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126-427: Demolition (also known as razing , cartage , and wrecking ) is the science and engineering in safely and efficiently tearing down buildings and other artificial structures . Demolition contrasts with deconstruction , which involves taking a building apart while carefully preserving valuable elements for reuse purposes. For small buildings, such as houses , that are only two or three stories high, demolition

252-410: A fuel . Deposits of this substance can interfere with the airflow and more importantly, they are combustible and can cause dangerous chimney fires if the deposits ignite in the chimney. Heaters that burn natural gas drastically reduce the amount of creosote buildup due to natural gas burning much cleaner and more efficiently than traditional solid fuels. While in most cases there is no need to clean

378-409: A building fails to collapse completely the structure may be unstable, tilting at a dangerous angle, and filled with un-detonated but still primed explosives, making it difficult for workers to approach safely. A third danger comes from air overpressure that occurs during the implosion. If the sky is clear, the shock wave , a wave of energy and sound, travels upwards and disperses, but if cloud coverage

504-643: A building immediately after purchasing it, freeing up the land for a new, typically larger building. The term first entered the real estate lexicon in the 1990s. A teardown is often done when the redevelopment value of a plot of land exceeds the value of the existing building. In the 2000s, teardowns by wealthy baby boomers replacing houses across America with outsized McMansions became so common that municipal building codes in many areas were revised, putting up more barriers to tearing down an existing homes. Teardowns are often cheaper than restoring an existing, dilapidated building, but can diminish historical value due to

630-427: A building. Some materials must be removed, such as glass that can form deadly projectiles, and insulation that can scatter over a wide area. Non-load bearing partitions and drywall are removed. Selected columns on floors where explosives will be set are drilled and high explosives such as nitroglycerin , TNT , RDX , or C4 are placed in the holes. Smaller columns and walls are wrapped in detonating cord . The goal

756-613: A cap and be insulated if they service solid fuel appliances, but following the manufacturer's instructions carefully. Aluminum and galvanized steel chimneys are known as class A and class B chimneys. Class A are either an insulated, double wall stainless steel pipe or triple wall, air-insulated pipe often known by its genericized trade name Metalbestos. Class B are uninsulated double wall pipes often called B-vent, and are only used to vent non-condensing gas appliances. These may have an aluminum inside layer and galvanized steel outside layer. Concrete flue liners are like clay liners but are made of

882-538: A century before, were first observed . In 2019, the international collaboration Event Horizon Telescope presented the first direct image of a black hole 's accretion disc . Modern science is commonly divided into three major branches : natural science , social science , and formal science . Each of these branches comprises various specialised yet overlapping scientific disciplines that often possess their own nomenclature and expertise. Both natural and social sciences are empirical sciences , as their knowledge

1008-580: A concrete windshield with a number of flues on the inside. The 300 m (980 ft) high steam plant chimney at the Secunda CTL 's synthetic fuel plant in Secunda, South Africa consists of a 26 m (85 ft) diameter windshield with four 4.6 metre diameter concrete flues which are lined with refractory bricks built on rings of corbels spaced at 10 metre intervals. The reinforced concrete can be cast by conventional formwork or sliding formwork. The height

1134-474: A discipline. Ideas on human nature, society, and economics evolved during the Enlightenment. Hume and other Scottish Enlightenment thinkers developed A Treatise of Human Nature , which was expressed historically in works by authors including James Burnett , Adam Ferguson , John Millar and William Robertson , all of whom merged a scientific study of how humans behaved in ancient and primitive cultures with

1260-399: A downdraft of smoke and wind down the chimney. An H-style cap is a chimney top constructed from chimney pipes shaped like the letter H. It is an age-old method of regulating draft in situations where prevailing winds or turbulences cause downdraft and back-puffing. Although the H cap has a distinct advantage over most other downdraft caps, it fell out of favor because of its bulky design. It

1386-411: A few of their scientific predecessors – Galileo , Kepler , Boyle , and Newton principally – as the guides to every physical and social field of the day. The 18th century saw significant advancements in the practice of medicine and physics; the development of biological taxonomy by Carl Linnaeus ; a new understanding of magnetism and electricity; and the maturation of chemistry as

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1512-655: A flue liner. Chimneys built without a liner can usually have a liner added, but the type of liner needs to match the type of appliance it services. Flue liners may be clay or concrete tile, metal, or poured in place concrete. Clay tile flue liners are very common in the United States, although it is the only liner that does not meet Underwriters Laboratories 1777 approval and frequently they have problems such as cracked tiles and improper installation. Clay tiles are usually about 2 feet (0.61 m) long, available in various sizes and shapes, and are installed in new construction as

1638-663: A gas chimney on an annual basis that does not mean that other parts of the chimney cannot fall into disrepair. Disconnected or loose chimney fittings caused by corrosion over time can pose serious dangers for residents due to leakage of carbon monoxide into the home. Thus, it is recommended—and in some countries even mandatory—that chimneys be inspected annually and cleaned on a regular basis to prevent these problems. The workers who perform this task are called chimney sweeps or steeplejacks . This work used to be done largely by child labour and, as such , features in Victorian literature . In

1764-423: A greater role in knowledge creation and it was not until the 19th century that many of the institutional and professional features of science began to take shape, along with the changing of "natural philosophy" to "natural science". New knowledge in science is advanced by research from scientists who are motivated by curiosity about the world and a desire to solve problems. Contemporary scientific research

1890-466: A highly stable universe where there could be little loss of resources. However, with the advent of the steam engine and the Industrial Revolution there was an increased understanding that not all forms of energy have the same energy qualities , the ease of conversion to useful work or to another form of energy. This realisation led to the development of the laws of thermodynamics , in which

