An insertion device is a component in modern synchrotron light sources, so called because they are "inserted" into accelerator tracks. They are periodic magnetic structures that stimulate brilliant, forward-directed synchrotron radiation emission by forcing a stored charged particle beam to perform wiggles, or undulations, as they pass through the device; this motion is caused by the Lorentz force, it is from this oscillatory motion that we get the names for the two classes of device, which are known as wigglers and undulators. As well as creating a brighter light, some insertion devices enable tuning of the light so that different frequencies can be generated for different applications; the theory behind undulators was developed by Vitaly Ginzburg in the USSR. However it was Motz and his team who in 1953 installed the first undulator in a linac at Stanford, using it to generate millimetre wave radiation through to visible light, it was not until the 1970s that undulators were installed in electron storage rings to produce synchrotron radiation.
The first institutions to take these devices were the Lebedev Physical Institute in Moscow, the Tomsk Polytechnic University. These installations allowed a fuller characterisation of the behaviour of undulators. Undulators only became practical devices for insertion in synchrotron light sources in 1981, when teams at the Lawrence Berkeley National Laboratory, Stanford Synchrotron Radiation Laboratory, at Budker Institute of Nuclear Physics in Russia developed permanent magnetic arrays, known as Halbach arrays, which allowed short repeating periods unachievable with either electromagnetic coils or superconducting coils. Despite their similar function, wigglers were used in storage rings for over a decade before they were used to generate synchrotron radiation for beamlines. Wigglers have a damping effect on storage rings, the function to which they first put at the Cambridge Electron Accelerator in Massachusetts in 1966; the first wiggler used for generation of synchrotron radiation was a 7 pole wiggler installed in the SSRL in 1979.
Since these first insertions the number of undulators and wigglers in synchrotron radiation facilities throughout the world have proliferated and they are one of the driving technologies behind the next generation of light sources, free electron lasers. Insertion devices are traditionally inserted into straight sections of storage rings; as the stored particle beam electrons, pass through the ID the alternating magnetic field experienced by the particles causes their trajectory to undergo a transverse oscillation. The acceleration associated with this movement stimulates the emission of synchrotron radiation. There is little mechanical difference between wigglers and undulators and the criterion used to distinguish between them is the K-Factor; the K-factor is a dimensionless constant defined as: K = q B λ u 2 π β m c where q is the charge of the particle passing through the ID, B is the peak magnetic field of the ID, λ u is the period of the ID, β = v / c relates to the speed, or energy of the particle, m is the mass of the accelerated particle, c is the speed of light.
Wigglers are deemed to have K>>1 and undulators to have K<1. The K-Factor determines the energy of radiation produced, in situations where a range of energy is required the K-number can be modified by varying the strength of the magnetic field of the device. In permanent magnet devices this is done by increasing the gap between the magnet arrays. In electromagnetic devices the magnetic field is changed by varying the current in the magnet coils. In a wiggler the period and the strength of the magnetic field is not tuned to the frequency of radiation produced by the electrons, thus every electron in a bunch radiates independently, the resulting radiation bandwidth is broad. A wiggler can be considered to be series of bending magnets concatenated together, its radiation intensity scales as the number of magnetic poles in the wiggler. In an undulator source the radiation produced by the oscillating electrons interferes constructively with the motion of other electrons, causing the radiation spectrum to have a narrow bandwidth.
The intensity of radiation scales as N 2, where N is the number of poles in the magnet array
A synchrotron is a particular type of cyclic particle accelerator, descended from the cyclotron, in which the accelerating particle beam travels around a fixed closed-loop path. The magnetic field which bends the particle beam into its closed path increases with time during the accelerating process, being synchronized to the increasing kinetic energy of the particles; the synchrotron is one of the first accelerator concepts to enable the construction of large-scale facilities, since bending, beam focusing and acceleration can be separated into different components. The most powerful modern particle accelerators use versions of the synchrotron design; the largest synchrotron-type accelerator the largest particle accelerator in the world, is the 27-kilometre-circumference Large Hadron Collider near Geneva, built in 2008 by the European Organization for Nuclear Research. It can accelerate beams of protons to an energy of 6.5 teraelectronvolts. The synchrotron principle was invented by Vladimir Veksler in 1944.
