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X-ray photon correlation spectroscopy

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109-403: X-ray photon correlation spectroscopy (XPCS) in physics and chemistry , is a novel technique that exploits a coherent X-ray synchrotron beam to measure the dynamics of a sample. By recording how a coherent speckle pattern fluctuates in time, one can measure a time correlation function, and thus measure the timescale processes of interest (diffusion, relaxation, reorganization, etc.). XPCS

218-499: A Platonist by Stephen Hawking , a view Penrose discusses in his book, The Road to Reality . Hawking referred to himself as an "unashamed reductionist" and took issue with Penrose's views. Mathematics provides a compact and exact language used to describe the order in nature. This was noted and advocated by Pythagoras , Plato , Galileo, and Newton. Some theorists, like Hilary Putnam and Penelope Maddy , hold that logical truths, and therefore mathematical reasoning, depend on

327-488: A frame of reference that is in motion with respect to an observer; the special theory of relativity is concerned with motion in the absence of gravitational fields and the general theory of relativity with motion and its connection with gravitation . Both quantum theory and the theory of relativity find applications in many areas of modern physics. While physics itself aims to discover universal laws, its theories lie in explicit domains of applicability. Loosely speaking,

436-415: A speckle pattern by the scattered coherent light originating from a material where some spatial inhomogeneities are present. A speckle pattern is a diffraction limited structure factor, and is typically observed when laser light is reflected from a rough surface, or from dust particles performing Brownian motion in air. The observation of speckle patterns with hard X-rays has just been demonstrated in

545-540: A "Sumerian renaissance" in the past. Already, the region was becoming more Semitic than Sumerian, with the resurgence of the Akkadian-speaking Semites in Assyria and elsewhere, and the influx of waves of Semitic Martu ( Amorites ), who founded several competing local powers in the south, including Isin , Larsa , Eshnunna and later, Babylonia. The last of these eventually came to briefly dominate

654-455: A basic awareness of the motions of the Sun, Moon, and stars. The stars and planets, believed to represent gods, were often worshipped. While the explanations for the observed positions of the stars were often unscientific and lacking in evidence, these early observations laid the foundation for later astronomy, as the stars were found to traverse great circles across the sky, which could not explain

763-651: A century in the Third Dynasty of Ur at approximately 2100–2000 BC, but the Akkadian language also remained in use for some time. The Sumerians were entirely unknown during the early period of modern archeology. Jules Oppert was the first scholar to publish the word Sumer in a lecture on 17 January 1869. The first major excavations of Sumerian cities were in 1877 at Girsu by the French archeologist Ernest de Sarzec , in 1889 at Nippur by John Punnett Peters from

872-598: A difficult environment. Others have suggested a continuity of Sumerians, from the indigenous hunter-fisherfolk traditions, associated with the bifacial assemblages found on the Arabian littoral. Juris Zarins believes the Sumerians may have been the people living in the Persian Gulf region before it flooded at the end of the last Ice Age. In the early Sumerian period, the primitive pictograms suggest that There

981-420: A hard-to-find physical meaning. The final mathematical solution has an easier-to-find meaning, because it is what the solver is looking for. Physics is a branch of fundamental science (also called basic science). Physics is also called " the fundamental science" because all branches of natural science including chemistry, astronomy, geology, and biology are constrained by laws of physics. Similarly, chemistry

1090-465: A specific practical application as a goal, other than the deeper insight into the phenomema themselves. Applied physics is a general term for physics research and development that is intended for a particular use. An applied physics curriculum usually contains a few classes in an applied discipline, like geology or electrical engineering. It usually differs from engineering in that an applied physicist may not be designing something in particular, but rather

1199-426: A speed much less than the speed of light. These theories continue to be areas of active research today. Chaos theory , an aspect of classical mechanics, was discovered in the 20th century, three centuries after the original formulation of classical mechanics by Newton (1642–1727). These central theories are important tools for research into more specialized topics, and any physicist, regardless of their specialization,

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1308-399: A subfield of mechanics , is used in the building of bridges and other static structures. The understanding and use of acoustics results in sound control and better concert halls; similarly, the use of optics creates better optical devices. An understanding of physics makes for more realistic flight simulators , video games, and movies, and is often critical in forensic investigations. With

1417-466: A substantial treatise on " Physics " – in the 4th century BC. Aristotelian physics was influential for about two millennia. His approach mixed some limited observation with logical deductive arguments, but did not rely on experimental verification of deduced statements. Aristotle's foundational work in Physics, though very imperfect, formed a framework against which later thinkers further developed

1526-413: Is clear-cut, but not always obvious. For example, mathematical physics is the application of mathematics in physics. Its methods are mathematical, but its subject is physical. The problems in this field start with a " mathematical model of a physical situation " (system) and a "mathematical description of a physical law" that will be applied to that system. Every mathematical statement used for solving has

1635-419: Is concerned with bodies acted on by forces and bodies in motion and may be divided into statics (study of the forces on a body or bodies not subject to an acceleration), kinematics (study of motion without regard to its causes), and dynamics (study of motion and the forces that affect it); mechanics may also be divided into solid mechanics and fluid mechanics (known together as continuum mechanics ),