2016-455: A hypothesis proves unsatisfactory it is modified or discarded. If the hypothesis survives testing, it may become adopted into the framework of a scientific theory , a validly reasoned , self-consistent model or framework for describing the behaviour of certain natural events. A theory typically describes the behaviour of much broader sets of observations than a hypothesis; commonly, a large number of hypotheses can be logically bound together by

2142-433: A manageable size, and to remove reinforcing steel. For tall concrete buildings, where neither explosive nor high reach demolition with an excavator is safe or practical, the "inside-out" method is used, whereby remotely operated mini-excavators demolish the building from the inside, whilst maintaining the outer walls of the building as a scaffolding, as each floor is demolished. To control dust, fire hoses are used to maintain

2268-430: A metal flue. Bracing or strapping old masonry chimneys has not proven to be very effective in preventing damage or injury from earthquakes. It is now possible to buy "faux-brick" facades to cover these modern chimney structures. Other potential problems include: Several chimneys with observation decks were built. The following possibly incomplete list shows them. At several thermal power stations at least one smokestack

2394-407: A new non- teleological way. This implied a shift in the view of objects: objects were now considered as having no innate goals. Leibniz assumed that different types of things all work according to the same general laws of nature, with no special formal or final causes. During this time the declared purpose and value of science became producing wealth and inventions that would improve human lives, in

2520-507: A noncombustible wall thimble allows a vent pipe to run directly through the external wall. On a pitched roof where a chimney penetrates a roof, flashing is used to seal up the joints. The down-slope piece is called an apron, the sides receive step flashing and a cricket is used to divert water around the upper side of the chimney underneath the flashing. Industrial chimneys are commonly referred to as flue-gas stacks and are generally external structures, as opposed to those built into

2646-458: A preference for one outcome over another. Eliminating the bias can be achieved through transparency, careful experimental design , and a thorough peer review process of the experimental results and conclusions. After the results of an experiment are announced or published, it is normal practice for independent researchers to double-check how the research was performed, and to follow up by performing similar experiments to determine how dependable

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2772-456: A priori disciplines and because of this, there is disagreement on whether they constitute a science. Nevertheless, the formal sciences play an important role in the empirical sciences. Calculus , for example, was initially invented to understand motion in physics. Natural and social sciences that rely heavily on mathematical applications include mathematical physics , chemistry , biology , finance , and economics . Applied science

2898-413: A refractory cement and are more durable than the clay liners. Poured in place concrete liners are made by pouring special concrete into the existing chimney with a form. These liners are highly durable, work with any heating appliance, and can reinforce a weak chimney, but they are irreversible. A chimney pot is placed on top of the chimney to expand the length of the chimney inexpensively, and to improve

3024-400: A revolution in information technology and the rise of the global internet and mobile computing , including smartphones . The need for mass systematisation of long, intertwined causal chains and large amounts of data led to the rise of the fields of systems theory and computer-assisted scientific modelling . The Human Genome Project was completed in 2003 by identifying and mapping all of

3150-457: A separate discipline from philosophy when Wilhelm Wundt founded the first laboratory for psychological research in 1879. During the mid-19th century Charles Darwin and Alfred Russel Wallace independently proposed the theory of evolution by natural selection in 1858, which explained how different plants and animals originated and evolved. Their theory was set out in detail in Darwin's book On

3276-592: A separate field because they rely on deductive reasoning instead of the scientific method or empirical evidence as their main methodology. Applied sciences are disciplines that use scientific knowledge for practical purposes, such as engineering and medicine . The history of science spans the majority of the historical record, with the earliest written records of identifiable predecessors to modern science dating to Bronze Age Egypt and Mesopotamia from around 3000 to 1200 BCE . Their contributions to mathematics, astronomy , and medicine entered and shaped

3402-475: A set of basic assumptions that are needed to justify the scientific method: there is an objective reality shared by all rational observers; this objective reality is governed by natural laws ; these laws were discovered by means of systematic observation and experimentation. Mathematics is essential in the formation of hypotheses , theories , and laws, because it is used extensively in quantitative modelling, observing, and collecting measurements . Statistics

3528-463: A set of rules. It includes mathematics, systems theory , and theoretical computer science . The formal sciences share similarities with the other two branches by relying on objective, careful, and systematic study of an area of knowledge. They are, however, different from the empirical sciences as they rely exclusively on deductive reasoning, without the need for empirical evidence, to verify their abstract concepts. The formal sciences are therefore

3654-412: A short vertical chimney in a remote location where the fumes would cause less harm. Lead and silver deposits formed on the inside of these long chimneys, and periodically workers would be sent along the chimneys to scrape off these valuable deposits. As a result of the limited ability to handle transverse loads with brick, chimneys in houses were often built in a "stack", with a fireplace on each floor of

3780-478: A single theory. Thus, a theory is a hypothesis explaining various other hypotheses. In that vein, theories are formulated according to most of the same scientific principles as hypotheses. Scientists may generate a model , an attempt to describe or depict an observation in terms of a logical, physical or mathematical representation, and to generate new hypotheses that can be tested by experimentation. While performing experiments to test hypotheses, scientists may have

3906-429: A strong awareness of the determining forces of modernity . Modern sociology largely originated from this movement. In 1776, Adam Smith published The Wealth of Nations , which is often considered the first work on modern economics. During the nineteenth century many distinguishing characteristics of contemporary modern science began to take shape. These included the transformation of the life and physical sciences;