Edwin McMillan constructed the first electron synchrotron in 1945, arriving at the idea independently, having missed Veksler's publication. The first proton synchrotron was designed by Sir Marcus Oliphant and built in 1952. Several specialized types of synchrotron machines are used today: A storage ring is a special type of synchrotron in which the kinetic energy of the particles is kept constant. A synchrotron light source is a combination of different electron accelerator types, including a storage ring in which the desired electromagnetic radiation is generated; this radiation is used in experimental stations located on different beamlines. In addition to the storage ring, a synchrotron light source contains a linear accelerator and another synchrotron, sometimes called a booster in this context; the linac and the booster are used to successively accelerate the electrons to their final energy before they are magnetically "kicked" into the storage ring. Synchrotron light sources in their entirety are sometimes called "synchrotrons", although this is technically incorrect.
A cyclic collider is a combination of different accelerator types, including two intersecting storage rings and the respective pre-accelerators. The synchrotron evolved from the first cyclic particle accelerator. While a classical cyclotron uses both a constant guiding magnetic field and a constant-frequency electromagnetic field, its successor, the isochronous cyclotron, works by local variations of the guiding magnetic field, adapting the increasing relativistic mass of particles during acceleration. In a synchrotron, this adaptation is done by variation of the magnetic field strength in time, rather than in space. For particles that are not close to the speed of light, the frequency of the applied electromagnetic field may change to follow their non-constant circulation time. By increasing these parameters accordingly as the particles gain energy, their circulation path can be held constant as they are accelerated; this allows the vacuum chamber for the particles to be a large thin torus, rather than a disk as in previous, compact accelerator designs.
The thin profile of the vacuum chamber allowed for a more efficient use of magnetic fields than in a cyclotron, enabling the cost-effective construction of larger synchrotrons. While the first synchrotrons and storage rings like the Cosmotron and ADA used the toroid shape, the strong focusing principle independently discovered by Ernest Courant et al. and Nicholas Christofilos allowed the complete separation of the accelerator into components with specialized functions along the particle path, shaping the path into a round-cornered polygon. Some important components are given by radio frequency cavities for direct acceleration, dipole magnets for deflection of particles, quadrupole / sextupole magnets for beam focusing; the combination of time-dependent guiding magnetic fields and the strong focusing principle enabled the design and operation of modern large-scale accelerator facilities like colliders and synchrotron light sources. The straight sections along the closed path in such facilities are not only required for radio frequency cavities, but for particle detectors and photon generation devices such as wigglers and undulators.
The maximum energy that a cyclic accelerator can impart is limited by the maximum strength of the magnetic fields and the minimum radius of the particle path. Thus one method for increasing the energy limit is to use superconducting magnets, these not being limited by magnetic saturation. Electron/positron accelerators may be limited by the emission of synchrotron radiation, resulting in a partial loss of the particle beam's kinetic energy; the limiting beam energy is reached when the energy lost to the lateral acceleration required to maintain the beam path in a circle equals the energy added each cycle. More powerful accelerators are built by using large radius paths and by using more numerous and more powerful microwave cavities. Lighter particles lose a larger fraction of their energy. Speaking, the energy of electron/positron accelerators is limited by this radiation loss, while this does not play a significant role in the dynamics of proton or ion accelerators; the energy of such accelerators is limited by the strength of magnets and by the cost.
Unlike in a cyclotron, synchrotrons are unable to accelerate particles from zero kinetic energy.
Argonne National Laboratory
Argonne National Laboratory is a science and engineering research national laboratory operated by the University of Chicago Argonne LLC for the United States Department of Energy located in Lemont, outside Chicago. It is the largest national laboratory by scope in the Midwest. Argonne was formed to carry out Enrico Fermi's work on nuclear reactors as part of the Manhattan Project, it was designated as the first national laboratory in the United States on July 1, 1946. In the post-war era the lab focused on non-weapon related nuclear physics and building the first power-producing nuclear reactors, helping design the reactors used by the USA's nuclear navy, a wide variety of similar projects. In 1994 the lab's nuclear mission ended, today it maintains a broad portfolio in basic science research, energy storage and renewable energy, environmental sustainability and national security. UChicago Argonne, LLC, the operator of the laboratory, "brings together the expertise of the University of Chicago with Jacobs Engineering Group Inc."