1744-400: Is concerned with the most basic units of matter; this branch of physics is also known as high-energy physics because of the extremely high energies necessary to produce many types of particles in particle accelerators . On this scale, ordinary, commonsensical notions of space, time, matter, and energy are no longer valid. The two chief theories of modern physics present a different picture of

1853-587: Is considerable evidence concerning Sumerian music . Lyres and flutes were played, among the best-known examples being the Lyres of Ur . Sumerian culture was male-dominated and stratified. The Code of Ur-Nammu , the oldest such codification yet discovered, dating to the Ur III, reveals a glimpse at societal structure in late Sumerian law. Beneath the lu-gal ("great man" or king), all members of society belonged to one of two basic strata: The " lu " or free person, and

1962-425: Is expected to be literate in them. These include classical mechanics, quantum mechanics, thermodynamics and statistical mechanics , electromagnetism , and special relativity. Classical physics includes the traditional branches and topics that were recognized and well-developed before the beginning of the 20th century—classical mechanics, acoustics , optics , thermodynamics, and electromagnetism. Classical mechanics

2071-569: Is first attested in proper names of the kings of Kish c.  2800 BC , preserved in later king lists. There are texts written entirely in Old Akkadian dating from c.  2500 BC . Use of Old Akkadian was at its peak during the rule of Sargon the Great ( c.  2334 –2279 BC), but even then most administrative tablets continued to be written in Sumerian, the language used by

2180-429: Is generally concerned with matter and energy on the normal scale of observation, while much of modern physics is concerned with the behavior of matter and energy under extreme conditions or on a very large or very small scale. For example, atomic and nuclear physics study matter on the smallest scale at which chemical elements can be identified. The physics of elementary particles is on an even smaller scale since it

2289-407: Is little break in historical continuity between the pre- and post-Sargon periods, and that too much emphasis has been placed on the perception of a "Semitic vs. Sumerian" conflict. It is certain that Akkadian was also briefly imposed on neighboring parts of Elam that were previously conquered, by Sargon. c. 2193–2119 BC (middle chronology) c.  2200 –2110 BC (middle chronology) Following

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2398-526: Is marked by a distinctive style of fine quality painted pottery which spread throughout Mesopotamia and the Persian Gulf . The oldest evidence for occupation comes from Tell el-'Oueili , but, given that environmental conditions in southern Mesopotamia were favourable to human occupation well before the Ubaid period, it is likely that older sites exist but have not yet been found. It appears that this culture

2507-404: Is most clearly seen at Tell el-'Oueili near Larsa , excavated by the French in the 1980s, where eight levels yielded pre-Ubaid pottery resembling Samarran ware. According to this theory, farming peoples spread down into southern Mesopotamia because they had developed a temple-centered social organization for mobilizing labor and technology for water control, enabling them to survive and prosper in

2616-593: Is often called the central science because of its role in linking the physical sciences. For example, chemistry studies properties, structures, and reactions of matter (chemistry's focus on the molecular and atomic scale distinguishes it from physics ). Structures are formed because particles exert electrical forces on each other, properties include physical characteristics of given substances, and reactions are bound by laws of physics, like conservation of energy , mass , and charge . Fundamental physics seeks to better explain and understand phenomena in all spheres, without

2725-506: Is possible only in discrete steps proportional to their frequency. This, along with the photoelectric effect and a complete theory predicting discrete energy levels of electron orbitals , led to the theory of quantum mechanics improving on classical physics at very small scales. Quantum mechanics would come to be pioneered by Werner Heisenberg , Erwin Schrödinger and Paul Dirac . From this early work, and work in related fields,

2834-663: Is the earliest known civilization , located in the historical region of southern Mesopotamia (now south-central Iraq ), emerging during the Chalcolithic and early Bronze Ages between the sixth and fifth millennium BC. Like nearby Elam , it is one of the cradles of civilization , along with Egypt , the Indus Valley , the Erligang culture of the Yellow River valley, Caral-Supe , and Mesoamerica . Living along

2943-409: Is used to study the slow dynamics of various equilibrium and non-equilibrium processes occurring in condensed matter systems. XPCS experiments have the advantage of providing information of dynamical properties of materials (e.g. vitreous materials), while other experimental techniques can only provide information about the static structure of the material. This technique is based on the generation of

3052-431: Is using physics or conducting physics research with the aim of developing new technologies or solving a problem. The approach is similar to that of applied mathematics . Applied physicists use physics in scientific research. For instance, people working on accelerator physics might seek to build better particle detectors for research in theoretical physics. Physics is used heavily in engineering. For example, statics,

3161-532: The Akkadian name for the "Sumerians", the ancient non- Semitic -speaking inhabitants of southern Mesopotamia . In their inscriptions, the Sumerians called their land "Kengir", the "Country of the noble lords" ( Sumerian : 𒆠 𒂗 𒄀 , romanized:  ki-en-gi(-r) , lit.   ''country" + "lords" + "noble''), and their language "Emegir" ( Sumerian : 𒅴𒂠 , romanized:  eme-g̃ir or 𒅴𒄀 eme-gi 15 ). The origin of