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4032-438: A unified theory in the early 20th-century when the modern synthesis reconciled Darwinian evolution with classical genetics . Albert Einstein 's theory of relativity and the development of quantum mechanics complement classical mechanics to describe physics in extreme length , time and gravity . Widespread use of integrated circuits in the last quarter of the 20th century combined with communications satellites led to

4158-563: A water tank on their structure. This combination has the advantage that the warm smoke running through the chimney prevents the water in the tank from freezing. Before World War II such structures were not uncommon, especially in countries influenced by Germany. Chimneys can carry antennas for radio relay services, cell phone transmissions, FM-radio and TV on their structure. Also long wire antennas for mediumwave transmissions can be fixed at chimneys. In all cases it had to be considered that these objects can easily corrode especially when placed near

4284-422: A wet demolition. Hoses may be held by workers, secured in fixed location, or attached to lifts to gain elevation. Loaders or bulldozers may also be used to demolish a building. They are typically equipped with "rakes" (thick pieces of steel that could be an I-beam or tube) that are used to ram building walls. Skid loaders and loaders will also be used to take materials out and sort steel. The technique of Vérinage

4410-682: Is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into two or three major branches: the natural sciences (e.g., physics , chemistry , and biology ), which study the physical world ; and the behavioural sciences (e.g., economics , psychology , and sociology ), which study individuals and societies. The formal sciences (e.g., logic , mathematics, and theoretical computer science ), which study formal systems governed by axioms and rules, are sometimes described as being sciences as well; however, they are often regarded as

4536-630: Is a rather simple process. The building is pulled down either manually or mechanically using large hydraulic equipment: elevated work platforms, cranes, excavators or bulldozers . Larger buildings may require the use of a wrecking ball , a heavy weight on a cable that is swung by a crane into the side of the buildings. Wrecking balls are especially effective against masonry, but are less easily controlled and often less efficient than other methods. Newer methods may use rotational hydraulic shears and silenced rockbreakers attached to excavators to cut or break through wood, steel, and concrete. The use of shears

4662-487: Is based on empirical observations and is capable of being tested for its validity by other researchers working under the same conditions. Natural science is the study of the physical world. It can be divided into two main branches: life science and physical science . These two branches may be further divided into more specialised disciplines. For example, physical science can be subdivided into physics, chemistry , astronomy , and earth science . Modern natural science

4788-439: Is becoming a central feature of computational contributions to science, for example in agent-based computational economics , random forests , topic modeling and various forms of prediction. However, machines alone rarely advance knowledge as they require human guidance and capacity to reason; and they can introduce bias against certain social groups or sometimes underperform against humans. Interdisciplinary science involves

4914-433: Is called "natural draught/draft", "natural ventilation" , "chimney effect", or " stack effect ". The taller the stack, the more draught or draft is created. There can be cases of diminishing returns: if a stack is overly tall in relation to the heat being sent out of the stack, the flue gases may cool before reaching the top of the chimney. This condition can result in poor drafting, and in the case of wood burning appliances,

5040-439: Is combusted in a stove, oven, fireplace, hot water boiler, or industrial furnace, the hot combustion product gases that are formed are called flue gases. Those gases are generally exhausted to the ambient outside air through chimneys or industrial flue-gas stacks (sometimes referred to as smokestacks). The combustion flue gases inside the chimneys or stacks are much hotter than the ambient outside air and therefore less dense than

5166-415: Is common for the metal to become warped over time, thus further degrading the ability of the throat damper to seal. However, the advantage of a throat damper is that it seals off the living space from the air mass in the chimney, which, especially for chimneys positioned on an outside of wall of the home, is generally very cold. It is possible in practice to use both a top damper and a throat damper to obtain

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5292-698: Is considered to be one of the most important publications in medicine and was used until the 18th century. By the eleventh century most of Europe had become Christian, and in 1088, the University of Bologna emerged as the first university in Europe. As such, demand for Latin translation of ancient and scientific texts grew, a major contributor to the Renaissance of the 12th century . Renaissance scholasticism in western Europe flourished, with experiments done by observing, describing, and classifying subjects in nature. In

5418-610: Is especially common when flame cutting would be dangerous. The tallest planned demolition of a building was the 52-storey 270 Park Avenue in New York City , which was built in 1960 and torn down in 2019–2021 to be replaced by 270 Park Avenue . Before any demolition activities can take place, there are many steps that must be carried out beforehand, including performing asbestos abatement , removing hazardous or regulated materials, obtaining necessary permits, submitting necessary notifications, disconnecting utilities, rodent baiting and

5544-512: Is found mostly in marine use but has been regaining popularity due to its energy-saving functionality. The H-cap stabilizes the draft rather than increasing it. Other downdraft caps are based on the Venturi effect , solving downdraft problems by increasing the updraft constantly resulting in much higher fuel consumption. A chimney damper is a metal plate that can be positioned to close off the chimney when not in use and prevent outside air from entering

5670-535: Is highly collaborative and is usually done by teams in academic and research institutions , government agencies, and companies. The practical impact of their work has led to the emergence of science policies that seek to influence the scientific enterprise by prioritising the ethical and moral development of commercial products, armaments, health care, public infrastructure, and environmental protection . The word science has been used in Middle English since

5796-417: Is low, the shock wave can travel outwards, breaking windows or causing other damage to surrounding buildings. Controlled implosion, being spectacular, is the method that the general public often thinks of when discussing demolition; however, it can be dangerous and is only used as a last resort when other methods are impractical or too costly. The destruction of large buildings has become increasingly common as

5922-515: Is lowered and this process is repeated for each floor. This technique is safer and more environmentally friendly, and is useful in areas of high population density . To demolish bridges, hoe rams are typically used to remove the concrete road deck and piers, while hydraulic shears are used to remove the bridge's structural steel . Fred Dibnah used a manual method of demolition to remove industrial chimneys in Great Britain. He cut an ingress at