Argonne is a part of the expanding Illinois Research Corridor. Argonne ran a smaller facility called Argonne National Laboratory-West in Idaho next to the Idaho National Engineering and Environmental Laboratory. In 2005, the two Idaho-based laboratories merged to become the Idaho National Laboratory. Argonne has five main areas of focus; these goals, as stated by the DOE in 2008, consist of: Conducting basic scientific research. Argonne began in 1942 as the "Metallurgical Laboratory" at the University of Chicago, which became part of the Manhattan Project; the Met Lab built Chicago Pile-1, the world's first nuclear reactor, under the stands of a University of Chicago sports stadium. Considered unsafe, in 1943, CP-1 was reconstructed as CP-2, in what is today known as Red Gate Woods but was the Argonne Forest of the Cook County Forest Preserve District near Palos Hills; the lab was named after the surrounding Argonne Forest, which in turn was named after the Forest of Argonne in France where U.
S. troops fought in World War I. Fermi's pile was going to be constructed in the Argonne forest, construction plans were set in motion, but a labor dispute brought the project to a halt. Since speed was paramount, the project was moved to the squash court under Stagg Field, the football field on the campus of the University of Chicago. Fermi told them that he was sure of his calculations, which said that it would not lead to a runaway reaction, which would have contaminated the city. Other activities were added to Argonne over the next five years. On July 1, 1946, the "Metallurgical Laboratory" was formally re-chartered as Argonne National Laboratory for "cooperative research in nucleonics." At the request of the U. S. Atomic Energy Commission, it began developing nuclear reactors for the nation's peaceful nuclear energy program. In the late 1940s and early 1950s, the laboratory moved to a larger location in unincorporated DuPage County and established a remote location in Idaho, called "Argonne-West," to conduct further nuclear research.
In quick succession, the laboratory designed and built Chicago Pile 3, the world's first heavy-water moderated reactor, the Experimental Breeder Reactor I, built in Idaho, which lit a string of four light bulbs with the world's first nuclear-generated electricity in 1951. A complete list of the reactors designed and, in most cases and operated by Argonne can be viewed in the, "Reactors Designed by Argonne" page; the knowledge gained from the Argonne experiments conducted with these reactors 1) formed the foundation for the designs of most of the commercial reactors used throughout the world for electric power generation and 2) inform the current evolving designs of liquid-metal reactors for future commercial power stations. Conducting classified research, the laboratory was secured; such alluring secrecy drew visitors both authorized—including King Leopold III of Belgium and Queen Frederica of Greece—and unauthorized. Shortly past 1 a.m. on February 6, 1951, Argonne guards discovered reporter Paul Harvey near the 10-foot perimeter fence, his coat tangled in the barbed wire.
Searching his car, guards found a prepared four-page broadcast detailing the saga of his unauthorized entrance into a classified "hot zone". He was brought before a federal grand jury on charges of conspiracy to obtain information on national security and transmit it to the public, but was not indicted. Not all nuclear technology went into developing reactors, however. While designing a scanner for reactor fuel elements in 1957, Argonne physicist William Nelson Beck put his own arm inside the scanner and obtained one of the first ultrasound images of the human body. Remote manipulators designed to handle radioactive materials laid the groundwork for more complex machines used to clean up contaminated areas, sealed laboratories or caves. In 1964, the "Janus" reactor opened to study the effects of neutron radiation on biological life, providing research for guidelines on safe exposure levels for workers at power plants and hospitals. Scientists at Argonne pioneered a technique to analyze the moon's surface using alpha radiation, which launched aboard the Surveyor 5 in 1967 and analyzed lunar samples from the Apollo 11 mission.