3270-536: The Industrial Revolution as energy needs increased. The laws comprising classical physics remain widely used for objects on everyday scales travelling at non-relativistic speeds, since they provide a close approximation in such situations, and theories such as quantum mechanics and the theory of relativity simplify to their classical equivalents at such scales. Inaccuracies in classical mechanics for very small objects and very high velocities led to

3379-660: The Latin physica ('study of nature'), which itself is a borrowing of the Greek φυσική ( phusikḗ 'natural science'), a term derived from φύσις ( phúsis 'origin, nature, property'). Astronomy is one of the oldest natural sciences . Early civilizations dating before 3000 BCE, such as the Sumerians , ancient Egyptians , and the Indus Valley Civilisation , had a predictive knowledge and

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3488-585: The Middle East and were responsible for the spread of farming in the Middle East. However, contrary evidence strongly suggests that the first farming originated in the Fertile Crescent . Although not specifically discussing Sumerians, Lazaridis et al. 2016 have suggested a partial North African origin for some pre-Semitic cultures of the Middle East, particularly Natufians , after testing

3597-608: The Northern Hemisphere . Natural philosophy has its origins in Greece during the Archaic period (650 BCE – 480 BCE), when pre-Socratic philosophers like Thales rejected non-naturalistic explanations for natural phenomena and proclaimed that every event had a natural cause. They proposed ideas verified by reason and observation, and many of their hypotheses proved successful in experiment; for example, atomism

3706-637: The Scientific Revolution in the 17th century, these natural sciences branched into separate research endeavors. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry , and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in these and other academic disciplines such as mathematics and philosophy. Advances in physics often enable new technologies . For example, advances in

3815-619: The Standard Model of particle physics was derived. Following the discovery of a particle with properties consistent with the Higgs boson at CERN in 2012, all fundamental particles predicted by the standard model, and no others, appear to exist; however, physics beyond the Standard Model , with theories such as supersymmetry , is an active area of research. Areas of mathematics in general are important to this field, such as

3924-531: The University of Pennsylvania between 1889 and 1900, and in Shuruppak by German archeologist Robert Koldewey in 1902–1903. Major publications of these finds were " Decouvertes en Chaldée par Ernest de Sarzec " by Léon Heuzey in 1884, " Les Inscriptions de Sumer et d'Akkad " by François Thureau-Dangin in 1905, and " Grundzüge der sumerischen Grammatik " on Sumerian grammar by Arno Poebel in 1923. In

4033-558: The archaeological record shows clear uninterrupted cultural continuity from the time of the early Ubaid period (5300–4700 BC C-14 ) settlements in southern Mesopotamia. The Sumerian people who settled here, farmed the lands in this region that were made fertile by silt deposited by the Tigris and the Euphrates . Some archaeologists have speculated that the original speakers of ancient Sumerian may have been farmers, who moved down from

4142-439: The camera obscura (his thousand-year-old version of the pinhole camera ) and delved further into the way the eye itself works. Using the knowledge of previous scholars, he began to explain how light enters the eye. He asserted that the light ray is focused, but the actual explanation of how light projected to the back of the eye had to wait until 1604. His Treatise on Light explained the camera obscura , hundreds of years before

4251-579: The empirical world. This is usually combined with the claim that the laws of logic express universal regularities found in the structural features of the world, which may explain the peculiar relation between these fields. Physics uses mathematics to organise and formulate experimental results. From those results, precise or estimated solutions are obtained, or quantitative results, from which new predictions can be made and experimentally confirmed or negated. The results from physics experiments are numerical data, with their units of measure and estimates of

4360-543: The standard consensus that the laws of physics are universal and do not change with time, physics can be used to study things that would ordinarily be mired in uncertainty . For example, in the study of the origin of the Earth, a physicist can reasonably model Earth's mass, temperature, and rate of rotation, as a function of time allowing the extrapolation forward or backward in time and so predict future or prior events. It also allows for simulations in engineering that speed up

4469-415: The " Dynasty of Isin " in the Sumerian king list, ending with the rise of Babylonia under Hammurabi c. 1800 BC. Later rulers who dominated Assyria and Babylonia occasionally assumed the old Sargonic title "King of Sumer and Akkad", such as Tukulti-Ninurta I of Assyria after c. 1225 BC. Uruk, one of Sumer's largest cities, has been estimated to have had a population of 50,000–80,000 at its height. Given

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4578-435: The 16th and 17th centuries, and Isaac Newton 's discovery and unification of the laws of motion and universal gravitation (that would come to bear his name). Newton also developed calculus , the mathematical study of continuous change, which provided new mathematical methods for solving physical problems. The discovery of laws in thermodynamics , chemistry , and electromagnetics resulted from research efforts during

4687-435: The Akkadian and Ur III phases, there was a shift from the cultivation of wheat to the more salt-tolerant barley , but this was insufficient, and during the period from 2100 BC to 1700 BC, it is estimated that the population in this area declined by nearly three-fifths. This greatly upset the balance of power within the region, weakening the areas where Sumerian was spoken, and comparatively strengthening those where Akkadian