6048-419: Is the minimum required flow area from water heater tank and A f =19.6 inch is the minimum flow area from a furnace of a central heating system. Gas fired appliances must have a draft hood to cool combustion products entering the chimney and prevent updrafts or downdrafts. A characteristic problem of chimneys is they develop deposits of creosote on the walls of the structure when used with wood as

6174-447: Is the search for solutions to practical problems using this knowledge. Most understanding comes from basic research, though sometimes applied research targets specific practical problems. This leads to technological advances that were not previously imaginable. Scientific research involves using the scientific method , which seeks to objectively explain the events of nature in a reproducible way. Scientists usually take for granted

6300-526: Is the successor to the natural philosophy that began in Ancient Greece . Galileo , Descartes , Bacon , and Newton debated the benefits of using approaches that were more mathematical and more experimental in a methodical way. Still, philosophical perspectives, conjectures , and presuppositions , often overlooked, remain necessary in natural science. Systematic data collection, including discovery science , succeeded natural history , which emerged in

6426-427: Is the use of the scientific method and knowledge to attain practical goals and includes a broad range of disciplines such as engineering and medicine. Engineering is the use of scientific principles to invent, design and build machines, structures and technologies. Science may contribute to the development of new technologies. Medicine is the practice of caring for patients by maintaining and restoring health through

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6552-400: Is to ensure the pollutants are dispersed over a wider area to meet legal or other safety requirements. A flue liner is a secondary barrier in a chimney that protects the masonry from the acidic products of combustion, helps prevent flue gas from entering the house, and reduces the size of an oversized flue. Since the 1950s, building codes in many locations require newly built chimneys to have

6678-410: Is to use as little explosive as possible so that the structure will fail in a progressive collapse , and therefore only a few floors are rigged with explosives, so that it is safer due to fewer explosives, and costs less. The areas with explosives are covered in thick geotextile fabric and fencing to absorb flying debris. Far more time-consuming than the demolition itself is the clean-up of the site, as

6804-643: Is used as electricity pylon. The following possibly incomplete list shows them. Nearly all this structures exist in an area, which was once part of the Soviet Union. Although this use has the disadvantage that conductor ropes may corrode faster due to the exhaust gases, one can find such structures also sometimes in countries not influenced by the former Soviet Union. An example herefore is one chimney of Scholven Power Plant in Gelsenkirchen, which carries one circuit of an outgoing 220 kV-line. Chimneys can also carry

6930-465: Is used in France to weaken and buckle the supports of central floors promoting the collapse of the top part of a building onto the bottom resulting in a rapid, symmetrical, collapse. The Japanese company Kajima Construction has developed a new method of demolishing buildings which involves using computer-controlled hydraulic jacks to support the bottom floor as the supporting columns are removed. The floor

7056-403: Is used to make falsifiable predictions, which are typically posted before being tested by experimentation. Disproof of a prediction is evidence of progress. Experimentation is especially important in science to help establish causal relationships to avoid the correlation fallacy , though in some sciences such as astronomy or geology, a predicted observation might be more appropriate. When

7182-410: Is used to summarise and analyse data, which allows scientists to assess the reliability of experimental results. In the scientific method an explanatory thought experiment or hypothesis is put forward as an explanation using parsimony principles and is expected to seek consilience  – fitting with other accepted facts related to an observation or scientific question. This tentative explanation

7308-610: The Byzantine empire and Arabic translations were done by groups such as the Nestorians and the Monophysites . Under the Caliphate , these Arabic translations were later improved and developed by Arabic scientists. By the 6th and 7th centuries, the neighbouring Sassanid Empire established the medical Academy of Gondeshapur , which is considered by Greek, Syriac, and Persian physicians as

7434-464: The CO 2 emissions of the removing of a building in comparison to demolition. The development of plant and equipment has allowed for the easier segregation of demolition waste types on site and the reuse within the construction of the replacement building. On site crushers allow the demolished concrete to be reused as type 1 crushed aggregate either as a piling mat for ground stabilization or as aggregate in

7560-706: The Early Middle Ages (400 to 1000 CE), but in the Medieval renaissances ( Carolingian Renaissance , Ottonian Renaissance and the Renaissance of the 12th century ) scholarship flourished again. Some Greek manuscripts lost in Western Europe were preserved and expanded upon in the Middle East during the Islamic Golden Age , along with the later efforts of Byzantine Greek scholars who brought Greek manuscripts from

7686-484: The Middle Ages in some parts of Europe, a stepped gable design was developed, partly to provide access to chimneys without use of ladders. Masonry (brick) chimneys have also proven to be particularly prone to crumbling during earthquakes . Government housing authorities in cities prone to earthquakes such as San Francisco , Los Angeles , and San Diego now recommend building new homes with stud-framed chimneys around

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7812-599: The Proto-Italic language as * skije- or * skijo- meaning "to know", which may originate from Proto-Indo-European language as *skh 1 -ie , *skh 1 -io , meaning "to incise". The Lexikon der indogermanischen Verben proposed sciō is a back-formation of nescīre , meaning "to not know, be unfamiliar with", which may derive from Proto-Indo-European *sekH- in Latin secāre , or *skh 2 - , from *sḱʰeh2(i)- meaning "to cut". In

7938-555: The camera obscura and the telescope . At the start of the Renaissance, Roger Bacon , Vitello , and John Peckham each built up a scholastic ontology upon a causal chain beginning with sensation, perception, and finally apperception of the individual and universal forms of Aristotle. A model of vision later known as perspectivism was exploited and studied by the artists of the Renaissance. This theory uses only three of Aristotle's four causes: formal, material, and final. In