In addition to nuclear work, the laboratory maintained a
The interdisciplinary field of materials science commonly termed materials science and engineering is the design and discovery of new materials solids. The intellectual origins of materials science stem from the Enlightenment, when researchers began to use analytical thinking from chemistry and engineering to understand ancient, phenomenological observations in metallurgy and mineralogy. Materials science still incorporates elements of physics and engineering; as such, the field was long considered by academic institutions as a sub-field of these related fields. Beginning in the 1940s, materials science began to be more recognized as a specific and distinct field of science and engineering, major technical universities around the world created dedicated schools of the study, within either the Science or Engineering schools, hence the naming. Materials science is a syncretic discipline hybridizing metallurgy, solid-state physics, chemistry, it is the first example of a new academic discipline emerging by fusion rather than fission.
Many of the most pressing scientific problems humans face are due to the limits of the materials that are available and how they are used. Thus, breakthroughs in materials science are to affect the future of technology significantly. Materials scientists emphasize understanding how the history of a material influences its structure, thus the material's properties and performance; the understanding of processing-structure-properties relationships is called the § materials paradigm. This paradigm is used to advance understanding in a variety of research areas, including nanotechnology and metallurgy. Materials science is an important part of forensic engineering and failure analysis – investigating materials, structures or components which fail or do not function as intended, causing personal injury or damage to property; such investigations are key to understanding, for example, the causes of various aviation accidents and incidents. The material of choice of a given era is a defining point. Phrases such as Stone Age, Bronze Age, Iron Age, Steel Age are historic, if arbitrary examples.
Deriving from the manufacture of ceramics and its putative derivative metallurgy, materials science is one of the oldest forms of engineering and applied science. Modern materials science evolved directly from metallurgy, which itself evolved from mining and ceramics and earlier from the use of fire. A major breakthrough in the understanding of materials occurred in the late 19th century, when the American scientist Josiah Willard Gibbs demonstrated that the thermodynamic properties related to atomic structure in various phases are related to the physical properties of a material. Important elements of modern materials science are a product of the space race: the understanding and engineering of the metallic alloys, silica and carbon materials, used in building space vehicles enabling the exploration of space. Materials science has driven, been driven by, the development of revolutionary technologies such as rubbers, plastics and biomaterials. Before the 1960s, many eventual materials science departments were metallurgy or ceramics engineering departments, reflecting the 19th and early 20th century emphasis on metals and ceramics.
The growth of materials science in the United States was catalyzed in part by the Advanced Research Projects Agency, which funded a series of university-hosted laboratories in the early 1960s "to expand the national program of basic research and training in the materials sciences." The field has since broadened to include every class of materials, including ceramics, semiconductors, magnetic materials and nanomaterials classified into three distinct groups: ceramics and polymers. The prominent change in materials science during the recent decades is active usage of computer simulations to find new materials, predict properties, understand phenomena. A material is defined as a substance, intended to be used for certain applications. There are a myriad of materials around us—they can be found in anything from buildings to spacecraft. Materials can be further divided into two classes: crystalline and non-crystalline; the traditional examples of materials are metals, semiconductors and polymers.
New and advanced materials that are being developed include nanomaterials and energy materials to name a few. The basis of materials science involves studying the structure of materials, relating them to their properties. Once a materials scientist knows about this structure-property correlation, they can go on to study the relative performance of a material in a given application; the major determinants of the structure of a material and thus of its properties are its constituent chemical elements and the way in which it has been processed into its final form. These characteristics, taken together and related through the laws of thermodynamics and kinetics, govern a material's microstructure, thus its properties; as mentioned above, structure is one of the most important components of the field of materials science. Materials science examines the structure of materials from the atomic scale, all the way up to the macro scale. Characterization is the way; this involves methods such as diffraction with X-rays, electrons, or neutrons, various forms of spectroscopy and chemical analysis such as Raman spectroscopy, energy-dispersive spectroscopy, thermal analysis, electron microscope analysis, etc.