4796-528: The Sumerian king list whose name is known from any other legendary source is Etana , 13th king of the first dynasty of Kish . The earliest king authenticated through archaeological evidence is Enmebaragesi of Kish (Early Dynastic I), whose name is mentioned in the Epic of Gilgamesh —leading to the suggestion that Gilgamesh himself might have been a historical king of Uruk. As the Epic of Gilgamesh shows, this period

4905-421: The Sumerians is not known, but the people of Sumer referred to themselves as "Black-Headed Ones" or "Black-Headed People" ( Sumerian : 𒊕 𒈪 , romanized:  sag̃-gíg , lit.   ''head" + "black'', or 𒊕 𒈪 𒂵 , sag̃-gíg-ga , phonetically /saŋ ɡi ɡa/ , lit. "head" + "black" + relative marker). For example, the Sumerian king Shulgi described himself as "the king of

5014-767: The Sumerians’ sphere of influence (ordered from south to north): Apart from Mari, which lies full 330 kilometres (205 miles) north-west of Agade, but which is credited in the king list as having exercised kingship in the Early Dynastic II period, and Nagar, an outpost, these cities are all in the Euphrates-Tigris alluvial plain, south of Baghdad in what are now the Bābil , Diyala , Wāsit , Dhi Qar , Basra , Al-Muthannā and Al-Qādisiyyah governorates of Iraq . The Sumerian city-states rose to power during

5123-473: The Ubaid period to the Uruk period is marked by a gradual shift from painted pottery domestically produced on a slow wheel to a great variety of unpainted pottery mass-produced by specialists on fast wheels. The Uruk period is a continuation and an outgrowth of Ubaid with pottery being the main visible change. By the time of the Uruk period, c. 4100–2900 BC calibrated, the volume of trade goods transported along

5232-509: The Uruk period coincided with the Piora oscillation , a dry period from c. 3200–2900 BC that marked the end of a long wetter, warmer climate period from about 9,000 to 5,000 years ago, called the Holocene climatic optimum . The dynastic period begins c. 2900 BC and was associated with a shift from the temple establishment headed by council of elders led by a priestly "En" (a male figure when it

5341-422: The Uruk period were probably theocratic and were most likely headed by a priest-king ( ensi ), assisted by a council of elders, including both men and women. It is quite possible that the later Sumerian pantheon was modeled upon this political structure. There was little evidence of organized warfare or professional soldiers during the Uruk period, and towns were generally unwalled. During this period Uruk became

5450-511: The attacks from invaders and continued to advance various fields of learning, including physics. In the sixth century, Isidore of Miletus created an important compilation of Archimedes ' works that are copied in the Archimedes Palimpsest . In sixth-century Europe John Philoponus , a Byzantine scholar, questioned Aristotle 's teaching of physics and noted its flaws. He introduced the theory of impetus . Aristotle's physics

5559-430: The canals and rivers of southern Mesopotamia facilitated the rise of many large, stratified , temple-centered cities, with populations of over 10,000 people, where centralized administrations employed specialized workers. It is fairly certain that it was during the Uruk period that Sumerian cities began to make use of slave labour captured from the hill country, and there is ample evidence for captured slaves as workers in

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5668-434: The concepts of space, time, and matter from that presented by classical physics. Classical mechanics approximates nature as continuous, while quantum theory is concerned with the discrete nature of many phenomena at the atomic and subatomic level and with the complementary aspects of particles and waves in the description of such phenomena. The theory of relativity is concerned with the description of phenomena that take place in

5777-409: The constant speed predicted by Maxwell's equations of electromagnetism. This discrepancy was corrected by Einstein's theory of special relativity , which replaced classical mechanics for fast-moving bodies and allowed for a constant speed of light. Black-body radiation provided another problem for classical physics, which was corrected when Planck proposed that the excitation of material oscillators

5886-466: The development of a new technology. There is also considerable interdisciplinarity , so many other important fields are influenced by physics (e.g., the fields of econophysics and sociophysics ). Physicists use the scientific method to test the validity of a physical theory . By using a methodical approach to compare the implications of a theory with the conclusions drawn from its related experiments and observations, physicists are better able to test

5995-429: The development of modern physics in the 20th century. Modern physics began in the early 20th century with the work of Max Planck in quantum theory and Albert Einstein 's theory of relativity. Both of these theories came about due to inaccuracies in classical mechanics in certain situations. Classical mechanics predicted that the speed of light depends on the motion of the observer, which could not be resolved with

6104-407: The development of new experiments (and often related equipment). Physicists who work at the interplay of theory and experiment are called phenomenologists , who study complex phenomena observed in experiment and work to relate them to a fundamental theory . Theoretical physics has historically taken inspiration from philosophy; electromagnetism was unified this way. Beyond the known universe,

6213-718: The downfall of the Akkadian Empire at the hands of Gutians , another native Sumerian ruler, Gudea of Lagash, rose to local prominence and continued the practices of the Sargonic kings ' claims to divinity. The previous Lagash dynasty, Gudea and his descendants also promoted artistic development and left a large number of archaeological artifacts. Later, the Third Dynasty of Ur under Ur-Nammu and Shulgi (c. 2112–2004 BC, middle chronology), whose power extended as far as southern Assyria , has been erroneously called