8064-424: The historical method , case studies , and cross-cultural studies . Moreover, if quantitative information is available, social scientists may rely on statistical approaches to better understand social relationships and processes. Formal science is an area of study that generates knowledge using formal systems . A formal system is an abstract structure used for inferring theorems from axioms according to

8190-431: The materialistic sense of having more food, clothing, and other things. In Bacon's words , "the real and legitimate goal of sciences is the endowment of human life with new inventions and riches ", and he discouraged scientists from pursuing intangible philosophical or spiritual ideas, which he believed contributed little to human happiness beyond "the fume of subtle, sublime or pleasing [speculation]". Science during

8316-499: The prevention , diagnosis , and treatment of injury or disease. The applied sciences are often contrasted with the basic sciences , which are focused on advancing scientific theories and laws that explain and predict events in the natural world. Computational science applies computing power to simulate real-world situations, enabling a better understanding of scientific problems than formal mathematics alone can achieve. The use of machine learning and artificial intelligence

8442-481: The theory of impetus . His criticism served as an inspiration to medieval scholars and Galileo Galilei, who extensively cited his works ten centuries later. During late antiquity and the early Middle Ages , natural phenomena were mainly examined via the Aristotelian approach. The approach includes Aristotle's four causes : material, formal, moving, and final cause. Many Greek classical texts were preserved by

8568-488: The 12th century. The earliest surviving example of an English chimney is at the keep of Conisbrough Castle in Yorkshire , which dates from 1185 AD, but they did not become common in houses until the 16th and 17th centuries. Smoke hoods were an early method of collecting the smoke into a chimney. These were typically much wider than modern chimneys and started relatively high above the fire, meaning more heat could escape into

8694-406: The 13th century, medical teachers and students at Bologna began opening human bodies, leading to the first anatomy textbook based on human dissection by Mondino de Luzzi . New developments in optics played a role in the inception of the Renaissance , both by challenging long-held metaphysical ideas on perception, as well as by contributing to the improvement and development of technology such as

8820-707: The 14th century in the sense of "the state of knowing". The word was borrowed from the Anglo-Norman language as the suffix -cience , which was borrowed from the Latin word scientia , meaning "knowledge, awareness, understanding". It is a noun derivative of the Latin sciens meaning "knowing", and undisputedly derived from the Latin sciō , the present participle scīre , meaning "to know". There are many hypotheses for science ' s ultimate word origin. According to Michiel de Vaan , Dutch linguist and Indo-Europeanist , sciō may have its origin in

8946-444: The 16th century by describing and classifying plants, animals, minerals, and other biotic beings. Today, "natural history" suggests observational descriptions aimed at popular audiences. Social science is the study of human behaviour and the functioning of societies. It has many disciplines that include, but are not limited to anthropology , economics, history, human geography , political science , psychology, and sociology. In

9072-633: The 3rd millennium BCE, the ancient Egyptians developed a decimal numbering system , solved practical problems using geometry , and developed a calendar . Their healing therapies involved drug treatments and the supernatural, such as prayers, incantations , and rituals. The ancient Mesopotamians used knowledge about the properties of various natural chemicals for manufacturing pottery , faience , glass, soap, metals, lime plaster , and waterproofing. They studied animal physiology , anatomy , behaviour , and astrology for divinatory purposes. The Mesopotamians had an intense interest in medicine and

9198-404: The Enlightenment was dominated by scientific societies and academies , which had largely replaced universities as centres of scientific research and development. Societies and academies were the backbones of the maturation of the scientific profession. Another important development was the popularisation of science among an increasingly literate population. Enlightenment philosophers turned to

9324-634: The Greek natural philosophy of classical antiquity , whereby formal attempts were made to provide explanations of events in the physical world based on natural causes, while further advancements, including the introduction of the Hindu–Arabic numeral system , were made during the Golden Age of India . Scientific research deteriorated in these regions after the fall of the Western Roman Empire during

9450-410: The Greek philosopher Leucippus and his student Democritus . Later, Epicurus would develop a full natural cosmology based on atomism, and would adopt a "canon" (ruler, standard) which established physical criteria or standards of scientific truth. The Greek doctor Hippocrates established the tradition of systematic medical science and is known as " The Father of Medicine ". A turning point in

9576-453: The Milesian school, which was founded by Thales of Miletus and later continued by his successors Anaximander and Anaximenes , were the first to attempt to explain natural phenomena without relying on the supernatural . The Pythagoreans developed a complex number philosophy and contributed significantly to the development of mathematical science. The theory of atoms was developed by

9702-551: The Origin of Species , published in 1859. Separately, Gregor Mendel presented his paper, " Experiments on Plant Hybridization " in 1865, which outlined the principles of biological inheritance, serving as the basis for modern genetics. Early in the 19th century John Dalton suggested the modern atomic theory , based on Democritus's original idea of indivisible particles called atoms . The laws of conservation of energy , conservation of momentum and conservation of mass suggested

9828-472: The advent of writing systems in early civilisations like Ancient Egypt and Mesopotamia , creating the earliest written records in the history of science in around 3000 to 1200 BCE . Although the words and concepts of "science" and "nature" were not part of the conceptual landscape at the time, the ancient Egyptians and Mesopotamians made contributions that would later find a place in Greek and medieval science: mathematics, astronomy, and medicine. From

9954-413: The ambient air. That causes the bottom of the vertical column of hot flue gas to have a lower pressure than the pressure at the bottom of a corresponding column of outside air. That higher pressure outside the chimney is the driving force that moves the required combustion air into the combustion zone and also moves the flue gas up and out of the chimney. That movement or flow of combustion air and flue gas

