodotus of Halicarnassus.
Thucydides eliminated divine causality in his account of the war between Athens and Sparta, establishing a rationalistic element which set a precedent for subsequent Western historical writings. He was the first to distinguish between cause and immediate origins of an event; the Roman Empire was an ancient culture with a high literacy rate, but many works by its most read historians are lost. For example, Livy, a Roman historian who lived in the 1st century BC, wrote a history of Rome called Ab Urbe Condita in 144 volumes. Indeed, only a minority of the work of any major Roman historian has survived. Click the above link to find a listed timeline that provides an overview for Ancient History, its context ranges from 3200 BC to 400 AD. Prehistory is the period before written history; the early human migrations in the Lower Paleolithic saw Homo erectus spread across Eurasia 1.8 million years ago. The controlled use of fire occurred 800,000 years ago in the Middle Paleolithic. 250,000 years ago, Homo sapiens emerged in Africa.
60–70,000 years ago, Homo sapiens migrated out of Africa along a coastal route to South and So
Italian six-hour clock
The six-hour clock called the Roman or the Italian system, is a timekeeping system used in Italy. In this system, the day starts at the evening Ave Maria at the end of twilight half an hour after sunset, the following 24 hours are divided into four cycles of six hours each. Introduced by the Catholic Church in the 13th century, it remained in use in Italy until superseded by the 12-hour clock following the Napoleonic invasion of Italy. 12-hour clock 24-hour clock Date and time notation in Italy The Thai six-hour clock, another six-hour system. Time in Italy Severino, Nicola, La misteriosa storia degli orologi a sei ore
Time is the indefinite continued progress of existence and events that occur in irreversible succession through the past, in the present, the future. Time is a component quantity of various measurements used to sequence events, to compare the duration of events or the intervals between them, to quantify rates of change of quantities in material reality or in the conscious experience. Time is referred to as a fourth dimension, along with three spatial dimensions. Time has long been an important subject of study in religion and science, but defining it in a manner applicable to all fields without circularity has eluded scholars. Diverse fields such as business, sports, the sciences, the performing arts all incorporate some notion of time into their respective measuring systems. Time in physics is unambiguously operationally defined as "what a clock reads". See Units of Time. Time is one of the seven fundamental physical quantities in both the International System of Units and International System of Quantities.
Time is used to define other quantities – such as velocity – so defining time in terms of such quantities would result in circularity of definition. An operational definition of time, wherein one says that observing a certain number of repetitions of one or another standard cyclical event constitutes one standard unit such as the second, is useful in the conduct of both advanced experiments and everyday affairs of life; the operational definition leaves aside the question whether there is something called time, apart from the counting activity just mentioned, that flows and that can be measured. Investigations of a single continuum called spacetime bring questions about space into questions about time, questions that have their roots in the works of early students of natural philosophy. Temporal measurement has occupied scientists and technologists, was a prime motivation in navigation and astronomy. Periodic events and periodic motion have long served as standards for units of time. Examples include the apparent motion of the sun across the sky, the phases of the moon, the swing of a pendulum, the beat of a heart.
The international unit of time, the second, is defined by measuring the electronic transition frequency of caesium atoms. Time is of significant social importance, having economic value as well as personal value, due to an awareness of the limited time in each day and in human life spans. Speaking, methods of temporal measurement, or chronometry, take two distinct forms: the calendar, a mathematical tool for organising intervals of time, the clock, a physical mechanism that counts the passage of time. In day-to-day life, the clock is consulted for periods less than a day whereas the calendar is consulted for periods longer than a day. Personal electronic devices display both calendars and clocks simultaneously; the number that marks the occurrence of a specified event as to hour or date is obtained by counting from a fiducial epoch – a central reference point. Artifacts from the Paleolithic suggest that the moon was used to reckon time as early as 6,000 years ago. Lunar calendars were among the first to appear, with years of either 13 lunar months.
Without intercalation to add days or months to some years, seasons drift in a calendar based on twelve lunar months. Lunisolar calendars have a thirteenth month added to some years to make up for the difference between a full year and a year of just twelve lunar months; the numbers twelve and thirteen came to feature prominently in many cultures, at least due to this relationship of months to years. Other early forms of calendars originated in Mesoamerica in ancient Mayan civilization; these calendars were religiously and astronomically based, with 18 months in a year and 20 days in a month, plus five epagomenal days at the end of the year. The reforms of Julius Caesar in 45 BC put the Roman world on a solar calendar; this Julian calendar was faulty in that its intercalation still allowed the astronomical solstices and equinoxes to advance against it by about 11 minutes per year. Pope Gregory XIII introduced a correction in 1582. During the French Revolution, a new clock and calendar were invented in attempt to de-Christianize time and create a more rational system in order to replace the Gregorian calendar.
The French Republican Calendar's days consisted of ten hours of a hundred minutes of a hundred seconds, which marked a deviation from the 12-based duodecimal system used in many other devices by many cultures. The system was abolished in 1806. A large variety of devices have been invented to measure time; the study of these devices is called horology. An Egyptian device that dates to c. 1500 BC, similar in shape to a bent T-square, measured the passage of time from the shadow cast by its crossbar on a nonlinear rule. The T was oriented eastward in the mornings. At noon, the device was turned around so. A sundial uses a gnomon to cast a shadow on a set of markings calibrated to the hour; the position of the shadow marks the hour in local time. The idea to separate the day into smaller parts is credited to Egyptians because of their sundials, which operated on a duodecimal system; the importance of the number 12 is due to the number of lunar cycles in a year and the number of stars used to count the passage of night.
The most precise timekeeping device of the ancient