6322-754: The earliest texts. Artifacts, and even colonies of this Uruk civilization have been found over a wide area—from the Taurus Mountains in Turkey , to the Mediterranean Sea in the west, and as far east as western Iran . The Uruk period civilization, exported by Sumerian traders and colonists, like that found at Tell Brak , had an effect on all surrounding peoples, who gradually evolved their own comparable, competing economies and cultures. The cities of Sumer could not maintain remote, long-distance colonies by military force. Sumerian cities during

6431-682: The errors in the measurements. Technologies based on mathematics, like computation have made computational physics an active area of research. Ontology is a prerequisite for physics, but not for mathematics. It means physics is ultimately concerned with descriptions of the real world, while mathematics is concerned with abstract patterns, even beyond the real world. Thus physics statements are synthetic, while mathematical statements are analytic. Mathematics contains hypotheses, while physics contains theories. Mathematics statements have to be only logically true, while predictions of physics statements must match observed and experimental data. The distinction

6540-873: The field of theoretical physics also deals with hypothetical issues, such as parallel universes , a multiverse , and higher dimensions . Theorists invoke these ideas in hopes of solving particular problems with existing theories; they then explore the consequences of these ideas and work toward making testable predictions. Experimental physics expands, and is expanded by, engineering and technology. Experimental physicists who are involved in basic research design and perform experiments with equipment such as particle accelerators and lasers , whereas those involved in applied research often work in industry, developing technologies such as magnetic resonance imaging (MRI) and transistors . Feynman has noted that experimentalists may seek areas that have not been explored well by theorists. Sumer Sumer ( / ˈ s uː m ər / )

6649-415: The field. His approach is entirely superseded today. He explained ideas such as motion (and gravity ) with the theory of four elements . Aristotle believed that each of the four classical elements (air, fire, water, earth) had its own natural place. Because of their differing densities, each element will revert to its own specific place in the atmosphere. So, because of their weights, fire would be at

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6758-471: The first empires known to history was that of Eannatum of Lagash, who annexed practically all of Sumer, including Kish, Uruk, Ur , and Larsa , and reduced to tribute the city-state of Umma , arch-rival of Lagash. In addition, his realm extended to parts of Elam and along the Persian Gulf . He seems to have used terror as a matter of policy. Eannatum's Stele of the Vultures depicts vultures pecking at

6867-540: The first state that successfully united larger parts of Mesopotamia in the 23rd century BC. After the Gutian period , the Ur III kingdom similarly united parts of northern and southern Mesopotamia. It ended in the face of Amorite incursions at the beginning of the second millennium BC. The Amorite "dynasty of Isin " persisted until c.  1700 BC , when Mesopotamia was united under Babylonian rule. The Ubaid period

6976-739: The four quarters, the pastor of the black-headed people". The Akkadians also called the Sumerians "black-headed people", or ṣalmat-qaqqadi , in the Semitic Akkadian language. The Akkadians, the East Semitic-speaking people who later conquered the Sumerian city-states , gave Sumer its main historical name, but the phonological development of the term šumerû is uncertain. Hebrew שִׁנְעָר Šinʿar , Egyptian Sngr , and Hittite Šanhar(a) , all referring to southern Mesopotamia, could be western variants of Sumer . Most historians have suggested that Sumer

7085-576: The genomes of Natufian and Pre-Pottery Neolithic culture-bearers. Craniometric analysis has also suggested an affinity between Natufians and ancient North Africans. Some scholars associate the Sumerians with the Hurrians and Urartians , and suggest the Caucasus as their homeland. This is not generally accepted. Based on mentions of Dilmun as the “home city of the land of Sumer” in Sumerian legends and literature, other scholars have suggested

7194-471: The idea of a Proto-Euphratean language or one substrate language; they think the Sumerian language may originally have been that of the hunting and fishing peoples who lived in the marshland and the Eastern Arabia littoral region and were part of the Arabian bifacial culture. Juris Zarins believes the Sumerians lived along the coast of Eastern Arabia , today's Persian Gulf region, before it

7303-438: The last few years. This observation is only possible now because of the development of new synchrotron radiation X-ray sources that can provide sufficient coherent flux . A specific subgroup of these techniques is atomic-scale X-ray photon correlation spectroscopy (aXPCS). Physics Physics is the scientific study of matter , its fundamental constituents , its motion and behavior through space and time , and

7412-514: The late 4th millennium BC, Sumer was divided into many independent city-states , which were divided by canals and boundary stones. Each was centered on a temple dedicated to the particular patron god or goddess of the city and ruled over by a priestly governor ( ensi ) or by a king ( lugal ) who was intimately tied to the city's religious rites. An incomplete list of cities that may have been visited, interacted and traded with, invaded, conquered, destroyed, occupied, colonized by and/or otherwise within

7521-400: The latter include such branches as hydrostatics , hydrodynamics and pneumatics . Acoustics is the study of how sound is produced, controlled, transmitted and received. Important modern branches of acoustics include ultrasonics , the study of sound waves of very high frequency beyond the range of human hearing; bioacoustics , the physics of animal calls and hearing, and electroacoustics ,