10080-447: The base of the chimney—supporting the brickwork with wooden props—and then burning away the props so that the chimney fell, using no explosives and usually hand-operated power tools. Large buildings, tall chimneys , smokestacks , bridges, and increasingly some smaller structures may be destroyed by building implosion using explosives . Imploding a structure is very fast—the collapse itself only takes seconds—and an expert can ensure that

10206-564: The benefits of both. The two top damper designs currently on the market are the Lyemance (pivoting door) and the Lock Top (translating door). In the late Middle Ages in Western Europe the design of stepped gables arose to allow maintenance access to the chimney top, especially for tall structures such as castles and great manor houses . When coal, oil, natural gas, wood, or any other fuel

10332-429: The bricks around tile liners. To control downdrafts, venting caps (often called chimney pots ) with a variety of designs are sometimes placed on the top of chimneys. In the 18th and 19th centuries, the methods used to extract lead from its ore produced large amounts of toxic fumes. In the north of England, long near-horizontal chimneys were built, often more than 3 km (2 mi) long, which typically terminated in

10458-403: The chimney and making it onto the roof. Although the masonry inside the chimney can absorb a large amount of moisture which later evaporates, rainwater can collect at the base of the chimney. Sometimes weep holes are placed at the bottom of the chimney to drain out collected water. A chimney cowl or wind directional cap is a helmet-shaped chimney cap that rotates to align with the wind and prevent

10584-459: The chimney is built. A refractory cement is used between each tile. Metal liners may be stainless steel, aluminum, or galvanized iron and may be flexible or rigid pipes. Stainless steel is made in several types and thicknesses. Type 304 is used with firewood , wood pellet fuel , and non-condensing oil appliances, types 316 and 321 with coal, and type AL 29-4C is used with high efficiency condensing gas appliances. Stainless steel liners must have

10710-430: The chimney's draft . A chimney with more than one pot on it indicates that multiple fireplaces on different floors share the chimney. A cowl is placed on top of the chimney to prevent birds and other animals from nesting in the chimney. They often feature a rain guard to prevent rain or snow from going down the chimney. A metal wire mesh is often used as a spark arrestor to minimize burning debris from rising out of

10836-398: The combination of two or more disciplines into one, such as bioinformatics , a combination of biology and computer science or cognitive sciences . The concept has existed since the ancient Greek period and it became popular again in the 20th century. Scientific research can be labelled as either basic or applied research. Basic research is the search for knowledge and applied research

10962-435: The cooling of the gases before emission can cause creosote to condense near the top of the chimney. The creosote can restrict the exit of flue gases and may pose a fire hazard. Designing chimneys and stacks to provide the correct amount of natural draft involves a number of design factors, many of which require iterative trial-and-error methods. As a "first guess" approximation, the following equation can be used to estimate

11088-610: The course of tens of thousands of years, taking different forms around the world, and few details are known about the very earliest developments. Women likely played a central role in prehistoric science, as did religious rituals . Some scholars use the term " protoscience " to label activities in the past that resemble modern science in some but not all features; however, this label has also been criticised as denigrating, or too suggestive of presentism , thinking about those activities only in relation to modern categories. Direct evidence for scientific processes becomes clearer with

11214-491: The debris is loaded into trucks and hauled away. An alternative approach to demolition is the deconstruction of a building with the goal of minimizing the amount of materials going to landfills . This "green" approach is applied by removing the materials by type material and segregating them for reuse or recycling . With proper planning this approach has resulted in landfill diversion rates that exceed 90% of an entire building and its contents in some cases. It also vastly reduces

11340-404: The development of site-specific safety and work plans. The typical razing of a building is accomplished as follows: In some cases a crane with a wrecking ball is used to demolish the structure down to a certain manageable height. At that point undermining takes place as described above. However, crane mounted demolition balls are rarely used within demolition due to the uncontrollable nature of

11466-505: The discovery of radioactivity by Henri Becquerel and Marie Curie in 1896, Marie Curie then became the first person to win two Nobel Prizes . In the next year came the discovery of the first subatomic particle, the electron . In the first half of the century the development of antibiotics and artificial fertilisers improved human living standards globally. Harmful environmental issues such as ozone depletion , ocean acidification , eutrophication , and climate change came to

11592-483: The dispersion of pollutants at higher altitudes can reduce their impact on the immediate surroundings. The dispersion of pollutants over a greater area can reduce their concentrations and facilitate compliance with regulatory limits. Industrial chimney use dates to the Romans , who drew smoke from their bakeries with tubes embedded in the walls. However, domestic chimneys first appeared in large dwellings in northern Europe in

11718-517: The dying Byzantine Empire to Western Europe at the start of the Renaissance . The recovery and assimilation of Greek works and Islamic inquiries into Western Europe from the 10th to 13th century revived " natural philosophy ", which was later transformed by the Scientific Revolution that began in the 16th century as new ideas and discoveries departed from previous Greek conceptions and traditions. The scientific method soon played

11844-584: The earliest medical prescriptions appeared in Sumerian during the Third Dynasty of Ur . They seem to have studied scientific subjects which had practical or religious applications and had little interest in satisfying curiosity. In classical antiquity , there is no real ancient analogue of a modern scientist. Instead, well-educated, usually upper-class, and almost universally male individuals performed various investigations into nature whenever they could afford

11970-437: The environmental impacts of burning fossil fuels by industrial society, including the electric industry during its earliest history. The term smokestack (colloquially, stack ) is also used when referring to locomotive chimneys or ship chimneys , and the term funnel can also be used. The height of a chimney influences its ability to transfer flue gases to the external environment via stack effect . Additionally,