Planetary science or, more planetology, is the scientific study of planets and planetary systems and the processes that form them. It studies objects ranging in size from micrometeoroids to gas giants, aiming to determine their composition, formation and history, it is a interdisciplinary field growing from astronomy and earth science, but which now incorporates many disciplines, including planetary geology, atmospheric science, hydrology, theoretical planetary science and exoplanetology. Allied disciplines include space physics, when concerned with the effects of the Sun on the bodies of the Solar System, astrobiology. There are interrelated theoretical branches of planetary science. Observational research can involve a combination of space exploration, predominantly with robotic spacecraft missions using remote sensing, comparative, experimental work in Earth-based laboratories; the theoretical component involves mathematical modelling. Planetary scientists are located in the astronomy and physics or Earth sciences departments of universities or research centres, though there are several purely planetary science institutes worldwide.
There are several major conferences each year, a wide range of peer-reviewed journals. In the case of some exclusive planetary scientists, many of whom are in relation to the study of dark matter, they will seek a private research centre and initiate partnership research tasks; the history of planetary science may be said to have begun with the Ancient Greek philosopher Democritus, reported by Hippolytus as saying The ordered worlds are boundless and differ in size, that in some there is neither sun nor moon, but that in others, both are greater than with us, yet with others more in number. And that the intervals between the ordered worlds are unequal, here more and there less, that some increase, others flourish and others decay, here they come into being and there they are eclipsed, but that they are destroyed by colliding with one another. And that some ordered worlds are bare of animals and plants and all water. In more modern times, planetary science began from studies of the unresolved planets.
In this sense, the original planetary astronomer would be Galileo, who discovered the four largest moons of Jupiter, the mountains on the Moon, first observed the rings of Saturn, all objects of intense study. Galileo's study of the lunar mountains in 1609 began the study of extraterrestrial landscapes: his observation "that the Moon does not possess a smooth and polished surface" suggested that it and other worlds might appear "just like the face of the Earth itself". Advances in telescope construction and instrumental resolution allowed increased identification of the atmospheric and surface details of the planets; the Moon was the most studied, as it always exhibited details on its surface, due to its proximity to the Earth, the technological improvements produced more detailed lunar geological knowledge. In this scientific process, the main instruments were astronomical optical telescopes and robotic exploratory spacecraft; the Solar System has now been well-studied, a good overall understanding of the formation and evolution of this planetary system exists.
However, there are large numbers of unsolved questions, the rate of new discoveries is high due to the large number of interplanetary spacecraft exploring the Solar System. This is both a theoretical science. Observational researchers are predominantly concerned with the study of the small bodies of the Solar System: those that are observed by telescopes, both optical and radio, so that characteristics of these bodies such as shape, surface materials and weathering are determined, the history of their formation and evolution can be understood. Theoretical planetary astronomy is concerned with dynamics: the application of the principles of celestial mechanics to the Solar System and extrasolar planetary systems; the best known research topics of planetary geology deal with the planetary bodies in the near vicinity of the Earth: the Moon, the two neighbouring planets: Venus and Mars. Of these, the Moon was studied first. Geomorphology studies the features on planetary surfaces and reconstructs the history of their formation, inferring the physical processes that acted on the surface.
Planetary geomorphology includes the study of several classes of surface features: Impact features Volcanic and tectonic features Space weathering - erosional effects generated by the harsh environment of space. For example, the thin dust cover on the surface of the lunar regolith is a result of micro meteorite bombardment. Hydrological features: the liquid involved can range from water to hydrocarbon and ammonia, depending on the location within the Solar System; the history of a planetary surface can be deciphered by mapping features from top to bottom according to their deposition sequence, as first determined on terrestrial strata by Nicolas Steno. For example, stratigraphic mapping prepared the Apollo astronauts for the field geology they would encounter on their lunar missions. Overlapping sequences were identified on images taken by the Lunar Orbiter program, these were used to prepare a lunar stratigraphic column and geolog
The natural environment encompasses all living and non-living things occurring meaning in this case not artificial. The term is most applied to the Earth or some parts of Earth; this environment encompasses the interaction of all living species, climate and natural resources that affect human survival and economic activity. The concept of the natural environment can be distinguished as components: Complete ecological units that function as natural systems without massive civilized human intervention, including all vegetation, soil, rocks and natural phenomena that occur within their boundaries and their nature. Universal natural resources and physical phenomena that lack clear-cut boundaries, such as air and climate, as well as energy, electric charge, magnetism, not originating from civilized human actions. In contrast to the natural environment is the built environment. In such areas where man has fundamentally transformed landscapes such as urban settings and agricultural land conversion, the natural environment is modified into a simplified human environment.