7630-490: The laws of classical physics accurately describe systems whose important length scales are greater than the atomic scale and whose motions are much slower than the speed of light. Outside of this domain, observations do not match predictions provided by classical mechanics. Einstein contributed the framework of special relativity, which replaced notions of absolute time and space with spacetime and allowed an accurate description of systems whose components have speeds approaching

7739-412: The manipulation of audible sound waves using electronics. Optics, the study of light, is concerned not only with visible light but also with infrared and ultraviolet radiation , which exhibit all of the phenomena of visible light except visibility, e.g., reflection, refraction, interference, diffraction, dispersion, and polarization of light. Heat is a form of energy, the internal energy possessed by

7848-489: The marshlands, who may have been the ancestors of the Sumerians. Reliable historical records begin with Enmebaragesi ( Early Dynastic I ). The Sumerians progressively lost control to Semitic states from the northwest. Sumer was conquered by the Semitic-speaking kings of the Akkadian Empire around 2270 BC ( short chronology ), but Sumerian continued as a sacred language . Native Sumerian rule re-emerged for about

7957-704: The modern development of photography. The seven-volume Book of Optics ( Kitab al-Manathir ) influenced thinking across disciplines from the theory of visual perception to the nature of perspective in medieval art, in both the East and the West, for more than 600 years. This included later European scholars and fellow polymaths, from Robert Grosseteste and Leonardo da Vinci to Johannes Kepler . The translation of The Book of Optics had an impact on Europe. From it, later European scholars were able to build devices that replicated those Ibn al-Haytham had built and understand

8066-429: The most urbanized city in the world, surpassing for the first time 50,000 inhabitants. The ancient Sumerian king list includes the early dynasties of several prominent cities from this period. The first set of names on the list is of kings said to have reigned before a major flood occurred. These early names may be fictional, and include some legendary and mythological figures, such as Alulim and Dumizid . The end of

8175-467: The north of Mesopotamia after perfecting irrigation agriculture there. The Ubaid period pottery of southern Mesopotamia has been connected via Choga Mami transitional ware, to the pottery of the Samarra period culture ( c.  5700 –4900 BC C-14 ) in the north, who were the first to practice a primitive form of irrigation agriculture along the middle Tigris River and its tributaries. The connection

8284-402: The north. Ecologically, the agricultural productivity of the Sumerian lands was being compromised as a result of rising salinity. Soil salinity in this region had been long recognized as a major problem. Poorly drained irrigated soils, in an arid climate with high levels of evaporation, led to the buildup of dissolved salts in the soil, eventually reducing agricultural yields severely. During

8393-410: The other Philoponus' criticism of Aristotelian principles of physics served as an inspiration for Galileo Galilei ten centuries later, during the Scientific Revolution . Galileo cited Philoponus substantially in his works when arguing that Aristotelian physics was flawed. In the 1300s Jean Buridan , a teacher in the faculty of arts at the University of Paris , developed the concept of impetus. It

8502-551: The other cities in Sumer, and the large agricultural population, a rough estimate for Sumer's population might be 0.8 million to 1.5 million. The world population at this time has been estimated at 27 million. The Sumerians spoke a language isolate . A number of linguists have claimed to be able to detect a substrate language of unknown classification beneath Sumerian, because names of some of Sumer's major cities are not Sumerian, revealing influences of earlier inhabitants. However,

8611-459: The other, you will see that the ratio of the times required for the motion does not depend on the ratio of the weights, but that the difference in time is a very small one. And so, if the difference in the weights is not considerable, that is, of one is, let us say, double the other, there will be no difference, or else an imperceptible difference, in time, though the difference in weight is by no means negligible, with one body weighing twice as much as

8720-572: The particles of which a substance is composed; thermodynamics deals with the relationships between heat and other forms of energy. Electricity and magnetism have been studied as a single branch of physics since the intimate connection between them was discovered in the early 19th century; an electric current gives rise to a magnetic field , and a changing magnetic field induces an electric current. Electrostatics deals with electric charges at rest, electrodynamics with moving charges, and magnetostatics with magnetic poles at rest. Classical physics

8829-602: The positions of the planets . According to Asger Aaboe , the origins of Western astronomy can be found in Mesopotamia , and all Western efforts in the exact sciences are descended from late Babylonian astronomy . Egyptian astronomers left monuments showing knowledge of the constellations and the motions of the celestial bodies, while Greek poet Homer wrote of various celestial objects in his Iliad and Odyssey ; later Greek astronomers provided names, which are still used today, for most constellations visible from

8938-518: The possibility that the Sumerians originated from Dilmun, which was theorized to be the island of Bahrain in the Persian Gulf. In Sumerian mythology, Dilmun was also mentioned as the home of deities such as Enki . The status of Dilmun as the Sumerians’ ancestral homeland has not been established, but archaeologists have found evidence of civilization in Bahrain, namely the existence of Mesopotamian-style round disks. A prehistoric people who lived in

9047-469: The prehistoric Ubaid and Uruk periods. Sumerian written history reaches back to the 27th century BC and before, but the historical record remains obscure until the Early Dynastic III period, c.  23rd century BC , when the language of the written records becomes easier to decipher, which has allowed archaeologists to read contemporary records and inscriptions. The Akkadian Empire was