12096-421: The exhaust. Sometimes chimneys were converted into radio towers and are not useable as ventilation structure any more. As chimneys are often the tallest part of a factory, they offer the possibility as advertising billboard either by writing the name of the company to which they belong on the shaft or by installing advertisement boards on their structure. At some power stations, which are equipped with plants for

12222-407: The fireplace from the chimney. The advantage of a top damper is the tight weatherproof seal that it provides when closed, which prevents cold outside air from flowing down the chimney and into the living space—a feature that can rarely be matched by the metal-on-metal seal afforded by a throat damper. Additionally, because the throat damper is subjected to intense heat from the fire directly below, it

12348-462: The free energy of the universe is seen as constantly declining: the entropy of a closed universe increases over time. The electromagnetic theory was established in the 19th century by the works of Hans Christian Ørsted , André-Marie Ampère , Michael Faraday , James Clerk Maxwell , Oliver Heaviside , and Heinrich Hertz . The new theory raised questions that could not easily be answered using Newton's framework. The discovery of X-rays inspired

12474-425: The frequent use of precision instruments; the emergence of terms such as "biologist", "physicist", and "scientist"; an increased professionalisation of those studying nature; scientists gaining cultural authority over many dimensions of society; the industrialisation of numerous countries; the thriving of popular science writings; and the emergence of science journals. During the late 19th century, psychology emerged as

12600-519: The genes of the human genome . The first induced pluripotent human stem cells were made in 2006, allowing adult cells to be transformed into stem cells and turn into any cell type found in the body. With the affirmation of the Higgs boson discovery in 2013, the last particle predicted by the Standard Model of particle physics was found. In 2015, gravitational waves , predicted by general relativity

12726-431: The heliocentric model. The printing press was widely used to publish scholarly arguments, including some that disagreed widely with contemporary ideas of nature. Francis Bacon and René Descartes published philosophical arguments in favour of a new type of non-Aristotelian science. Bacon emphasised the importance of experiment over contemplation, questioned the Aristotelian concepts of formal and final cause, promoted

12852-562: The history of early philosophical science was Socrates ' example of applying philosophy to the study of human matters, including human nature, the nature of political communities, and human knowledge itself. The Socratic method as documented by Plato 's dialogues is a dialectic method of hypothesis elimination: better hypotheses are found by steadily identifying and eliminating those that lead to contradictions. The Socratic method searches for general commonly-held truths that shape beliefs and scrutinises them for consistency. Socrates criticised

12978-439: The house sharing a single chimney, often with such a stack at the front and back of the house. Today's central heating systems have made chimney placement less critical, and the use of non-structural gas vent pipe allows a flue gas conduit to be installed around obstructions and through walls. Most modern high-efficiency heating appliances do not require a chimney. Such appliances are generally installed near an external wall, and

13104-554: The idea that science should study the laws of nature and the improvement of all human life. Descartes emphasised individual thought and argued that mathematics rather than geometry should be used to study nature. At the start of the Age of Enlightenment , Isaac Newton formed the foundation of classical mechanics by his Philosophiæ Naturalis Principia Mathematica , greatly influencing future physicists. Gottfried Wilhelm Leibniz incorporated terms from Aristotelian physics , now used in

13230-426: The interior space, and can be opened to permit hot gases to exhaust when a fire is burning. A top damper or cap damper is a metal spring door placed at the top of the chimney with a long metal chain that allows one to open and close the damper from the fireplace. A throat damper is a metal plate at the base of the chimney, just above the firebox, that can be opened and closed by a lever, gear, or chain to seal off

13356-509: The late 20th century active recruitment of women and elimination of sex discrimination greatly increased the number of women scientists, but large gender disparities remained in some fields. The discovery of the cosmic microwave background in 1964 led to a rejection of the steady-state model of the universe in favour of the Big Bang theory of Georges Lemaître . The century saw fundamental changes within science disciplines. Evolution became

13482-423: The massive housing projects of the 1960s and 1970s are being leveled around the world. At 439 feet (134 m) and 2,200,000 square feet (200,000 m), the J. L. Hudson Department Store and Addition is the tallest steel framed building and largest single structure ever imploded . It takes several weeks or months to prepare a building for implosion. All items of value, such as copper wiring, are stripped from

13608-415: The mixing of concrete. Timber waste can be shredded using specialist timber shredders and composted, or used to form manufactured timber boards, such as MDF or chipboard . Safety is paramount; a site safety officer is usually assigned to each project to enforce all safety rules and regulations. In real estate, a teardown or knockdown - also derisively called "bash and build" - is a term for demolishing

13734-491: The more generic, cookie-cutter appearance of new houses and buildings compared to antique ones. Sometimes, saving the older building can still be viable if the owner spends more money to restore it. Purposely ignoring issues with a building in order to force demolition for public safety reasons is known as "demolition by neglect". "Canyon effect" is a term used to describe when smaller houses are surrounded by new, multi-story buildings with blank walls. Science Science

13860-608: The most important medical center of the ancient world. The House of Wisdom was established in Abbasid -era Baghdad , Iraq , where the Islamic study of Aristotelianism flourished until the Mongol invasions in the 13th century. Ibn al-Haytham , better known as Alhazen, used controlled experiments in his optical study. Avicenna 's compilation of the Canon of Medicine , a medical encyclopaedia,