Acts which seem less extreme, such as building a mud hut or a photovoltaic system in the desert, the modified environment becomes an artificial one. Though many animals build things to provide a better environment for themselves, they are not human, hence beaver dams, the works of Mound-building termites, are thought of as natural. People find natural environments on Earth, naturalness varies in a continuum, from 100% natural in one extreme to 0% natural in the other. More we can consider the different aspects or components of an environment, see that their degree of naturalness is not uniform. If, for instance, in an agricultural field, the mineralogic composition and the structure of its soil are similar to those of an undisturbed forest soil, but the structure is quite different. Natural environment is used as a synonym for habitat. For instance, when we say that the natural environment of giraffes is the savanna. Earth science recognizes 4 spheres, the lithosphere, the hydrosphere, the atmosphere, the biosphere as correspondent to rocks, water and life respectively.
Some scientists include, as part of the spheres of the Earth, the cryosphere as a distinct portion of the hydrosphere, as well as the pedosphere as an active and intermixed sphere. Earth science, is an all-embracing term for the sciences related to the planet Earth. There are four major disciplines in earth sciences, namely geography, geology and geodesy; these major disciplines use physics, biology and mathematics to build a qualitative and quantitative understanding of the principal areas or spheres of Earth. The Earth's crust, or lithosphere, is the outermost solid surface of the planet and is chemically and mechanically different from underlying mantle, it has been generated by igneous processes in which magma cools and solidifies to form solid rock. Beneath the lithosphere lies the mantle, heated by the decay of radioactive elements; the mantle though solid is in a state of rheic convection. This convection process causes the lithospheric plates to move, albeit slowly; the resulting process is known as plate tectonics.
Volcanoes result from the melting of subducted crust material or of rising mantle at mid-ocean ridges and mantle plumes. Most water is found in another natural kind of body of water. An ocean is a major body of saline water, a component of the hydrosphere. 71% of the Earth's surface is covered by ocean, a continuous body of water, customarily divided into several principal oceans and smaller seas. More than half of this area is over 3,000 meters deep. Average oceanic salinity is around 35 parts per thousand, nearly all seawater has a salinity in the range of 30 to 38 ppt. Though recognized as several'separate' oceans, these waters comprise one global, interconnected body of salt water referred to as the World Ocean or global ocean; the deep seabeds are more than half the Earth's surface, are among the least-modified natural environments. The major oceanic divisions are defined in part by the continents, various archipelagos, other criteria: these divisions are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean and the Arctic Ocean.
A river is a natural watercourse freshwater, flowing toward an ocean, a lake, a sea or another river. A few rivers flow into the ground and dry up before reaching another body of water; the water in a river is in a channel, made up of a stream bed between banks. In larger rivers there is a wider floodplain shaped by waters over-topping the channel. Flood plains may be wide in relation to the size of the river channel. Rivers are a part of the hydrological cycle. Water within a river is collected from precipitation through surface runoff, groundwater recharge and the release of water stored in glaciers and snowpacks. Small rivers may be termed by several other names, including stream and brook, their current is confined within a stream banks. Streams play an important corridor role in connecting fragmented habitats and thus in conserving biodiversity; the study of streams and waterways in general is known as surface hydrology. A lake is a terrain feature, a body of water, localized to the bottom of basin.