9156-524: The region before the Sumerians have been termed the " Proto-Euphrateans " or " Ubaidians ", and are theorized to have evolved from the Samarra culture of northern Mesopotamia. The Ubaidians, though never mentioned by the Sumerians themselves, are assumed by modern-day scholars to have been the first civilizing force in Sumer. They drained the marshes for agriculture , developed trade, and established industries, including weaving , leatherwork , metalwork , masonry , and pottery . Some scholars contest

9265-399: The related entities of energy and force . Physics is one of the most fundamental scientific disciplines. A scientist who specializes in the field of physics is called a physicist . Physics is one of the oldest academic disciplines . Over much of the past two millennia, physics, chemistry , biology , and certain branches of mathematics were a part of natural philosophy , but during

9374-433: The scribes. Gelb and Westenholz differentiate three stages of Old Akkadian: that of the pre-Sargonic era, that of the Akkadian empire, and that of the Ur III period that followed it. Akkadian and Sumerian coexisted as vernacular languages for about one thousand years, but by around 1800 BC, Sumerian was becoming more of a literary language familiar mainly only to scholars and scribes. Thorkild Jacobsen has argued that there

9483-665: The severed heads and other body parts of his enemies. His empire collapsed shortly after his death. Later, Lugal-zage-si , the priest-king of Umma, overthrew the primacy of the Lagash dynasty in the area, then conquered Uruk, making it his capital, and claimed an empire extending from the Persian Gulf to the Mediterranean. He was the last ethnically Sumerian king before Sargon of Akkad . The Akkadian Empire dates to c.  2234 –2154 BC ( middle chronology ), founded by Sargon of Akkad . The Eastern Semitic Akkadian language

9592-691: The south of Mesopotamia as the Babylonian Empire , just as the Old Assyrian Empire had already done in the north from the late 21st century BC. The Sumerian language continued as a sacerdotal language taught in schools in Babylonia and Assyria, much as Latin was used in the Medieval period, for as long as cuneiform was used. This period is generally taken to coincide with a major shift in population from southern Mesopotamia toward

9701-440: The speed being proportional to the weight and the speed of the object that is falling depends inversely on the density object it is falling through (e.g. density of air). He also stated that, when it comes to violent motion (motion of an object when a force is applied to it by a second object) that the speed that object moves, will only be as fast or strong as the measure of force applied to it. The problem of motion and its causes

9810-412: The speed of light. Planck, Schrödinger, and others introduced quantum mechanics, a probabilistic notion of particles and interactions that allowed an accurate description of atomic and subatomic scales. Later, quantum field theory unified quantum mechanics and special relativity. General relativity allowed for a dynamical, curved spacetime, with which highly massive systems and the large-scale structure of

9919-412: The study of probabilities and groups . Physics deals with a wide variety of systems, although certain theories are used by all physicists. Each of these theories was experimentally tested numerous times and found to be an adequate approximation of nature. For instance, the theory of classical mechanics accurately describes the motion of objects, provided they are much larger than atoms and moving at

10028-444: The top, air underneath fire, then water, then lastly earth. He also stated that when a small amount of one element enters the natural place of another, the less abundant element will automatically go towards its own natural place. For example, if there is a fire on the ground, the flames go up into the air in an attempt to go back into its natural place where it belongs. His laws of motion included: that heavier objects will fall faster,

10137-423: The understanding of electromagnetism , solid-state physics , and nuclear physics led directly to the development of technologies that have transformed modern society, such as television, computers, domestic appliances , and nuclear weapons ; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus . The word physics comes from

10246-423: The universe can be well-described. General relativity has not yet been unified with the other fundamental descriptions; several candidate theories of quantum gravity are being developed. Physics, as with the rest of science, relies on the philosophy of science and its " scientific method " to advance knowledge of the physical world. The scientific method employs a priori and a posteriori reasoning as well as

10355-573: The use of Bayesian inference to measure the validity of a given theory. Study of the philosophical issues surrounding physics, the philosophy of physics , involves issues such as the nature of space and time , determinism , and metaphysical outlooks such as empiricism , naturalism , and realism . Many physicists have written about the philosophical implications of their work, for instance Laplace , who championed causal determinism , and Erwin Schrödinger , who wrote on quantum mechanics. The mathematical physicist Roger Penrose has been called

10464-988: The validity of a theory in a logical, unbiased, and repeatable way. To that end, experiments are performed and observations are made in order to determine the validity or invalidity of a theory. A scientific law is a concise verbal or mathematical statement of a relation that expresses a fundamental principle of some theory, such as Newton's law of universal gravitation. Theorists seek to develop mathematical models that both agree with existing experiments and successfully predict future experimental results, while experimentalists devise and perform experiments to test theoretical predictions and explore new phenomena. Although theory and experiment are developed separately, they strongly affect and depend upon each other. Progress in physics frequently comes about when experimental results defy explanation by existing theories, prompting intense focus on applicable modelling, and when new theories generate experimentally testable predictions , which inspire