13986-529: The natural draught/draft flow rate by assuming that the molecular mass (i.e., molecular weight) of the flue gas and the external air are equal and that the frictional pressure and heat losses are negligible: Q = C A 2 g H T i − T e T e {\displaystyle Q=C\,A\,{\sqrt {2\,g\,H\,{\frac {T_{i}-T_{e}}{T_{e}}}}}} where: Combining two flows into chimney: A t + A f < A , where A t =7.1 inch

14112-662: The notion that the only function of the eye is perception, and shifted the main focus in optics from the eye to the propagation of light. Kepler is best known, however, for improving Copernicus' heliocentric model through the discovery of Kepler's laws of planetary motion . Kepler did not reject Aristotelian metaphysics and described his work as a search for the Harmony of the Spheres . Galileo had made significant contributions to astronomy, physics and engineering. However, he became persecuted after Pope Urban VIII sentenced him for writing about

14238-447: The older type of study of physics as too purely speculative and lacking in self-criticism . Aristotle in the 4th century BCE created a systematic program of teleological philosophy. In the 3rd century BCE, Greek astronomer Aristarchus of Samos was the first to propose a heliocentric model of the universe, with the Sun at the centre and all the planets orbiting it. Aristarchus's model

14364-598: The past, science was a synonym for "knowledge" or "study", in keeping with its Latin origin. A person who conducted scientific research was called a "natural philosopher" or "man of science". In 1834, William Whewell introduced the term scientist in a review of Mary Somerville 's book On the Connexion of the Physical Sciences , crediting it to "some ingenious gentleman" (possibly himself). Science has no single origin. Rather, systematic methods emerged gradually over

14490-562: The public's attention and caused the onset of environmental studies . During this period scientific experimentation became increasingly larger in scale and funding . The extensive technological innovation stimulated by World War I , World War II , and the Cold War led to competitions between global powers , such as the Space Race and nuclear arms race . Substantial international collaborations were also made, despite armed conflicts. In

14616-470: The results might be. Taken in its entirety, the scientific method allows for highly creative problem solving while minimising the effects of subjective and confirmation bias . Intersubjective verifiability , the ability to reach a consensus and reproduce results, is fundamental to the creation of all scientific knowledge. Chimney In the United States , the term smokestack industry refers to

14742-560: The room. Because the air going up the shaft was cooler, these could be made of less fireproof materials. Another step in the development of chimneys was the use of built-in ovens which allowed the household to bake at home. Industrial chimneys became common in the late 18th century. Chimneys in ordinary dwellings were first built of wood and plaster or mud. Since then chimneys have traditionally been built of brick or stone, both in small and large buildings. Early chimneys were of simple brick construction. Later chimneys were constructed by placing

14868-453: The seminal encyclopaedia Natural History . Positional notation for representing numbers likely emerged between the 3rd and 5th centuries CE along Indian trade routes. This numeral system made efficient arithmetic operations more accessible and would eventually become standard for mathematics worldwide. Due to the collapse of the Western Roman Empire , the 5th century saw an intellectual decline and knowledge of Greek conceptions of

14994-567: The sixteenth century Nicolaus Copernicus formulated a heliocentric model of the Solar System, stating that the planets revolve around the Sun, instead of the geocentric model where the planets and the Sun revolve around the Earth. This was based on a theorem that the orbital periods of the planets are longer as their orbs are farther from the centre of motion, which he found not to agree with Ptolemy's model. Johannes Kepler and others challenged

15120-405: The social sciences, there are many competing theoretical perspectives, many of which are extended through competing research programs such as the functionalists , conflict theorists , and interactionists in sociology. Due to the limitations of conducting controlled experiments involving large groups of individuals or complex situations, social scientists may adopt other research methods such as

15246-450: The structure falls into its own footprint, so as not to damage neighboring structures. This is essential for tall structures in dense urban areas. Any error can be disastrous, however, and some demolitions have failed, severely damaging neighboring structures. One significant danger is from flying debris, which, when improperly prepared for, can kill onlookers. Another dangerous scenario is the partial failure of an attempted implosion. When

15372-406: The swinging ball and the safety implications associated. High reach demolition excavators are more often used for tall buildings where explosive demolition is not appropriate or possible. Excavators with shear attachments are typically used to dismantle steel structural elements. Hydraulic hammers are often used for concrete structures and concrete processing attachments are used to crush concrete to

15498-476: The time. Before the invention or discovery of the concept of phusis or nature by the pre-Socratic philosophers , the same words tend to be used to describe the natural "way" in which a plant grows, and the "way" in which, for example, one tribe worships a particular god. For this reason, it is claimed that these men were the first philosophers in the strict sense and the first to clearly distinguish "nature" and "convention". The early Greek philosophers of

15624-484: The wall of a building. They are generally located adjacent to a steam-generating boiler or industrial furnace and the gases are carried to them with ductwork. Today the use of reinforced concrete has almost entirely replaced brick as a structural element in the construction of industrial chimneys. Refractory bricks are often used as a lining, particularly if the type of fuel being burned generates flue gases containing acids. Modern industrial chimneys sometimes consist of

15750-476: The world deteriorated in Western Europe. During the period, Latin encyclopaedists such as Isidore of Seville preserved the majority of general ancient knowledge. In contrast, because the Byzantine Empire resisted attacks from invaders, they were able to preserve and improve prior learning. John Philoponus , a Byzantine scholar in the 500s, started to question Aristotle's teaching of physics, introducing

15876-501: Was widely rejected because it was believed to violate the laws of physics, while Ptolemy's Almagest , which contains a geocentric description of the Solar System , was accepted through the early Renaissance instead. The inventor and mathematician Archimedes of Syracuse made major contributions to the beginnings of calculus . Pliny the Elder was a Roman writer and polymath, who wrote

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