A body of water is considered a lake when it is inland, is not part
Biology is the natural science that studies life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms and evolution. Despite the complexity of the science, there are certain unifying concepts that consolidate it into a single, coherent field. Biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, evolution as the engine that propels the creation and extinction of species. Living organisms are open systems that survive by transforming energy and decreasing their local entropy to maintain a stable and vital condition defined as homeostasis. Sub-disciplines of biology are defined by the research methods employed and the kind of system studied: theoretical biology uses mathematical methods to formulate quantitative models while experimental biology performs empirical experiments to test the validity of proposed theories and understand the mechanisms underlying life and how it appeared and evolved from non-living matter about 4 billion years ago through a gradual increase in the complexity of the system.
See branches of biology. The term biology is derived from the Greek word βίος, bios, "life" and the suffix -λογία, -logia, "study of." The Latin-language form of the term first appeared in 1736 when Swedish scientist Carl Linnaeus used biologi in his Bibliotheca botanica. It was used again in 1766 in a work entitled Philosophiae naturalis sive physicae: tomus III, continens geologian, phytologian generalis, by Michael Christoph Hanov, a disciple of Christian Wolff; the first German use, was in a 1771 translation of Linnaeus' work. In 1797, Theodor Georg August Roose used the term in the preface of a book, Grundzüge der Lehre van der Lebenskraft. Karl Friedrich Burdach used the term in 1800 in a more restricted sense of the study of human beings from a morphological and psychological perspective; the term came into its modern usage with the six-volume treatise Biologie, oder Philosophie der lebenden Natur by Gottfried Reinhold Treviranus, who announced: The objects of our research will be the different forms and manifestations of life, the conditions and laws under which these phenomena occur, the causes through which they have been effected.
The science that concerns itself with these objects we will indicate by the name biology or the doctrine of life. Although modern biology is a recent development, sciences related to and included within it have been studied since ancient times. Natural philosophy was studied as early as the ancient civilizations of Mesopotamia, the Indian subcontinent, China. However, the origins of modern biology and its approach to the study of nature are most traced back to ancient Greece. While the formal study of medicine dates back to Hippocrates, it was Aristotle who contributed most extensively to the development of biology. Important are his History of Animals and other works where he showed naturalist leanings, more empirical works that focused on biological causation and the diversity of life. Aristotle's successor at the Lyceum, wrote a series of books on botany that survived as the most important contribution of antiquity to the plant sciences into the Middle Ages. Scholars of the medieval Islamic world who wrote on biology included al-Jahiz, Al-Dīnawarī, who wrote on botany, Rhazes who wrote on anatomy and physiology.
Medicine was well studied by Islamic scholars working in Greek philosopher traditions, while natural history drew on Aristotelian thought in upholding a fixed hierarchy of life. Biology began to develop and grow with Anton van Leeuwenhoek's dramatic improvement of the microscope, it was that scholars discovered spermatozoa, bacteria and the diversity of microscopic life. Investigations by Jan Swammerdam led to new interest in entomology and helped to develop the basic techniques of microscopic dissection and staining. Advances in microscopy had a profound impact on biological thinking. In the early 19th century, a number of biologists pointed to the central importance of the cell. In 1838, Schleiden and Schwann began promoting the now universal ideas that the basic unit of organisms is the cell and that individual cells have all the characteristics of life, although they opposed the idea that all cells come from the division of other cells. Thanks to the work of Robert Remak and Rudolf Virchow, however, by the 1860s most biologists accepted all three tenets of what came to be known as cell theory.
Meanwhile and classification became the focus of natural historians. Carl Linnaeus published a basic taxonomy for the natural world in 1735, in the 1750s introduced scientific names for all his species. Georges-Louis Leclerc, Comte de Buffon, treated species as artificial categories and living forms as malleable—even suggesting the possibility of common descent. Although he was opposed to evolution, Buffon is a key figure in the history of evolutionary thought. Serious evolutionary thinking originated with the works of Jean-Baptiste Lamarck, the first to present a coherent theory of evolution, he posited that evolution was the result of environmental stress on properties of animals, meaning that the more and rigorously an organ was used, the more complex and efficient it would become, thus adapting the animal to its environment. Lamarck believed that these acquired traits could be passed on to the animal's offspring, who would