10573-499: The valleys of the Tigris and Euphrates rivers, Sumerian farmers grew an abundance of grain and other crops, a surplus which enabled them to form urban settlements. The world's earliest known texts come from the Sumerian cities of Uruk and Jemdet Nasr , and date to between c.  3350  – c.  2500 BC , following a period of proto-writing c.  4000  – c.  2500 BC . The term "Sumer" ( Akkadian : 𒋗𒈨𒊒 , romanized:  šumeru ) comes from

10682-579: The way vision works. Physics became a separate science when early modern Europeans used experimental and quantitative methods to discover what are now considered to be the laws of physics . Major developments in this period include the replacement of the geocentric model of the Solar System with the heliocentric Copernican model , the laws governing the motion of planetary bodies (determined by Kepler between 1609 and 1619), Galileo's pioneering work on telescopes and observational astronomy in

10791-399: The works of many scientists like Ibn Sahl , Al-Kindi , Ibn al-Haytham , Al-Farisi and Avicenna . The most notable work was The Book of Optics (also known as Kitāb al-Manāẓir), written by Ibn al-Haytham, in which he presented the alternative to the ancient Greek idea about vision. In his Treatise on Light as well as in his Kitāb al-Manāẓir , he presented a study of the phenomenon of

10900-550: Was a step toward the modern ideas of inertia and momentum. Islamic scholarship inherited Aristotelian physics from the Greeks and during the Islamic Golden Age developed it further, especially placing emphasis on observation and a priori reasoning, developing early forms of the scientific method . The most notable innovations under Islamic scholarship were in the field of optics and vision, which came from

11009-610: Was a temple for a goddess, or a female figure when headed by a male god) towards a more secular Lugal (Lu = man, Gal = great) and includes such legendary patriarchal figures as Dumuzid , Lugalbanda and Gilgamesh —who reigned shortly before the historic record opens c. 2900 BC, when the now deciphered syllabic writing started to develop from the early pictograms. The center of Sumerian culture remained in southern Mesopotamia, even though rulers soon began expanding into neighboring areas, and neighboring Semitic groups adopted much of Sumerian culture for their own. The earliest dynastic king on

11118-410: Was associated with increased war. Cities became walled, and increased in size as undefended villages in southern Mesopotamia disappeared. Both Enmerkar and Gilgamesh are credited with having built the walls of Uruk. The dynasty of Lagash (c. 2500–2270 BC), though omitted from the king list, is well attested through several important monuments and many archaeological finds. Although short-lived, one of

11227-479: Was derived from the Samarran culture from northern Mesopotamia. It is not known whether or not these were the actual Sumerians who are identified with the later Uruk culture. The story of the passing of the gifts of civilization ( me ) to Inanna , goddess of Uruk and of love and war, by Enki , god of wisdom and chief god of Eridu, may reflect the transition from Eridu to Uruk. The archaeological transition from

11336-532: Was first permanently settled between c.  5500  – c.  3300 BC by a West Asian people who spoke the Sumerian language (pointing to the names of cities, rivers, basic occupations, etc., as evidence), a non-Semitic and non- Indo-European agglutinative language isolate . Others have suggested that the Sumerians were a North African people who migrated from the Green Sahara into

11445-750: Was flooded at the end of the Ice Age . Sumerian civilization took form in the Uruk period (4th millennium BC), continuing into the Jemdet Nasr and Early Dynastic periods. The Sumerian city of Eridu , on the coast of the Persian Gulf, is considered to have been one of the oldest cities , where three separate cultures may have fused: that of peasant Ubaidian farmers, living in mud-brick huts and practicing irrigation; that of mobile nomadic Semitic pastoralists living in black tents and following herds of sheep and goats; and that of fisher folk, living in reed huts in

11554-513: Was found to be correct approximately 2000 years after it was proposed by Leucippus and his pupil Democritus . During the classical period in Greece (6th, 5th and 4th centuries BCE) and in Hellenistic times , natural philosophy developed along many lines of inquiry. Aristotle ( Greek : Ἀριστοτέλης , Aristotélēs ) (384–322 BCE), a student of Plato , wrote on many subjects, including

11663-417: Was not scrutinized until Philoponus appeared; unlike Aristotle, who based his physics on verbal argument, Philoponus relied on observation. On Aristotle's physics Philoponus wrote: But this is completely erroneous, and our view may be corroborated by actual observation more effectively than by any sort of verbal argument. For if you let fall from the same height two weights of which one is many times as heavy as

11772-548: Was studied carefully, leading to the philosophical notion of a " prime mover " as the ultimate source of all motion in the world (Book 8 of his treatise Physics ). The Western Roman Empire fell to invaders and internal decay in the fifth century, resulting in a decline in intellectual pursuits in western Europe. By contrast, the Eastern Roman Empire (usually known as the Byzantine Empire ) resisted

11881-483: Was the major language. Henceforth, Sumerian remained only a literary and liturgical language, similar to the position occupied by Latin in medieval Europe. Following an Elamite invasion and sack of Ur during the rule of Ibbi-Sin (c. 2028–2004 BC), Sumer came under Amorite rule (taken to introduce the Middle Bronze Age ). The independent Amorite states of the 20th to 18th centuries are summarized as

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